DOCTORAL DISSERTATION SERIES TITLE SWUti en CHEMICAL MfWtDS tt 4QI/ATIt pmt cmuL iiif u i m m urn a m m L a u th o r htMAM DIE1 UUktitlj universitym i m s r m cm, DEGREE f l l j , DATE PUBLICATION NO. B./+.+^A /tS! A M li I MVnr MKKIUIS A N N ARBOR • M I C H I G A N S'TJDTES OH CHEMICAL METHODS 0? AQUATIC ?LAHT COSTROL I* PRESHWATEH LAKES AHD POJSTDS Hornian 0. Levardeen A THESIS ub'iltted to the School of Graduate £tidier of l!ichi,--*a £ta+e C o l l c t of Agriculture nr.' Applied Science in partial fulfillment of the requirements for the decree of DOCTOR OP PHILOSOPHY Department of BotanT1 and Plant Pathology l?51 jlcetowledomepps The writer wishes to express his indebtedness to Dr. B. H. Grigsby, department of Botany and Plant Pathology, Michigan State College, under ■/nose direction this work was done; to the Institute for Pisheries Re­ search, Michigan Department of Conservation, whose fellowship made the investigation possible and to its director, Dr. A. S. Hazzard. The writer is also indebted to the personnel at the Hastings Pish Hatchery for courtesies extended in connection with the work at the hatchery ponds, to William Cristanelli of the Institute staff for assistance in preparing the illustrations, to Sheldon Hedges for making the water chemistry analysis in connection with the nigrosine eaqperiment at the fish hatchery and to Dr. R. C. Ball, Zoology Department, Michigan State College, for counsel and suggestions during the investigation. STUDIES Off CHEMICAL METHODS OP AQUATIC PLAffT C0HTR0L IK FRESHWATER LAKES A"rD POKES 3y JT^r v n 0. Lovnrdre ~i r*n*' '*•v-'1 •V.• «*V.Ox OW S'Limit tec' to the School of Grr.dvjrt e St^idier of Mi chirm Stn-.ft Colle-p cf Arric'iltrre ar.'1 Applied Science in partial f"lff! In ant. of th« roe u.irrr.e:.t • fur t%erlod. TelletE of either 2,fc-T or 2,^,5-* did not control submerged v/eeds TTornan 0. Levardsen When districted on the bottom of shallow water at concentrations con­ sidered to he practical. Pellets composed of 2»4-D and pentachloro- phenol were effective and rapid in action. The translocated herbicides were found to he superior to contact herbicides in the control of floating and emergent aquatic jilants. Rootrtoc’c reserves were sufficiently.” high so that even when the exposed vegetative growth was killed with a contact spray, regrowth occurred. When translocated herbicides were utilized, best control was obtained when Applications coincided with the first appearance of flowers. Some species required repeat applications when regrowth became estcblished. TABLE 07 CONTEXTS Acr:novl ed raent s Abstract Table of Contents Introduction Review of Li terat’i r e .......................... 3 Materials nr/ Method? Remits . • .................... 6 ................... 16 Ni.jrocine....................... 16 Chlorinated Rensener end Xylene . . . 31 2 th-Z P e l l e t s ....................55 Trnr.rlocnted Herbicider. . . . . . . 67 Contact Herbicide?. . . . . . . . . 85 2 i s c u s s l o n ............................. 101 S u n n & r y ............................... Ill Literature Cited Appendix IflTOOIttTCTTOE The present study was undertaken as the result of an increase In interest relating to the control of aquatic vegetation in recreational orcnr and "because of the relative scarcity of information concerning wend control in aquatic habitats. The Fisheries Division of the Mich­ igan Department of Conservation, as well as other state agencies, have veen asked repeatedly to advise in these natters and have been unable to supply rdesunta information. In view of recent developments in the use of herbicides for the control of terrestrial weeds, it was felt that an evaluation of these materials for the control of water weeds would represent a valuable addition to the available information. In the fall of 19^? a cooperative agreement was made between Mi chi.ran St-te College and the Institute for Fisheries Sesearch, whereby a fellowship in aquatic weed control war established. The study was to be made under the supervision of the Department of Botany and Plant Pathology, Michigan State College. The material presented in this report represents a compilation of the results of that investigation. A rather broad study was undertaken with the view of evaluating the commercially available materials reported i1' *he liternt’ire as being effective herbicides. The investigation of new materials and the development of new methods for the control of both submerged and emergent aquatic plants also have been undertaken. The major portion of the study lnrolred field work during the summer months. This was done* in the main* at the following stations: Bess lake, '/evaygo County; the State Pish HAtohery, Bastings, Barry County, and at Lake Lansing, Inghan County. Other areas were Loon Lake, Bifle Hirer Area, Ogemaw County; Portage Creek Trout Pond, Jackson County, and Bast Mill Pond, near Borneo, Macomb County. Baclllties at Michigan State College were utilised for greenhouse and laboratory phases of the study. 3 B x n s v or litjratorb Aside from the use of sodium arsenlte and copper nil fate, which are veil documented in the literature and are outside the general scope of this paper, the literature (1?), relative to the chemical control of sub­ merged weeds, is less voluminous than that pertaining to emergent aquatics. The introduction of the use of chlorinated benzene (1*0 probably marks the beginning of the present era of control of entirely submerged weeds by rheolcal means. In the Irrigation canals of the western United States, this material has been extensively utilised (10). It also has been used In lake8 (23)* A new development, the use of petroleum naphthas (12), •larked another advance in aquatic weed control, at least in irrigation projects. Good control of cattail, Tnaha latlfolla. with one application of the butyl ester of 2,**-D, was reported by Bauman (*0 • tributyl phosphate, with kerosene as carrier When 2,*M) in was used, favorable control was reported by Surber, et. al. (21) and by Cornell (6). WAlker (22), as did Jackson (ll), found it more economical to cut cattails under water than to spray with 2,h-3>. Spraying the cattails when the average height of the new growth had reached 3j to U feet gave good results (1). Handley (9) had best results from spraying in the spring with either the butyl or the isopropyl ester of 2 .U-D when the blades were approximately 2 h inches tall. Better results with repeat applications, than with single appli­ cations, were obtained by Snow (16) and by Wilson and Tinney (2**). u When ammonium sulfamte was need in controlling cattails, Bauman (5) M d not achieve entirely satisfactory remits. Ammonium sulfanate gave -mplete kill of cattails on dry land, but some root tips survived and -raw vhen the sprayed cattails were standing in water (l). It was found 10et satisfactory to spray at the beginning of the floweringperiod. Bauman (*0 found that it did not seen to natter at what stage of •rovth arrowhead, Saglttarla latlfolla. was sprayed, for It v&s still 'ery susceptible to 2,h-D. Any 2 ,h-D preparation in a carrier of diesel '’uel. or water was effective, according to Snov (1^) . Surber (19) had ood success with a one percent aeneous snray of 2 ,^-D. Wher cr'-ovkend vas sprayed early in the spring, as the plants made their first appearance. Tandlay (9 ) achieved effective control hy using the butyl ester of 2 ,h-D. When aoronium sulfamate was used, Bauman (5) did not obtain satis­ factory control of arrowhead even by using r wetting agent. Effective control of piekerelweed, Pontederla cordata. was obtained %y Bauman (k) with the "butyl ester of 2 ,fc-D, applied while the plants •ere in full bloon. Surber, et. al. (21) effected good control of white water lily, ■Ty.hnea sun.. when a pond was drained and the erposed leaves and petioles ••ere sprayed with 2,h—D in tributylphosphete. Burther study "by Surber (19) Indicated that Wrrrohaea could be killed with t\:c percent 2 ,^-D in tributylh-fphate with oil ae carrier. nster of 'now (1 6 ). Several an-llcntionr of either the salt or were necessary for cer.trol of this species as found by Handley (9) found. BrTTohe.ee odorata fairly resistant to 2,^4-B •r.d haa beet success when the leaves were sprayed early in the spring sir.'* either the butyl or iespropyl erter of 2 ,h-D. |5 More then a single application ©f 2,4-D « u required to control ioftstem bulrush, Sclnrus velidus. ae reported by Surber, et. al. (21). 1 percent solution of 2,h-D in tributylphosptaate to be effective on soft-stern bulrush. A was found by Surber (19) Handley (9) ted best results by spraying with the ester of 2 ,h-D early in the spring when the plants were approximately 12 inches tall. The butyl ester of 2,4—D was found to be effective on spatterdoclc, Nutter advena. by Bauman (4). Surface sprays with 2,4-L in tributyl- phosphate, as reported by Surber, et.al. (21), vere ineffective. (9) stated Handley that Nunhar advena proved extremely resistant to 2,4-D and found even repeated treatments not completely successful. He had best results when treatments with 2,4—L were made at the time the leaves first appeared in the spring. Spat terdo ok, treated with 2,4—D in late May and with ammonium sulfaoate in late June, was reported by Steenis (18) to have s given over 96 percent control. Surber, et. al. (21) did not find ammonium sulfaoate effective when used at the rate of 10 pounds per acre. Smith and Swingle (15) reported that sprays of creosote and fuel oil, sodium chlorate, and sodium arsenlte killed only the leaves. In the treatment of submerged aquatics with 2,4-D, Gerklng (8) estimated that it would cost approximately $ 16? to treat a acre pond having about 25,- acre feet of water. Xicher (7) described field trials in which nigroslne dye was added to lake water in order to reduce the penetration of sunlight into the lake and thus inhibit the growth of aquatic vegetation by slow starvation of the pleats. He stated that the water remained dark into the following season and greatest effect of the dye was then notloed because normal, 6 semi-emergent aquatic plants failed to reach the surface. fho biological effects of nigrosine Aye, used for the oontrol of weeds In hatchery ponds, vas reported hy Surher and Srerhart (20). They stated that nigrosine dye had no harmful effects on sunflsh or hass at concentrations required to control weeds. MATERIALS AND METHODS The aquatic plant- used in tnip study -nd emergent species. inr^jtV flouting, submerged Some of the submerged were rooted In the bottom '•nder several feet of water and never reached the surface. The emergent ■'pecies were either on weter-lo^-ed soil or standing in water. The names 'f the plants which were included in the experimental work, according to Jh^ classification of Ifuer.ccher (1?), are as follows: 0171 ST Or OHLOROPHYTA Characeae fites spp. DIVISION SPERMATOPHYTA Typhacsae Treha angustlfolla L. Narrow—leaved cattail Tut?ha latlfolla L. Common cattail 7 PIYISIOV SPXBN1TQPHTTA (Continued) Potamogetonaoeae Potamogeton ^anpllfollas Tucker* Broad- 1eared pondweed apihyflms Baf. Potamogeton natans L. Potamogeton oectlnatue L. Sago pondweed Potamogeton rlchardsonl! Bydb. Potamogeton robbinell Oakes. Potamogeton ^osterlformla Pernald Hajadaceae ^Tajas 3pp. Allamaceae Saglttarla latIfolla Willd. Arrowhead, Duck potato Hydrocharitaeeae Anacharls canadensls (Michx.) Planchon Vail 13nerla anerlcana Michx. Waterweed, Elodea Wild celery, "Eelgrass’* Cyperaceae S e l m a ralldue Vahl. Great bulrush, Softstem “bulrush Pontederiaeeae Heteranthera dubla (Jacq.) MacM Pontederla cordata L, Pickerelweed 8 DIVISION SPBBHATCFHm (Continued) Cerp-t ophyllao< Ceratonhrllum denersun L. Uymphaeac eae Brasenla schreberl Grnel. Water shield Uuohar ad vena Alt. Tellow water lily, Spat terdock Ilvnahaea odorata Ait. White water lily Rairunctilac eae Baminculug flabellaris Haf. Yellov vater-crovfoot Hal ora~i dn ceae ilrrio-ohrrllun vertlclllatum L. Compoaitae Bldens beckll Torr.. Water marigold To study the effect of mixtures of xylene and trichlorbensene on submerged species, it was necessary to secure suitable emulsifying agents. Vp-rious proprietary compounds were used and are shown, with the names of the manufacturer, in the following list. SJTJLSIFIEaS Material HfttTVtftefryW Antarox A-AOO General Aniline A ?lla Corp. Dresslnate 91 Hercules Powder Co. 9 MULSITISBS (Oontirroed) Material Manufacturer G-1255 and 0-1283 Atlas Powder Co« Glyceryl Laurate 3909 Olyoo Products Co* Inc. Glyceryl Laurate S Olyco Products Co. Inc. Intracol "M" Synthetic Chemicals, Inc, Mulsor Synthetic Chemicals, Inc, Mulsor 77 Synthetic Chemicals, Inc. Neutronyx 8 3 ^ Onyx Oil Ss Chemical Co. Petroraix ? L. Sonnehorn Sons, Inc. Spans ^0, 60, 6 5 . 80, 85 Atlas Powder Co. Sterox SK Monsanto Chemical Co. Sulfonated castor oil Tweens ^0 , 6 0 , 6 5 . 80, 85 Atlas Powder Co. The number of chemical compounds available for weed control purposes is large. this study. It was not possible to include all of these in Among those used were nigrosine dye, various types of contact herbicides and some of the translocated growth regulating compounds. The materials used are as follows: HERSTCIUSS AMD OTHER COMPOUNDS Jjaterial Composition Manufacturer Animate ammonium sulfamate The Sow Chemical Co, Ammonium thlocyacate ammonium thiocyanate J.T.SeJcer Chem. Co. 10 HERBICIDES ASD OTHER C0MP0UHD8 (Continued) Ifelszl&l Ooaruoeition Amyl acetate aoyl acetate Ber.oclor 3 ortho- and trichloro- Clorohen Corp. benzenes Penoclor 3C ortho-and trichloro- Clorohen Corp. henzen.es (added emulsifier) Chlorosol A alpha-hydroxy-beta- Pitts. Agr. Chen. Co. trichlorethyl sulfonic acid Diehloro Pentanes dlchloro pentanes Sharpies Chen*s. Inc. Dowcide G sodinn pentaehloro- The Dow Chemical Co. phenate Dow Weer> Hiller Cfor.nl a i<0) Ester or. 4*4 alkanolanine salts The Dow Chemical Co. of 2,4-D 1sopropyl ester The Dow Chemical Co. of 2.4-D Esteron 2,*i,5 butyl ester of 2,4,5-' The Dow Chemical Co. pentachlorophenol The Dow Chemical Co. in oil Eir.r-O-Cldc phenyl acetic acid J. T. Smith Chen. Co. and. 2,4—D ITi^rosine (not known) General Aniline & Film !Tirrosine (not known) Allied Chea.& Dye Corp. 11 HERBICIDES AMD OTHER C0NP00HD6 (Continued) Material Composition Manufacturer Orthodichlorbenzene orthodichlorobenzene The Dow Chemical Co. Polybor sodium pentaborate Pacific Coast Borax Co. Sodium 2,^-D (8?^) sodium salt of 2,U-D 2.X. du Pont de Menours Weed Killer Sodi uu TOA (70f&) and Company sodium trichloro- The Dow Chemical Co. acetate Trichlorbenzene trichlorbenzene The Dow Chemical Co. Weed-lTo -More butyl ester of 2,^4-D Shervin Williams Xylene xyl ene 1*7398 petroleum dis­ The Standard Oil Co. of Indiana tillates When quantities of herbicides larger than a quart were to he al lied to terrestrial weeds, a hnapsach sprayer (Pig. 1) was utilized. ?his was of copper construction and of four-gallon capacity. The angle of spray could he adjusted by rotating the nozzle which was of the hollow cone type. In order to include as many field trials as possible in the seasons1 activities, small-scale applications of herbicides on sub­ merged r.quatie weeds were a necessity. Murabered stakes were placed •t random through a fairly homogeneous bed of weeds said allowed to rojeet above the surfhoe. Hone were placed closer than six feet 12 • apart. A Sure Shot Spray or of either five—ounce or one-quart eapaoity '»s used. It vat soon Ait core red that when a sprayer was held in the orthodox position, with handle up and the noszle pointing downward, the contents could not he completely emptied. The only practical way of eliminating this was to bend the noszle extension to a verti­ cal position (Fig. 2), so that the s^ray would be directed downwards •rhile the sorayer was held in the customary manner. The general proceedure was to pour the mixture, including ten percent of water to aid enrulsification, into the sprayer, tighten the cap with a wrench and fill the remainder of the space with com­ pressed air from a tank (Fig. 3) * holding on to the 3take with one hand and holding the sprayer, with the nozzle extending below the surface, in the other, the contents could readily be emptied over n rather small area surrounding the stake. The appearance of the emulsion, just subsequent to spraying, is illustrated in Fig. 4. For the treatment of large areas of submerged weeds, a Spartan Sprayer was utilised. This punp v/as of the tvo-cylinder type, capa­ ble of pressures up to 250 pounds per square inch. It was thus ade­ quate for the proper emulsification of the balanced mixtures. The arrangement of the spray apparatus and solution tank is shown in Fir. 5 . Fig. 6 shows the boon attachment to the stern of the boat. The sprayer wae compact and, when placed in the stern of a boat, could be operated by one nan (Fig.7)» For the more accurate laying out of plots, a nylon clothesline •vas used. This was equipped with fish net floats at eight foot in— 13 tervals to keep the line at the surface. A wire core in the line elim­ inated much of the stretch of the nylon. Working from a boat, it was ruite easy to lay out plots of fairly uniform size. Once the plots were laid out (Fig. 8) it was not difficult to scatter the pellets or to apply liquid herbicides quite uniformly within the plot con­ fines . Where small plots were used, ? x 3 or 6 x 6 feet, frequently only one marker was used. Once the marker was in place, the required amount of pelleted material was distributed about the stake, covering an area approximately 3 * 3 or 6 x 6 feet. Occasionally four bamboo poles were ited together to form a 6 x 6 foot square and the pellets were distributed within this scuare. Ir. field trials with pelleted samples of 2,4-D, 2 ,^,5-T and 1,^-D-PCP at Hess Leke, Lake Lansing and at the Hastings Fish Hatchery, various methods of staking out and marking plots were used. One method, which worked well in some areas, consisted of the following: four-inch lengths of two by fours were cut, shellacked and then painted with two :ootc of a bright yellow, high gloss enamel. The letters "M.S.O.” were then printed conspicuously on one side, together with an index number. On the other side was placed a staple to which was attached a length of copper fish line. used as anchors. Odds and ends of old pipe fittings vere In setting out these markers, an effort was made to have the floats suspended et least twenty inches below the surface, so os to eliminate possible damage and movement due to ice. When it was desired to obtain numerical data relative to the abun- 1U 'Since of certain weeds, a counting frame was utilised. This was con- rtrusted of four pieces of lath, rivetted together to enclose an area of one square yard. If cattails were to he counted, one eide of the 'raoe was left open. In use, the two sides were held parallel and were pushed Into a stand of cattails. A yardstick was utilised to see that the sides of the frame were parallel and that one square yard was en­ closed . During the course of the investigation, several experimental carrples of variously compounded nigrosine dyes were secured and de­ terminations nade on the light occlusion properties of ea.ch dye. In the evaluation of these dyes, a modified Jp.ckson Turbidimeter was used. This was constructed by invertin'- a lh ounce fruit Juice can over a 15 watt electric light bulb. The light from the bulb was allowed to pass through a hole in the bottom of the fruit Juice can and u; through a five-sixteenths inch circle painted on the bottom of a 200 ml. graduate. The graduate was enclosed by a cardboard tube, to exclude incident light, thus making possible a more accurate readir.~. The home-made turbidimeter is illustrated in Figures 9 *^<3 10* In the use of this instrument, the dye solution was poured slow­ ly into the graduate until the light image Just disappeared. Then, with a pipette, small quantities were withdrawn until the image reepgeared. A few drops of the solution added was usually sufficient to cause extinction of the light and at this point no further dye solution was added. The cardboard tube was then removed and a road­ ie- of the level of the dye solution made directly from the scale on 15 *he qrnduAte. This scale almost exactly corresponded to millimeters ■‘‘r'-r’ the base of the water column, so that volume readings could he 5’"rctly converted to millimeters. The margin of error was 3 nm* in rim., 1.2 percent, which was not considered significant. It is customary to refer to applications of phenoxyacetic acid compound.s and Ha TCA as being of so many pounds, acid equivalent, or acre. In this report, all references to dosage rates follow tills custom. 16 -RESULTS Nigrosine The lake chosen for the nigrosine experiment was Loon Lake in the Michigan Department of Conservation's Rifle River Area, Ogemaw County. The lake is mainly spring-fed and in normal years the evaporation and seepage equal the supply so that little water is lost throu^i the outlet. Although all the lakes in the area were open to fishing. Loon Lake was the least used beeause the nuisance of weeds interfered with rowing and fishing. Loon Lake is set fairly low* surrounded by hills so that it 18 not exposed to the wind aetion which is developed on larger, more open lakes. The turbidity was, in general, greater than that of the other lakes in the area. Practically all the plants in the lake were growing within the fire foot contour. 100 ppm. and the pH 8.0 The methyl orange alkalinity was about indicating a fairly alkaline condition. The water level was at least six inches below normal due to a very dry spring. plants in several areas were so heavily coated with marl that they were bent over and did not interfere with row­ ing. A large patch of Anacharls canadensis. near the outlet, although discolored by marl, was Just about to the surface and slowed up a boat drifting through it. ’M f * * dredge samples were taken in the deeper waters and it appeared that no rooted aquatic plants were growing in water over ten feet deep. The soft, pulpy peat on the bottom made it difficult to determine the exact depth of the i*ter. 17 The main weed species vere as f o l l o w I Anacharls canadensis gunhar advena Chara spp. Potamogeton sosterlformls Myrlo-ohyllun) Tertlclllatua Valllsnerla amerlcana Application of the dye to Loon Lake eae made on July 17* 19*t£« In making the application, the dye eae divided into three parte and distri­ bution made by sprinkling the dry granules off the stern of a boat in three lanes which traversed the length of the lake* The eater, in the eeke of the boat, colored immediately and diffusion eas fairly rapid. In the course of a fee hours, the currents had so merged the color that the lanes eere scarcely perceptible. Coverage eas considered to be com­ plete in 2M hours. Before the application of the dye the Secehl disk had disappeared at five feet. open eater. Twenty-four hours later the reading eae three feet in the In the shallows, the marl-coated ff canadensis plants vere conspicuous against the blackness of the eater. The lake SLgeln eas examined on August 13th, at which time the Secchi disk disappeared at 5 feet 6 inches. The caretaker at the area had per­ iodically taken Secchi disk readings and these indicated a gradual in­ crease in transparency over the intervening period. The marl-coated Anacharls canadensis plants did not appear to have been affected by the 'brief period of darkness as the leaves were of a normal, green color when the lime was removed. Xelgrass. Talllsneria aaerlcaaa. had become conspicuous in several areas and the terminal portions of Ceraton^yllmp domsrsum were within a few inches of the surfhce. 18 Dae to the method of application, it was suspected that soae of the crystals ml^it hare fallen into the layer of rery li^it and fine, pulpy peat and become buried. To establish whether these crystals existed and had formed a henry dye solution which would not diffuse through the pul­ py peat, the following test was One made on August 13th: of the lames, made wnen the crystals were distributed,had be­ gun within a core and passed out of the mouth into the lake proper. A furrow, ten to fifteen Inches deep, was dug in the pulpy peat of the soft bottom across the mouth of the bay; at right angles to the lame of crys­ tals. The stirred peat settled rapidly so that by the tine the furrow was finished, the water looked normal where first disturbed. in water about one and one-half in the water after the silt had feet deep. This was No blue coloration persisted settled. On September 25th. the Secchi disk disappeared at seven feet. water level was down about 10 inches due to the dry summer weed beds The and several which previously had not come to the surface, had now con­ tacted the surface, from a comparison of the growth of plants beyond stakes which had been put in to mark the extent of two beds of Chara and one of **>»>»»>«,»■0 that readings of 310* do not Indicate equal absolute turbidItlee periodically (Tig* 11)* In Table II the result* are tabulated as to the number of days required for clearing of the dye solution* In srery ease vhere the dye cleared, evidence of nigrosine was to be found in one or all of three places* clumps of dye could be plainly seen on the leaf surfaces of the plants, entrapped or chemically associated with the pre­ cipitate of lime on the sides of the Jars, on the bottom of the Jar in clumps or associated with lime deposits* In an effort to see whether the type of water was a factor in the clearing of a dye solution, nine Jars together with 3500 ml. of water vere placed in each of *02 gms* of the dye used at Loon Lake and were set up as follows: 1 . dye only Tap water 2. dye and Anacharlg canadensl s 3 * dye and 10 grams muck 1 . dye only Distilled water 2. dye and Anach&ris canadensis 3 * dye and 10 grans muck 1 . dye only Lake water 2. dye and Anacharlg canadensis 3 * dye and 10 grams muck The Jars were set up on March 31. 1950, and were allowed to remain in the greenhouse. A glass plate was set orer each Jar top to reduce evaporation. On April 22nd. in the Ho. 1 series, the distilled water Jar was quite blue with the tap water Just sli^itly clearer. darks b t and had a precipitate on the bottom. The lake water Jar was the The tap water Jar had a slight precipitate but none was evident in distilled water. In the No. 2 series the tap water was sll^itly bluer than the other two. The plants in tap water appeared normal, with the older leaves and^g TABLE II RESULTS Q? JAR TESTS VITH NIGROSIHZ DYE SAMPLES Conoontratlon (ppa.) Rato of Cloaring 11odea and nod Initial 1st 2nd. Total 2.8 2.8 5.7 5.7 5.7 5-7 5.7 5.7 7.1 I 7.1 5.7 12.8 Gnat TABLE II (Contlmed) Dy* Concentration (ppn) Dye 3 1st. 2nd. 2.8 8.5 Days 11 25 Slodea and nod Degree Days m m 11 18 Degree Qrans m m Mater Mod alone 10 Ifcyi Degree ays m 11 10 ; 24 H 18 m 88 ♦ 52 ♦ *5 - 34.2 12 24 - 34.2 34.2 25 24 - 42.75 42.75 21 85-50 36 28.5 21 57.0 28 m 85-5 38 m 28.5 7 m 7 m 10 7 ♦ 57.0 27 m 27 h 10 14 - 85.5 *5 m *5 10 *5 m 28.5 28.5 28.5 28.5 28.5 28.5 Degree 11 : 34.2 42.75 6 Total 2.8 5*7 5 Elodaa alone Additions Initial Bata of Cloarlag ♦ m ♦ TABLE II (Continued) Dye Concentration (ppo) r — ■ ■ ... .... Bate of Clearing . XLodea alone Xlodea and not Total Days Days 28.5 21 m 57.0 28 m 85.5 38 H 2.8 2 m 8.4 14 14.0 5.7 5.7 5-7 5.7 11.4 11.4 30 H 11.4 11.4 45 28.4 28.4 45 Additions Dye Initial 7 1st. 2nd. 28.5 2B.5 28.5 8 2.8 5.6 5-6 a-1155 lueresoeln Degree Degree Mater Mad alone Grass ®*JS Degree Day. Degree 38 ee eee 2 m 10 2 see 2 so 14 H 10 35 eee 45 e 35 see 35 m 10 45 eee 13 m 10 30 e 30 e 25 30 - m *5 eee m 45 eee * &urk e slight lightening to faintly ooldred m elear 25 axils containing dye deposits on them hut none appeared on the new, green leaves. The plants in distilled water appeared normal short sprigs which were hleaehed* except for two On the upper trarfaoe of the older leaves. lime deposits and spots of dye were visible. The plants in distilled and lake water had grown satisfactorily. In the Vo. 3 series the dye concentration appeared to he Just about the same in all jars. The Jar containing tap water had a greater growth ◦f algae on the surface than did the others. On June 1st. the jar with the tap water In the No. 1 series was very much lighter in color than was the distilled water jar. The lake water was intermediate in color hut appeared to hare a reddish cast rather than the blue of the distilled water. In the No. 2 series the jar with the lake water was absolutely clear. A slight growth of a filamentous algae was present on the bottom. Anacharis canaden 8ls was still green and was giring off oxygen bubbles near the top. The distilled water jar was almost as clear as the lake water Jar but the Anacharis canadensls was not growing satisfactorily because filamentous algae had developed in the Jar. The tap water Jar was not colored from the dye but contained colonial algae and Invertebrate life. Some of the Anacharls canadensis plants appeared normal. In the No. 3 series the tap water was almost clear, just slightly stained. A n algal growth was developing on the surface. The distilled water was still dark from dye but had a green surface scum of algae. The lake water was clear but had numerous algal filaments. The solutions and plants were discarded SLfter this examination be­ cause of algae growths. Plants in control Jars had grown well through— 26 out the experiment. To determine what effect solutions of nigroslne at different pH levels might hare on the clearing of the dyed water, the following experiments were conducted: One-£pllon jars with buffered solutions of tap water in the follow­ ing pH ranges were set up according to tables by Clark and Lubbs: pH 6.0 6.5 7.0 7.5 8.0 8.5 At once it was apparent that aluminum or other salts were forming an unstable suspension, especially in the alkaline range. Within 2U hours, the four hl^iest buffered solutions (from pH 7*0 to 8.5) con­ tained a white precipitate. On the 15th. of March, two days after the solutions vere made, the clear water above the cloudy layer was siph­ oned off and enough tap water (which usually amounted to 100 ml.) was added to bring the quantity up to 3500 ml. The Jars vere then placed in the greenhouse. In each was placed sufficient nlgroslne dye Ho. 3 to give a concentration of 5*7 ppm. assuring complete solution of the dye a generous amount of canadensis was placed in each Jar. After ^ The Jars were then covered with glass plates to reduce evaporation. On March 22nd. they were examined and the results vere found to be as follows: the plants appeared to be growing best at a pH of 6.0 Here the concentration of dye appeared to be the least of any of the Jars. At a pH of 6.5 most of the terminal growths of Anachar is were flaccid. plants At pH of 7.0 and above all the plant parts were flaccid 27 and the Jars smelled of putrefaction, especially those in the higher pH range. Jars containing water of pH of 6.5 and 7.0 were darkest and did not appear to hare had as nmch dye taken out of solution as did the Jars above this range which were limiter in color. At the time of the last inspection, before the contents of the Jars vere discarded, It was noted that only at pH of 6.0 was there any evi­ dence of plant life. The other Jars did not contain any living plants and the solution of none of them was as clear as that at p H 6.0 It was noticed in cleaning the Jars that the Jar at pH 6.5 seemed to have had the greatest deposition of lime on the sides and bottom of the Jar. At the Hastings Fish Hatchery, Pond Ho. 8 has produced annually a very luxuriant crop of weeds, chiefly Anachar is canadensis and Ranun­ culus flabellarls. This pond had received artificial fertilisation during the growing season in the experimental rearing of bait minnows. It was .75 acres in area and sloped in to a depth of about 6 feet in the center and near the drain basin. On June 21, 195^» sixteen pounds of Rational Nigroslne 128-B were put in the pond. This was at the rate of 21.3 pounds per acre. method of distribution was as follows: portions. the dye was divided into three These, one at a time, were placed in the bottom of a pall and the pall filled with water. agulate The When water was added, the dye seemed to co­ forming large, hard lumps that slowly dissolved. Bis 16 pounds were distributed by walking around the edge of the pond in the shallow water and periodically allowing the pall to fill with water, subsequent­ ly pouring out the dye solution. Following this method of introduction and to aid dispersion, the concentrated dye solution near the shore was 28 pushed out toward the center of the pond by means of hoards. By the next day the dye had colored the open water in the center and was considered to he of uniform distribution after two days. The Sec chi disk reading* Just previous to applying the dye, was one foot* This and subsequent readings were taken from a bo x which enclosed the outletat the deepest part of the pond. On June 26th., flTe days after putting in the dye, the Seechl disk reading was I*- feet. This, therefore, indicated that the decreased penetration of light following application of the dye was only temporary. A week after application of the dye, the shallow water appeared to be clearing and this fact was confirmed by Secchl disk readings. When fragments of the plants were examined, they showed black deposits on the leaves, especially on the upper surface of the Anachar is eanadenel s leaves. Fertilizer was added on June 29th. On July 1st., three weeks after the initial application, another treatment of 15 pounds of dye was made. This was placed in the bottom of a 10 gallon milk can, after which the can was filled with water. By means of a portable power sprayer, the supernatant liquid was sprayed over the surface of the pond. As the level of the dye solution in the can fell, it was replaced by water taken from the pond until there were no more lumps in the bottom of the can. A week later the Secchl disk reading was l-V feet, and on July 10th. it On the 18th. of July determinations was 2 feet. of the oxygen dioxide concentrations of the water were made. and carbon At this time the oxygen level was 1.1 ppm. and the carbon dioxide at 39.0 ppm. The Seechi disk disappeared at 3 feet. VIth m e n a low oxygen content It vat faarad for tha safety of the red-eared sunflsh which vara In the pond for othar experimental porpoaaa. The vater, which had been abut off to prarant di lutlon of tha dye, vaa than allowed to ran Into tha pond. this Shortly after two daya of heavy rain occurred to that on July 21 at. tha oxygen content vaa up to 4.2 ppm. and tha oarbon dioxide vaa down to 0.0 ppm. In order to prove more definitely that tha addition of the dye and subsequent coloring of tha water can cauaa a depletion in the oxygen con tent of the subaurface water, another 15 pounde of dye vere put In on August 4th. At this time the water to the pond was turned off and the dye distributed by means of a burlap sack of the crystals dragged be­ hind the boat. The oxygen content at thif» time was 11.4 ppm. with 0.0 ppm. carbon dioxide. Three daya later the Secchl disk reading was one foot, the oxygen vaa down to 1.98 ppm. and the carbon dioxide concentration was up to 11.0 ppm. On the 11th. of August the light penetration vaa two feet, the oxygen content at 2.6 ppm. and the carbon dioxide at 11.0 ppm. At this time another 15 pounds of dye vere introduced by means of a cotton bag filled with crystals and toved behind a boat. When plants vere pulled from the deeper water (the tops vere in the photosynthetic cone) for examination, it was noticed that the lover stems of Anacharls canadensis vere bare of leaves. gid and not brittle. pond. These stems, however, vere green, tur­ An odor of putrefaction vas noticeable around the Bullheads were noticed in distress and seemingly gulping for air at the surface on August 14th. A week after adding the dye the oxygen content vas 2.3 ppm. and the carbon dioxide was 14.0 ppm. Additional applications probably vould hare caused further re­ duction In oxygen concentration and this might hare affected tha fish adversely, therefore ly dye applications vere stopped. Share vas apparent­ little or no effects upon tha veeds (other than the hare stems) as they remained In a normal condition throughout the remainder of the summer. Results of the analyses of veter samples and Secchl disk readings obtained during the course of dye treatments sLre shovn In Table III. TABLE III EFFECT QF APPLICATIONS OF NIGBOSISE DTE OH OXIDIS, CABBON DIOXIDE, PHXfTOU'flTHAUEII ALEALIIITT, MBTHTL ORANG1 AIZALIHITT AND DEPTH OF PXBETSATIQN OF LIGHT June July August Sate Hat. Dj% added (In pound*) 26th. 16 let. 7th. 10th. 18th. 21at. 15 1.1 Carton dioxide (In ppn.) 39. 4.2 13. j 0.0 4.0 Methyl orange alkalinity (in ppn.) 24.0 1 132.0 Benarke eater turned off 1.5 i 2. 3. eater turned on 1.98 11.4 0.0 : 11. 0.0 Uth. 18th. 25th. 15 0.0 Phenolphthaleln alkalinity (In ppn.) 1.5 7th. 15 Oxygen (In pp«.) Secchl dlek (in feet) 4th. 2.6 11. 0.0 144. 142. 167. 1. 1. 2. eater 1 turned off 2.3 14. 0.0 178. 2. eater tuned on 31 CHLORINATED B T O B T R S AHD XTLXSZ In the beginning of the research on this problem, information relative to the effective cheaieal eontrol of submerged aquatic plants vas limited to the following materials: 1. Sodium arsenlte 2. Copper sulfate 3* Benoclor 4. Orthodichlorobeneene 5* Petroleum naphthas The first ia well documented in the literature. The second ie known to be effective on Ohara but, in concentrations required for eontrol. highly toxic to animal life. animal life. The last tvc, is Benoclor is also known to be very toxic to 'V robonzene (one of theingredients of Benoclor) and the petroleum naphthas are worthy of attention because of their cheapness, when compared to Benoclor, their availability, and their effectiveness even though it was known that fish life would not survive in treated waters. field trials during the first summer of experimental work included applications of Benoclor, orthodichlorobenzene, xylene and toluene. These will be discussed beginning with the experiments at last Mill Pond. An emulsifiable mixture of orthodichlorobenzene and trlchlorobensene (No. 3) has had, during the past 13 years, a considerable use as an aquatic herbicide. Recently a material (No. JQ ) containing a greater amount of emulsifying agent has been available. This was designed primarily for aquatic weed control in the flowing waters of irrigation canals of western United States but is useful also in shallow, standing waters of laker. One drum of each of the materials was applied at last Mill Pond, near Romeo, Michigan, during the latter part of July 19**?. Vhen the material (Vo. JC ) containing most eonlsifier was sprayed beneath the surface of the water, a cloudy emulsion was formed. This emulsion, as it slowly settled to the bottom, came in contact with the submerged weeds. The other material (Vo. 3) containing a smaller quantity of emulsifier, did not form as good an emulsion as the material containing the greater amount of emulsifier. Vo. 3C was apolied in the shallow water wheras the Vo. 3 material was applied in the deeper water because the emulsion of the latter tends to sink quite rapidly. Results of these applications were not considered satisfactory as the weeds were only temporarily retarded and a considerable number of fish were killed. Two additional drums of material were obtained for experimental use during the 19^8 season. A more complete check on the vegetation was to be made at this time with close attention to be paid to calcu­ lation of dosages. An outline of the areas treated is given in Jig. 13 and the treatments are given in Table 17. Prom the latter it will be seen that the rates varied from 26 to 6h gallons per acre during the 19^9 season. A description of the areas and treatments follows: Aren "A" was covered by means of the lane method, applying Vo. JC next to shore and Vo. 3 in the deeper water. The aquatic plants in this area were mainly Chare. Potamogeton eplhydrus. Vunhar advene. ff?retophyUam demersun and anachar is from shore. j« were present in the deeper water 25 fee t TABLE I1II API’LXCATIONS Of CHLORINATED BENZ2HES AT SA8T MILL PORI), 19^7-19^ Date Material 1 7l2lM Bo. *30 20 2 7/21/1*7 Bo. #3 10 1 5/29/1*8 Bo. *30 18 2 5/29/1*8 Bo. *3 16 1 7/21/1*7 Bo. #3C 10 2 7/21/1*7 Be. *3 15 1 7/21M Bo. *30 5 2 7/21/1*7 Bo. *3 5 1 5/29/H8 Bo. *30 8 2 5/29/1*8 Bo. #3 18 1 7/29/1*7 Be. #30 25 2 7/29/1*7 Bo. *3 25 1 A 2 5/29/1*8 Bo. *30 1*0 1 5/29/1*8 Be. *30 16 2 5/29/1*8 Bo. *3 32 5/29/H8 Be. *30 6* A m A B C D E r Bate per Aere (la gallone) 33 In area "C" Ohara and Baaunculus flabel laris practically surrounded the Island. The foraer was mostly confined to the shallow part and merged in with the Ranunculus flabellaris which lay in the deeper water. In addition to these, Anachar is canadensis was coanon on the north and south aides of the island. On the south side a floating-leered pondweed, Potamogeton enlhydrus. formed an upper-atory orer the Anachar la canaden­ sis and Oeratonfaarllum demersum on the bottom. Scattered about, especial­ ly on the eastern and southern sides, were the floating 1seres of Pota­ mogeton natans. Hrmnhaea odorata and Potamogeton zosterlfomls. Growth of Potamogeton oectlnatus came to the surface in area "D", was very dense and uniformly distributed. the flop-tiag leares of Potamogeton natans. Scattered throughout were In this plot only Ho. ?C was used. In area M2M Anacharis canadensis was the most conspicuous weed, especially in the eastern and northeastern portions. The remainder of the plot consisted, for the most part, of Nuphar adrena and SSBS&SSASft flabellaris. Sixteen gallons of Ho. 3 were put in the deeper water while eight gallons of Ho. 3C was applied in the shallow water next to shore. The shorewsord half and the east end of plot "7* consisted of a practically pure stand of Chara. In the remainder of the plot, the surface was well cowered with the floating leares of Potamogeton pa taps and algae. Beneath this mat vere scattered plants of Banunculus fla­ bellaris and Ceratoohyllum demersum. Scattered lily pads, Hrmfrhasa odorata. floated near the shore. The results of the treatments of these areas were as followst yu Two weeks after treatment, the Potamogeton -neatlt^tmi in area *D* was etlll up to the surface and was in fruit. Tourteen weeks after treatment, the speoles was falling apart on the bottom and was partially cowered with a layer of algae. By late June of the year following, it was obvious, hy the stand of £• -pectlnatus that was developing, that the tubers had not been affected. acre Two sprayings of ho and 50 gallons per did not give sufficient evidence of control to warrant further treetmant. Tor a time, during June and early July, it treatment of area "A* had been effective. appeared as though the Two weeks after treatment, Cerato-phyllum demersum and some Anachar Is canadensis appeared dead and on the bottom. The water was turbid, perhaps as a result of decay and putrefaction of plant parts. Samples taken with an Xkraan dredge from the bottom of the deeper part of the area, failed to bring up any por­ tions of live plants. In the shallows, the water was clear, with some debris on the bottom. A few scattered leaves of were present Just under the surface. growth was appearing all over the area. Two months after treatment, re­ Bottom samples Indicated that the Ceratonhvllum demersum was making regrowth. In the shallows, scattered plants of Anacharls canadensis and Ceratooharllum demersum were appearing, but It was not until late the following summer that the area developed the density of weed growth that had been apparent Just previous to spraying. In area •C", two weeks after treatment, new vegetative growth of Ranunculus flabel laris was Just beginning to appear from the sheaths at the base of Injured leaves. These new leaves continued developing 35 •until two months after spraying, at which tine the plant* began to eettle and fall apart* apparently from natural causes ber all that remained was debris on the bottom. so that by early Septem­ Submerged leares of Potamogeton natans and £. enlhrdrus vere apparently killed but the floating leares did not appear to be affected b y the underwater sprayingr. Chare was not seriously harmed by the application but shoved re­ growth by the end of the stunner. In the shoreward part of area ■E" Ranunculus flabellarlB. two weeks after srraying, was aj.parently dead end on the bottom. summer there vag only debris left on the bottom of Euohar adrena. At the end of the underneath the leares By midsummer of the following yeer, little Ranunculus flabel 1ar 1s came to the surface and Anachar! s canadensis appeared to be as dense as Ranunculus flabellarls had beer. Although Chare was completely destroyed in area "F", it was noted that plants adjoining the treated area, soon crowded into the cleared water. The treatment was rery effect ire on Ceratophrllum demersum and Anachar!s canadensis under the Potamogeton natans. Less effective con­ trol was obtained near the southern margin which adjoined untreated water and whore some dilution probably occurred. The filamentous nl y c s e a , which Just about completely covered the surface of the vn+er, did not np err t o be related to the r e m i t s of the treatment (thr dc-tv '’nd deor.p of the Chnr«0 s Lrvoe the water outside the treated '■— o'* air j hr.d r heavy rlyne scun. The presence of small colonies of Ana churl r crnr-dens is and Cera t ophy 1 lum deraersua near the shore car. ’cvhc c, v e attributed to the action of the algae met which moved with ’ha.-.'-es in wind direction and thus was* an agent in distributing weed 36 fragments. At Eastings, treatments were made using orthodichlorbensene at rates ranging from Uo to 80 gallons per acre with no emulsifier* Aside from the fish kill, which accompanied every treatment, several other observations vere made from these applications. Even at kO gallons per acre, growth of Anachar is canadensis was re­ duced over nuch of the plot area and in a month*s time a n estimated 30 percent of the bottom was clear. greater portion was clear. At higgler concentrations, a considerably In every case there was extensive putre­ faction which became evident when an oar was thrust into the bottom. This was especially noticeable where 80 gallons per acre had been applied. A month after such a treatment, Anacharls canadensis plants appeared to have separated at the soil level and it was possible to ob­ tain an oarful of the loose weeds, vheras in untreated areas were firmly attached to the substratum. they This effect was also observed, but to a lesser extent, in plots where lov/or r? had been applied. By p'-rly Sej'tember, approximately two monthr after treatment, in every plot there vere some normal plants, apparently rooted on the bottom, while other nr eee in the plots had no living plants. At Hess Lake, applications were made on August 21 as follows: Plot H o . 1 Rate >er acre Pnm Material 53.0 gallons hoo orthodichlorbensene 69.6 gallons 573 xylene 72.0 gallons 555 toluene 37 These materials contained rulfonated castor oil at approximately three percent by volume and had a snail amount of water added Just before By means of a sprayer, powered by a gasoline engine, the spraying. materials vere sprayed beneath the surface at 200 pounds pressure. When the area was next examined, effects of the treatments were noticeable in all plots. The predominate weeds in plot Ho. 1 were M t 1p-uh-rllun vertlclllatun and Chara. Huphar advena imo present. In the shoreward part of the plot The leaves of Urrlcrahrllua vertlclllatum appeared to have faller. and the bare stems were all that remained, low ever, new shoots could be observed at the basal regions and these continued growth until cold weather. was disintegrating. In Hos. 2 and J than in plot Ho. 1. Much of the Chara on the bottom Uuvihar advena wac unaffected. the effects of the materials were less noticeable Some of the leaves of Mvr1oohyllun vertIclllatun vere brown but others vere not. Ho effects of the treatments could be observed on Chara. To further test the effectiveness of xylene, four applications were nrde et Hastings, September ? as follows: Rate ner acre 2as* Emulsifier 1. l6o gallons 2.^50 10 percent e 160 gallons 2.^50 10 percent ?. 320 gallons U .900 5 £>erccn* tte 160 gallons 2,^50 10 percent 212* J&. * At the tine of the next examination, three weehs later, the terminal ort tone of phara were found to be whitened in plot Ho. 1. Under this thin 38 4 layer, the rest of the Chara appeared normal. Plot No. 2 contained principally AnaehAris canadensis and Kadas etna. The latter species appeared to hare been more sererely affected by the treatment than did A. canadensis. Much of the Ha.1as became flaccid and vree on the hot torn under going decay. This growth of lft.1e.fl had “been near the s^irfaco at the time of application and therefore had been exposed to the emulsion for a longer period, of time than the Anacharie canadensis which was at a slightly greater depth. New rhizoidal roots were seen on fragments of Anacharlr canadensis. The application of xylene at the rate cf ?20 gallons per acre Rppeered to hav^ been effective in controlling Potenogeton nectlnatus and Na.las ytro. ac thrro species v.-ere apparently dead and dlsinterra-t inr on the bottom.The treatment., however, did rot prevent e elurtp of Polygonum in the center of the plot from flowering. In No. h only in scattered erear was Na.las controlled. it persisted together with Potamogeton : entlnatus Elsewhere as isolated colonies which were in a healthy condition. Small tubers were being formed In the case of P. meetinatus. In the use of these materials, the cost of emulsifier significant portion of the expense. constitutes a Sulfonated castor oil and mahogany roep were recommended by Pelcom (2) for use with the petroleum naphthas. Ir. the flowing waters of irrigation ditches of the western United States, where there compounds find videcpree.d usage, it has been determined that the temperature of the water will affect the amount of emulsifier re­ quired for satisfaetory enulslfication (2). The material applied at Hess Iahe did not emulsify as well as might 39 have been desired. The September Applications at Heatings where 5 and 10 percent of emulsifier vas used, were superior in this respect* On the basis of observations made on spray applications it appeared that Insufficient information was available relative to the Influence of the type of emulsifier on the quality of the emulsion "nd that a study should be made with the view of finding those emulsifiers most effective with the materials used in Michigan waters. The heavy and light materials varied considerably from the specific gravity of water. For example, the specific gravity of xylene is about .86 0 and for orthodlchlorobenzene 1*30. In the case of the light ma­ terials, it was desired to maintain them in suspension for at least an hour before they came to the surface. For the heavy materials it was desired to maintain them in a suspended form for at least an hour before they sank to the bottom. This hour of contact was selected as a stan­ dard because such a time Interval would allow for sufficient contact be­ tween weed plants and herbioldal suspensions to bring about a kill of the plants. Since cost is an important factor in weed control practices, efforts were directed toward the use of as small an amount of emulsifier as possi­ ble and still achieve the desired result. The procedure in evaluating emulsifiers consisted essentially of adding emulsifiers to 10 ml. of ortnodichiorobensene, trichlorbensene, xylene, etc. and, after thorough aggitation, shaking this mixture with 90 ml. of water in a tall, 100 ml. graduate and observing the rats of settling. basis. The quantity of emulsifier added was calculated on a volume 40 In general, when 5 or 10 percent of certain emulsifiers were used, there was little settling within an hour's time. However, 5 percent was considered to he too costly when used on a field scale. Efforts were then directed toward reducing this amount and still achieving the de­ sired hour of suspension. Bie "best method found to achieve this goal was to mix ll^it and heavy materials. They were mutually miscible and the addition of one to another in any proportion caused the specific gravity to he closer to that of water, than was either sepp.rc.tely. The fir"t attempt at mixing was that of combining 5 ml. of orthodichlorobenzene (heavy) with 5 ml. of xylene (light) and a very small quantity of Tween 40. When this mixture was shaken and poured into a graduate containing 90 ml. of water, a fairly good emulsion formed immediately. TJpon shaking the graduate vigorously, a uniform cloudy emulsion resulted, which showed no separation after an hour's time. Subsequently a layer began to form on the bottom. Other trial 8 with different proportions and different emulsifiers were made. Seven ml. of xylene and 3 ml. of orthodichlorobenzene, plus a little sulfouated castor oil water. formed a good emulsion when shaken with Eighteen hours later the top 10 ml. in the graduate (here was the nlxt ire) was clear and there was no settling on the bottom. It was soon found that by eliminating the emulsifier from the r.ixtnre, one or two drops of the mixture, falling through a water col­ umn, would reveal whether the mixture was properly balanced. If the drops cane Immediately to the surface, the mixture was obviously too light. If a drop fell rapidly through the 90 ml. column of water, that 41 Indicated the mixture to he too heavy and would require the addition of lighter component. By ruch a series of trials it was possible to a-rive at the particular combinations desired which were near the preetfic gravity of water or sll^itly heavier. With some of the materials the balanced mixtures appeared to be as *’ollows: orthodichlorobsnxene-jQ'lene as i: 2 trichlorbenzene-xylens as 1 :3 The desired balance was that the mixture be slightly heavier than water as most emulsifiers are light and the addition of them would lower th#' specific gravity of the mixture. 3y early summer of 19**9 sufficient lnformrtlon had been gathered to that field applications were warranted. Three quarter-aere plots ••ere staked out at Hess Lake in Newaygo Co. The weeds present were Chara. Po tamo freton amllfolius. Uymuhaea odorata. and Najas s o p . The lots were laid out nore or less paralleling the chore so that the same 'epth of water (approximately 2 \ to 3 If feet) would be encountered in each flot and so that the weed growths would be more or less similar. materials used were as follows: Ratio trichlorbenzene-xylene orthodichlorobensene-7898 2:3 ort hodi chlorobenzeae-a^l ene 1:2 Ten gallons of each of the above balanced mixtures were used The r 42 making the applications at the rate of 40 gallons per acre. Adding vater to the mixture at the tine of spraying seemed to aid the formation of the evulsion vhen the material vat sprayed beneath the surface. Aaonnt of erml sifler added vas calculated at 2 percent of the balanced mixture. By neans of a John Bean Spartan Sprayer vith a 15 gallon tank, de­ livering about 3 gallons per minute at 200 pounds pressure. It vas possi­ ble to spray the 10 gallons fairly uniformly over the quarter-acre plots by criss-crossing vith a rovboat. The spray boom consisted of four 650067 Tee-Jet nozzles on 18 inch extensions, extending belov the -urface of the water and at 18 inch intervals. The date of application '^.s June 21st. The emulsion of the orthodiehlorbenzene-xylene mixture did not stay up very well and separated quite rapidly. This rapid breaking vas not ’esired as it prevented materials from remaining in contact vith the plants for the desired period of time. Subsequent examinations failed to show any effects in plots other than that sprayed vith the trichiorbenzene mixture. In this plot the Chara, a week later, was down on the bottom and covered with a filamentous algae. composition was taking place for Apparently anaerobic de­ vhen an oar was stuck in to mounds of the debris, bubbles of ill-smelling gas came to the surface. On this same date, June 29th., ten gallons of the trichlorbenzenexylene (1:?) mixture plus 2 percent emulsifier ter-acre plot near shore. was ap lied to a quar- Chara was predominant here vith scattered plants of Mrrloohullum vertlclllatum. Potamogeton vagjnatus and ftajas jjgp. The coverage was good and the material stayed up satisfactorily. weeks later Two the Chara no longer remained upright but m s prostrate and *3 ^rasriented. C h w > , In falling to the hotton, appeared to take vith It snecies of plants the rrrt of the season, f r m plant growth. and leave the plot relatively clear. Daring the bottom of this area remained virtually free A year later there vae still a greet difference he- tv'een the treated and untreated plots hut individual plants of Mvrl- oohyllnr vert1oillatun and Potaraogeton vaglnatus vere present. Other applications, later in the season, vere made vith this mixture and vith the orthodiehlorhenaene-xylene mixture. Applications on specie v other then Chara did not produce as good results. On July 11 a plot,about one— sixteenth of an acre, vas sprayed at ‘he rate of 160 gallons per acre with the triehlorbennene-xylene nurture plus two percent sulfona.ted castor oil as emulsifier. The bottom war covered vith Chara and occasional plants of Potamogeton an 1 ifcllns . 'To. The applications vas made with the pover sprayer and 650067 nosxles. Durin^ the treatment raneroiir m a l l to one inchir> length, fish, three- were seen 4n distress. The next day the Chara had whitened er.d looked dar*, tuci r. s it \/:uld 1 coh after heirm exposed to the eir for a short period of tine. Potr.n o geton arrol 1follus did ‘ad drifted to shore not appeer to he affected. The small fish and it was estimated thrt there vere from three * o four rup.rte of then. Three veelce after treatment, there still was no effect on the Pota— mo ret on acnllfollus. Chara . although it was hleached, was beginning to put put new shoots in the axils. the mixture vas applied. At this time another ten gallons of Chara, two weeks after this second, tree.tment. vac a narently dead and disintegrating. The Potaraogeton caullfollug 44 r«:ne.ined unaffected. Bxaml nation of the plot on June 14th. of the year following, re­ vealed the complete*" absence of Ohara. Bren areas Juet outside the plot where some drifting of the mixture had occurred, shoved a Chara-leas ■bottom. *hara. With a plant hook, it vas impossible to find any fragments of No notioeable difference vas to be observed in the growth of ?o tamo get on aarollfollus. It and a narrow-leaved form of Potamogeton were (growing normally and already had their flowering spikes to the surface. On August 18, 1949, five gallons of the trichlorbensene-xylene pixtnre (1:3) vas sprayed over the surface of a plot (50 by 40 feet) with an average depth of about two feet. This was in the northeast corner of pond No. 11 at the Hastings Pish Hatchery and was at the rate of 108 gallons per acre. The area was almost completely filled with Anacharls canadensis and some Heteranthera dubla. A week later the white, soft, decayed* terminal portions of Anacharls canadensis were very conspicuous against the dark background. An oar, dipped Into the water and weed mass, brou^it up a load of dead, brittle A. canadensis tops. The lower portions, however, were green and rhcved new shoots one inch long. The same type of regrowth was noted in the oase of Heteranthera dubla. which appeared dead, but new shoots were developing from the bases. caying, filamentous algae bluegills. On the surface, bits of floating, de­ supported leeeh carcasses Other bluegills were seen in distress. and several dead A few were found resting on seml—submerged pond scum and vhen disturbed with a paddle, swam blindly into suspended mats of algae. Rowing a boat in the area *5 seemed to bring more fish into difficulty. The chemicals were probably brought into suspension again by the agitation caused by rowing the boat. !To risible drops of oil came to the surface. Subsequent examinations during the summer indicated continued rerrovth of both species.A surface spraying ly not as successful as On August 29th. of the mixture is apparent­ a subsurface one. at Lake Lansing, fire gallons of the trlchlor- ber.zene-xylene (1x3) mixture vas applied beneath the surface in an area 50 by 50 feet. This vas at the rate of 87 gallonsper acre. The plants vere ▼alllsnerla amerlcana. Potamogeton ampllfollus . P. sosterlformls. P. rlchardsonll and Heteranthera dubla. The mixture vas applied at 200 pounds pressure using Ho. 650067 Tee-Jet nozzles. Been during and after tre-xtaeiit, it was noticed that the suspension tended to drift shore ward so that along the outer edge of the plot, the material did not re­ main long in contact vith were seen in distress. the weeds. Quite a few small,one— inch fish A six and one-half inch pickerel was picked up and rerired by being placed in clean water. Tire days later the results were very noticeable. Orer most of the treated area, and that for ten or twelve feet shoreward, the Talllsnerla aaerlcana leaves, which were about one and one-half feet long, were on the bottom. They ver® bleached white and transparent Pote-aogeton zosterlfornls. as were those of Basal portions of both appeared normal. P. a-r^Hfo!lus vas affected least of all. The leaves were -erhaps a little off color but the basal portions were green and the rootstooks were normal. Heteranthera dubla stems were still slightly green in color at the internodee but the leaves were bleached. *6 Two weeks later one or two new, green leaves of Potamogeton am-oll- follus stood out In sharp contrast to the rest of the bottom with Its pulpy peat and browned leaves of other plants* There was no regrowth of Velllsnerla amerlcaaa. The following summer £• auspllfo^lus came to the surface In parts of the plot and thus Indicated that It had not been affected very seriously by the treatment. Tall loner la aaerlcana and Chara were rare In the plot. The last field application with the mixture for the season, was on Se tenber 6, 19^9. M the time of spraying, two gallons were added to the mixture which consisted of one gallon of orthodichlorbenxene, two gallons of xylene and 250 ml. of sulfonAted castor oil. This was sprayed beneath the surface at high pressure, 250 pounds per square inch, over an area approximately 50 by ho feet at the rate of 65 gallons per acre* The surface was well covered with the leaves of Brasenla schreberi. Underneath the surface, Tallisnerla amerlcana, Heteranthera dubla and Potamogeton zosterlformls were common. A week later it was estimated that 90 percent of the Brasenla schreberi leaves were under the surface and turning brown. Heteranthera dubla appeared severely Injured and the blackened, decaying plants and rootstocks could be pulled from the bottom, easily. canr. leaves were dead and on the bottom. Tallisnerla amert- Ceratonharllum ftemersum leaves were brown and the stems were brittle. The following year It was obvious that Brasenla schreberi In the plot vas distinctly than In areas outside the plot. demersum. canadensis. There vas still evidence of Ceratonhvllua This nay have drifted in Talllsneria thinner as apparently did some Anacharls vtl still present and was apparently not permanently retarded 'by the treatment a. It had been observed that differences exist between surface and subsurface water temperatures. Ho information was available as to the effect of different temperatures on the rate of settling of different mixtures. A series of experiments directed at this particular problem, that is the effect of temperature on the settling of emulsions, was made. Table V Indicates the results of these experiments and represents the average of four and in some cases six trials. Amount of emulsifier vas calculated at ar> roxlraately two percent. ?ield trials indicated that insufficient information had been ac­ quired relative to emulsifiers when used with balanced mixtures. Some emulsifiers which seemed to form a satisfactory emulsion with one balanced mixture were not satisfactory with another. A comparison in the amount of settling of trichlorbensene, xylene and a balanced mixture of the two, as effected by various amounts of emulsifier, is shown in Table VI. method of evaluation was similar to that described earlier. The The amount of settling represents the average of four trials and was recorded one hour after the materials had been shaken with lake water in tall, 100 ml. graduates. Drops of emulsifier were those which fell from the end of a three mm. stirring rod. The mixtures had a specific gravity of 1.013 An evaluation of emulsifiers for use with balanced mixtures given in Table 711. is Lake Lansing water was utilised and emulsifiers at approximately two percent by volume. It is likely that some of the emulsifiers Indicated as not being very satisfactory by altering the ratio s u b t l y . could be aade so The effects of different emulsifiers on balanced mixtures of xylene-trichlorbensene is shown in Fig. 12. TABLE T ▲ COMPARISON IH THE BASE 07 8BTTLIH& 07 DIJTEHJBT TRXCHLOHBXraHSX I Z J O MIXTURES AT DITFBQBI TEMPJBATOBXS PSIEB TWXEH 60 AS XMOLSXTXXR AID 10 ML. 07 THE MIXTURE Trlahlorbengono-Xarlona Bhti© 15° 0. hr. 1 hr. 1)2 5. nl. 1»2.5 1*3 25° 0. 1 hr. 1& hr. I, hr. 7.4 nl. 10.0 nl. 4.4 ad. 6.4 nl. 10.6 nl. 3- ml. 4.5 nl. 6.7 nil. 2.0 n l. 4.2 nl. 6.2 ml. 0. ml. 2.0 8)1. 3.25ml. 0.0 8)1. 0.0 8)1. 2.2 nl. TABLE li hr. 71 A COMPARISON IH THE AMOOHT 07 8BTTLIH0 07 TRIOHLOHBSNZSTS, XTLZHE AMD A BALANCED MIXTURE 07 THE TWO AS ATTESTED BT DXT7ZRZ2JT AMOUHTS 07 EMPLSITIER ( 1 ! 1 TrlahlorhonsonoXjrlono (1*3) Ajwront of Eonlolflor (Twion 40) Triohlorhonoono 2 dropo 13.5 nl. 3*0 nl. 14.0 ad. 4 dropo 13.0 nl. 0.0 nl. 8.0 ad. 6 .dropo 13.0 8)1. 0.0 hi. 5*0 ad. 8 dropo 13.0 nl. ........ 0.0 ad. 6.0 ad. ____ I Xylono _ I YI TABLE rat:: ob ssttliiig of i c :il. ”'al'*nced Mixture o? th>; balamced i Ratio Sul forated caetor oil XylenrTrleM orbenzenc 3*1 ilylent— Crthodic’ .ilorbcnzone 2:1 Ttatlo TIeutronjrx 8^ ¥¥¥ m * ■ halaxxced I'lxturo. Antarox A<4cr Intraool ■ r Glycerol Laura to ■........... _ ! ietronl: Sr>an L'wcen ^0 hylenr- 3*1 Trlc?ilorl!P*i‘'one ♦t+ Xyl one-Ortho- 2:1 dichlorbo.'se-xe —■ — Talrncrd Vixture ratio bylene'"richi orbenzene ril :\*'l©nrOrthodichlor- ?:1 r " ♦♦♦ T' . ... ; 2 ptr.S’jan P$ 1 ut. 5 > m 85 I 1 pt.Spen 85 3 utr.Soan6o ^ pt.Tween 85 * 3 y>tB.Twoen85 j 1 ?t.T*:een85 ! 1 pt .Tveen-'O -i— t 1 3 ««- ¥¥¥ ¥¥ ¥¥ ber.renc ♦ ♦♦ ¥¥¥ ¥¥¥¥ Settling Settling Sattline Settling Settling o i 10 o:1C of 5 of 5 of 0 nl. 1: nl. 1: nl. lr nil. It nl. lr ix ru ir:s w it h v a r io u s a -m L s iriH is anulelfler* l-hilsor Mulsor V7 ♦♦ Storox SK G—12S3 0-1255 1 Dresinate 91 »♦» ee ~ ♦e «4t> ! ee i - S;>an 60 Tween 60 ♦ ♦♦ ♦♦♦♦ S,An 65 Spar. 80 Span - Tween 85 8 5 — ee - ♦e j i ! 1 ++*’ 1 t .bi>a.n 60 tr.. T w e o n 6 c eee 1 p t •span 60 1 p t .T w e e n 6 o 3 pte.bpanl40 1 pt.TveenfcO eee ♦♦ •4 15 minutes 30 n i n u t r s 30 m i n u t e s 60 m i n u t e s 60 m i n u t e s S p a n *40 1 pt* S p a n *40 i 1 pt. 3 p t e . Tween *40 1 i 1 pt .Tween *40 ♦ 48 It was apparent from some of the experimental work done in the la''s’T.torv that the type of water was a factor in the stability of enulslcr.r. ly Tftp water, distilled water and lake wrter shown by early tests. did not react uniform­ Table 7TTT indicates the results of experi­ mental work using both a balanced and a slightly heavier than balanced -ixture of xylere-trichlorber.nene with Tween 60 as emulsifier. k r : of emulsifier were us^d per 30 ml. of mixture. Six Here again. 10 ml. of the mixture was shaken with 9 0 nl» of water and the amount of rr111 in ~ was observed hourly. The reading® re; recent the average of rlx triple st ro:n tcr\pr"lure. It will be seen from Table TTTT that differences appear to be grer.t"t b.etwner the tep and. water scries when balanced mixtures were lr. view of these differences, only lake water (from Lake Lansing) 'me utilised ir, subsequent laboratory investigations of balanced mix­ tures , except where otherwise noted. .1 field trial, June 18 v«s designed to compare the effects of a balanced mixture of orthodichlorbenzene-xylene (is2 ) and one of trichiorb^r.rone-xylene (is?). At this time of year mb jut one and one-half to two feet in height. Chara at Lake Lansing was The applications were ■rir by means of the power sprayer and were at the rate cf 135 gallons p- ncrr using two percent sulfonated castor oil as emulsifier. In crier to obtain some idee of the density of the ctand of Chara, the rcceodptre es outlined by "Pall (?) was followed. The average weight of Chara with six casts of the hook was 1?»? ounces with a range of 12 to 17* At the time of the next examination, eight days after treatment. XABLX Till X3T3CT QT TTPE <37 WATI-2 OW STABILITY 07 JKULSIOHS ITSINO TWEET 60 AS JKULSI7IER . Typ« of v.'ater TrlohlorbenseneXgrlene Batlo Anount of Settling 1 hour 2 hours (In nl.) 3 hours 4 hours 1(2.5 4.6 10.3 10.9 13.8 1*3 3.3 8.5 9.2 11.2 1(2.5 3.9 7.9 9.1 10.8 1*3 2.1 4.1 4.9 6.6 1(2.5 4.5 8.0 10.0 13.5 1*3 2.3 *.3 5.2 6.6 Tan 31atllled Lake *9 th^re vere indications that the application!! had been fairly successful. Where there vere no other weeds, Chara vas dovn and on the bottoa and it vp« very eaey to obtain an oarful of the brittle and bleached plants. Vhere several plants of Potaaoaeton anpllfollus vere growing, the Chara appeared to drape over then. Periodic observations vere aade the rest of the stumer on these plotr and nowhere did the Chara aake re growth, a lev pxants of Potamo- geton agnlifoliub persisted throughout the ranoner. Likewise a few plant? of Wrriouhrlltm vert Iclllatup continued growth, although it may hftrr been that these drifted in following the decline of the Chara. Toward the end of the season , several Ekaan dredge samples taken and in them were recognisable Chara fragaents. vere Ho evidence of regrowth of the algae was to be found. The Chara mat in pond No. 10 at the Hastings Pish Hatchery was about 1? inches thick and extended to within 6 inches of the surface. The uniformity of this stand , by June 21, 1950, made it ideal as a testing ground. The materials and rates of application are given as follows* Mixture Batlo Amyl acetatedlchiorp entanes Xylene—ortnodlchlorbensene Xy! ene-triehlorbenzene 2 j1 Gallons ner acre Emulsifier 255.7 Mulsor Y? 255-7 Tween 60 255.7 Tween 6c The emulsified material in the amyl acetate-dichloropentene and xyler-e-orthodichlorobensene plots stayed up exceptionally veil. Tlve 50 or sir hours later a whitened patch vas evident about each stake. In every plot* ten days later, the upper 5 to 6 inches of Chara v'"'« bleached and disintegrating (Tig. 1*0 but the lower 12 inches v**~e normal (Tig. 15) • ^h® emulsion caused the killing of Chara for r depth to £ inches and did not penetrate further. One ron*-h after treatment, the plots still stood out In sharp contrnpt to the surrounding area. The upper layer of Chara was well disin- -rated and fell apart wher. touched with an oar. In none plots the green Chara underneath was beginning* to push up through the debris. Tron the results of this series of ap-liceticnr it was apparent t'-.n+ when the Chara war dense, the emulsion of a balanced mixture would r . 4- p e n e t r r t e r-ore than the top few inches. Here the emulsion remained end e f f ected a good kill. The next proeeedure was -to so weight the mixtures that they might penetret* further into the Chara and affect a greater extent of kill. In an effort to secure penetrrtion, a number of mixtures having different specific gravities were made and applied. rr iior used were as follows: Mixture Ratio Tr Ichlorber.zer. e-xylene 1:2 Trichlorbenzene-xylene 1:2.5 Tri chi orber.ze me—xylene 1:3 Orthodichlorbenzer.e-xyler.e 1:1 Orthodlchlorbenzene—xylene 1:1*5 Orthcdi chi orber.zene-xylene 1:2 'Hie mixtures and 51 The emulsifier need was Tween 60 and the applications were made at "hr rote of 255-7 gallons per acre on July 21. -*7*'’pnr series, the ratio In the triehlorbensene- 1*3 represents a balanced mixture, wheras the ’s? is heaviest and the 1 *2 . 5 intermediate. Two weeVr after trentnent, all the plots appeared to be about the ■mp. thr>t is the top few inches consisted of bleached and brittle C'-'.r.yr-, while beneeth this the plants were normal. There appeared to be r?*[f-<*cronee in the depth of penetration between any mixtures as evi'ence^ bp mee.mrerert p of the top and bottom portions. TTo further effort^ to weight the mixturep were made as the purpose of balancing is thus defeated and the emulsion does not Ion*- persist. At Portage Cree^ Trout Pond, three applice.tions were nede with the tri c M orbensene-xylene mixture. The first was made July ?, 1950» o v r arer "I—P" (Ti*-. 1 6 ) and at the rats of 120 gallons per acre the I :*5 ratio ar.d sulf'-nrted castor oil to the extent of two percent. Thr area consisted entirely of Ohara vdiich had not been affected by treatments of dr?' herbicides made when the pond had been ■'-eined the previous winter. Three wee’-s after trertr.ent. it arueered that the control of Chara, er-ecially in the shallow water, hpd been vory g-od. Ir-'ts were or the bottom and diVnterretinr. tir^actory in water more than two feet dee-->. "re«s.were the weeds down Results were not as sa— Here, only in certain while in other areas t~> support n layer of deed Chara. In this area the normal olants seemed This condition existed for the re­ mainder of the season, the shallow areas remained clear and the deeper °roe® were spotty. 52 Treatments of the remaining two plots were nnde July 31 using: 1 :? ratios of the trichlorbenzene-xylene mixture at rates of 1 2 2 .h and !-c.2 gall one per acre. Chara predominated in “both plots with plants of ?ctanop;eton natans and Ceratonhvl 1-uy demereuin less abundant. M.-;-. ■-'f these treated areas is given in Fig. 16 Loca- where area •,9'' was *rented at the low concentration and area *1 2 fl at the high. These plots were next examined three veehe later. concentration, very good control of Chara was obtained. u-. the bottom and were disintegret.ing. Even at the low The plants were Potanofreton natane arpesred to '-vr v rrn injured, as shown by the fact thet. most of the floatin'* leaves re der.d and of 4 f light-brown color. Each plant, however, was observed ^eve at least one or two green leeves. The .resence of these leaves !ndic"ted unsetirfactory control of this euecies. The effects in the plot which had received the greater concentration vere similar to those of the lower. C era t o mhyl1nr. demcrsun and Chara were disinte.-ratin.- on the bottom, three weehs 8fter trertner.t. The treatment a reared most successful in water one and one-half feet deer, "Ithough satisfactory control was obtained in veter up to two and onehnlf feet deep. Potano/reton natane responded ir. much the same way as it had at the lover concentration. Although an earlier trial at Lahe Lane in.- had failed to reveal any difference in effectiveness between xylere-trichlorberzene and xylenerthodichlcrbencene, another set of applications vrere made July lh. at the rate of 95.6 gallons per acre to see if lover dosages would shew a difference. These applications were made at Hastings. pond TTo. If, ^'here a heavy stand of Chara was very uniform over the two plots. A wee’- followir.r the application it was observed thrt the tore of 53 the Chara plant* vere killed In both areas vere still green. Three weeks later while underneath the plants the areas in the shallow eater of "both plots seemed to show the hest control. Here portions of hoth plots were clear, Chara haring fallen to the bottom and only stubs and debris were left. A visual examination indicated a greater degree of control in the trichlorbenzene-xylene plot than in the other. Chara. nine weeks after treatment, in areas where Just the upper ortions had been killed, had resumed growth but did not make a re, appearance in the shallow areas where it had been effectively controlled earlier in the summer. On the 2Mth. of June a balanced mixture of orthodichlorbenzene- xylene, with Tveen 60 as an emulsifier, was applied at the rate of 200 r-al1ons per acre on Heteranthera dubla and Mvrloohyllun vert iclllatum. This application killed the weeds to the roots so that nothing remained on the bottom but pieces of dead stems. Another application made a week later on the same species, but at n. cjncentration of 67 gallons per acre, did not give a satisfactory control. acre Heither did an application at the rate of 127 gallons per made July $th. give more than Just temporary control. Other applications made on Chara with the balanced mixture of trichlorbenzene—3^'lene, in mid-July and early August, at rates of 70 to 127 gallons per acre, did not give as satisfactory control as did early season applications. In an effort to effect a kill of the lower portions of a dense patch of Heteranthera dubla by making the mixtures heavier than g 5* "balanced one, a series of three treatments were made Angust hth. using trichlorbensene-ocylene at ratios of 1*2, 1*2.5 and 1*3 at concentrations of 12? gallons per acre with Tween 60 as the emulsifier. There Aid not a , ear to be a better kill of the upper portions of fl*+-****p.thera Aubla than the lower vhen the 1*3 ratio was used nor a better kill of the lower norl-uns than the upper portions vhen the 1*2 ratio vas used. Other applications on Heteranthera dubia were made at concentrations rar..-ing from 7 5 to 1 ? 2 gallons per acre. At the hitler concentration, regrowth from injured plants was retarded for a longer period of time thar. at the lovrer, but satisfactory control vas not obtained. Two applications of the balanced mixture were made on Tallisnerla anericana in mid- and late-August. These were at rates of 127 gallons per acre using Tween 60 and Antarax A-AOO, respectively, as emulsifiers. In both cases control vas complete and in two weeks time only a very snail amount of debris remained to indicate the presence of the weed specier. Two experimental sprayings were made September 2 hth. on a dense star.-i of Xlodea which came almost to the surface in 3 6 inches of water. Trichlorbenzene-xylene mixtures were again used at the rate of 128 gallons per store. These mixtures instead of being in the ratio of 1*3 vere combined so as to be heavier than balanced mixtures and to have rpec'.fic gravities of 1.05 and 1.1 Althou^i the mixtures did not emulsify very well, this poor enmleification apparently had little effect on the results since three weeks later, the treatments were very effective, even over a larger area than where the mixtures had been applied. The bottom in both plots vas clear of live Anacharls canadensis and only debris re_ 55 2 ,i*-D FILLETS In September of 19^*9 obtained. experimental samples of 2,^-D pellets were Their composition was as follows: Tvnnjhwy Ingredients and concentration per 100 l b . H-9123 9«1 pounds 2 , Ur-D and 72.8 pounds HaPCP H-9125 h. pounds 2, U—D H-9126 h. pounds 2, U ,5— 1 It was intended thet these pellets would he broadcasted ower the surface of the water, sink and settle Into the bottom. compounded as to go slowly into solution. They were so Once on the bottom they would slowly liberate the active ingredients which, it was hoped, would be absorbed by the roots and thus exert a toxic influence on the plants. It was proposed that the three samples of pellets be put out in the fall in order that they should slowly dissolve during the winter and the active ingredients be absorbed or otherwise contact the rest­ ing portions of the weed plants. One of these of the first Indications of the effectiveness of at least one compounds appeared after the 2,h-D-PCP applied at the rate of U26 pounds per acre. pellets hadbeen This was scattered over a plot of soft-stem bulrush, Seirans valldus. which was growing in shallow (*4 inch) water on sandy bottom. September 2nd. The date of application was A week after application, the bulrush leaves had turned 56 a light tan to a whitish yellow eolor and were beginning to lodge. Two weeks after application, the ‘boundary of the plot was clearly defined as the green, normal leaves outside the area stood out in sharp con­ trast to the burned, lodged leares within the plot. der of the season, further disintegration and deoay During the remain­ were observed. Underground rootstocks did not hare the normal appearance nor turgidlty that those had outside the area. The south end of pond No. 10 at the Hastings Tlsh Hatchery laid out in square-rod plots. was By putting in stakes and making a grid pattern, plots were laid out in the fall of 1 9 ^ 9 &nd trep.ted (Table IX). A fairly uniform depth of water, about two and three quarters to three feet, was obtained by keeping away from the edges of the pond. vere not at their stage of most vigorous growth. Chara. Anacharls canadensis and attention was given these plots The weeds The main species were flAbellarls. Ho further following application of the pellets until the following March. On March 15, 1950» holes were chop, ed through the ice in the center of each plot which had been treeted os follows: Pounds £er acre Material Plant species 6.U 2,U -D Ranunculus flabellarls 19.2 2,h-D Chare. Potaaogeton flllformls 19.2 2 ,h ,5-T Anacharls canadensis 3.2 2, h—D-PCP Anacharls canadensis 320.0 PCP Anacharls canadensis 800.0 Sodium borate Anacharls canadensis 1600.0 Sodium borate Anacharls oanadenels TABLE IX RESULTS OT SPRXSG XZAHIXATXQHS 01* XALL TREATED FLOTS Material 2,4-D-PCP Bate par acre (In pounds) .63 1.27 Result* Sa^o ponflwoed almost to eurfaoe I | Elodea growing well I 1.9 Water-crovfoot dense and growing well 3.18 Mod plantain growing up well 1 3.2 19.^ 2,^+-D 2,^.5-T Cheok | Soft-stem bulrush retarded Evidence of new El odea growth 6.J* Water-crovfoot dense and growing well 12.8 Scattered Chara plants 19.2 Sago pondweed dense and almost to eurfaoe 3.1 Wat er-crovfoot growing up to surface h.8 Chara a solid mat 800. Sago pondweed dense and almost to surface Evidence of new Elodea growth . Vater-orowfoot almost to surfaoe . Soattered Elodea and Chara 1600 POP Water milfoil to surface over whole plot 3.1 19.2 Sodium 'borate 1 160 Elodea at least a foot high with lime precipitated on the leaves 57 A rake wR« lowered through the hole and several samples of the bottom material were brought up and onto the surface of the ice. At thin examination, some apparent differences were noted between plots. In the plots where 2,4-1), 2,4,5-T and sodium borate, at the rate ■:t pounds per acre had been applied, the weeds appeared to be It was not -uncommon to brinr up a rakeful of mud alone without nr.y weeds or there would be Included pieces of dead plant debris. spri'-s wore not common. Qreen Those sprigs that were collected, were placed ’r. .’arc and, after several daps in the laboratory, showed signs of - m o w e d growth. On the bottom of the plot which had received 2,4-D-PCF, the debris )f Chara could easily be seen extending upward several inches from the bottom. With a rake it was possible to obtain a rakeful of the debris. So t * jf th ?e ve.p obviously deed but n considerable portion of it looked c tb.urh it mi -hi grow ;-rovth of portions brought back to the lab oretor**, verified the observation). Included in the rakefulTs of Chara ’ebris were green sprigs of Anach.erLr car.nl ensls. In the p l o t which had been treated with PC?, approximately the sane condition existed as that in the r ran tree ted with 2,4-2-£>CP. Anacharls canadensis.in the plot treated vith 1^90 pounds of rod.i*r-. borate, was conspicuous and a rakefu! could be gathered with. Tittle difficulty. Approximately one-fourth, of the plants in a rakeful a :cured to be in a normal oondition and able to resume growth when cinditionr were again favorable. In every plot there were plants in various stages of greenness. The plots were again examined or. May I*5 and on May 29. Results 58 of these observations are presented in Table IX and indicate regrowth in nxeTzr plot. On September 23. 1940, * square—rod plot was staked out in shallow water in which Iftruha latifolia and a sedge were present. This v/ar on rauclsy bottom at the south end of pond No. 12 at Hastings. Treat- nent, consisted of 2,4—D-PCP pellets at the rate of 3.18 pounds 2,4—D per acre. This treatment an .arently had no effect during the winter for the following spring the cattails again came in to re-populete the plot. On October 2 and 12 sever, applications vrere made in water about three feet deep at Lake Lansing. The weeds consisted of a well mixed stand of Chare. Potamogeton ar. Ilfollus. P. sosteriformis and Valllsnerla anericana. The materials used and the rates of application were as follows: let .-rial Rate per sere Cin rounds ) 2,4-L 2.4-2 8.6 2,4-D 12.5 2,4-r 17.* 2.4.5-T 8.6 2 .4.5-T 12.5 V/hen the plot" were next examined. June lc , 195r'» r-° noticerble d'ffererce could >c observed- between tree ted and untreated plots. During the remainder of the summer, growth of a’ 1 species continued rr.d no v*'*e .ce 'f control developed. 59 At Hastings, in the north end of pond Ho. 11, an area was located vhich contained SSflftfllBEll geteranthera dubla. An appli­ es* ion of 2,4—D pellets was made 8eptemiber 30th. at the rate of four pounds per acre. Examination the following year failed to rereal any signs that control had been effected. At Hess LAke two large plots were located in the shallow water. The;- contained mainly Chara, Valllsnerla amer 1cana and Potamogeton aarpllfolius. On October 1, 19*»9. 2,^4—D pellets were distributed over one plot at the rate of h.8 pounds per acre and 2,Af5-T at the same rate orer the other plot. In late April of 1950. the time of the next examination, it ap eared as though Potamogeton amollfollus had been affected by the treat­ ments as in both of the plots there was debris of this species present hut no living portions. Chara appeared unaffected and continued to grow throughout the ensuing summer. Valllsnerla amer 1cana and Potamogeton am ;llfollus later appeared and their growth continued during the summer, tfo difference could be observed between the treated plots or between them and adjoining, untreated plots. About 75 yards offshore , was a very uniform stand of Potamogeton aar.lifollus and Chara. the latter almost completely cowering the bottom with the former too numerous to run through with an outboard. area one-quarter acreplots werestaked plots were made on the same date half the concentrations. out. In this Treatments of these two as the above two applications but with Eight months later, an examination failed to reveal any signc of control. Chara was still quite uniform on the bottom. Potamogeton aamllfollus had cone to the surface and was in flower. During the remainder of the summer there appeared to be no decrease in the plant 6o population of those two plots* Id the winter of 1950 an opportunity was found to apply treatments of dry herbicides on the bottom of a drained pond* The treatments were made on March 14 orer an area where Chara became abundant and objection­ able during the growing season. area "1-8", Fig. 16. The general location of the plots was In The materials and concentrations used were as follows: Hate uer acre (in pounds) 216 17a TCA 6.4 2.4-D 2,4-D-FCP 14.4 (2,4-D) and 116*5 (PCP) 120.0 17a PCP 28.8 (2,^-D) and 233.0 (PCP) 2,U-D-PCP Alpha hydroxy beta trichlorethyl sulfonic acid 128. Sodiun borate 480. Copper eulfate 638. The dry materials were distributed orer the frozen pond bottom by hAnd. A month later water was let in and cowered the treated plots. Stakes put in to limit the plot boundaries, remained conspicuous al­ though those in the deeper water were submerged. Three months after treatment, living plants were found in all the experimental plots. -arden ralce and for examination. dredge A were used to bring up plants and debris Approximately four months after treatment no difference could be seen between the treated plots. Chara formed a 61 practically uniform mat orer the 1)0(100 of the area. Since a preliminary field trial had indicated a possible difference in effectiveness between the samples of pellets, laboratory work was de­ clined to determine if these differences existed. Some Indication of the rapidity of toxic action that might be expected from future field trials and an idea of concentrations that might be required were also desired. In comparing these compounds, wide-mouthed one— gallon jars were Tised. Cuttings of plants were potted and allowed to remain in aquaria in the greenhouse until they were rooted and shoved evidence of the formation of new leaf tissue. These potted plants were then used in the Jar tests, results of which are given in Table X. In the late spring of 1950 of pellets were secured. additional samples of the three kinds These had much of the fine material removed so that they were not as dusty nor as disagreeable to handle as the previous samples. Nevertheless the 2, *4— D-PCP pellets, when handled, would usually initiate a cough. At Hess Lake thirteen treatments were made on June 1*4. were made on practically pure Chara uu about six inches. Seven whlcn, at this time of year, was The treatments were as follows: Materials Rate per acre (in pounds) 2,*4—D 32 2,h-D 6*4 2,**,5-T 32 2,4,5-T 6h TiJiLi X BESU1TS OF JAfl ?3STS WITH Sa-jaiME®LL PELLETS Potamogeton anplifolios 1'Aterlal H-9125 H-9123 Parts per nillion Anaoharls canadensis Days Effect Days .2 10 - 17 H .2 9 - .25 28 tft 28 ft .25 28 - 28 t .25 18 - 18 - •5 9 10 tt .5 28 - 28 - •5 25 0 25 t .02 17 ttt 17 .05 18 .1 18 .2 25 - Effect m 18 - 18 - 25 .2 B-912& Dovclds G 6 .25 18 .25 18 .5 6 .2 10 .2 17 .25 28 •5 6 .5 28 •1 18 .1 18 .2 17 .2 9 .25 18 - toad + still grtsn h m slight growth no control 62 (Continued) MM+rrat Bute T>er acre (in pounds) 2.4,5-* 128 2,4-D-PCP 72 (2,4-D) and 2,4-D-PCP 576 (PCP) 1244 (2,4-D) and 1152 (PCP) Bone of these treatments were effectire on either Chara of Potamopeton amollfollue since these species continued normal growth through­ out the summer. The remaining six plots were in shallow water from one and one-half to two and one-haif feet deep. The bottom was sand and the weeds were ‘'ran plants of Valllsnerla amer 1cana and Potamogeton amollfolius. Just outside the edges of the three innermost plots, two scuare-yard areas rere laid out by means of yardsticks and stakes. All the plants in these two areas were harvested and allowed to drain for two minutes on hardware ''loth after the loose sand, adhering to the roots, was shaken off. overage weight of the plants in these two areas was 15 grams. tended that later In the summer vrlthln the treated plots The It was In­ plants in square-yerd sample areas would he removed and weighed. '•'f the effectiveness of the treatment could then he made. An estimation The treatments were as follows: Material Rate per acre (In pounds) 2,4-D 256 2,4,5-T 128 2,4-D-PCP 58 (2,4-D) and 498 (PCP) 2,4-D-PCP 174 (2,4-D) and 1598(PCP) 63 (Continued) Material late per acre (in pounds) 2,h-D-PCP 291 (2,h-J» and 2329 (PCP) 2,U-D-PCP 582 (2(h-D) and U658 (PCP) The pellets were distributed as evenly as possible fines of the plots which were approximately 8 x 8 feet. within the con­ Twenty minutes after applying 2 #h—D-PCP at the rate of 291 rounds per acre, there was noted a reddish color in the water. A somewhat less intense color was to he seen in the plots treated with the same material at a lower con­ centration. Two weeks later, it was very difficult to see any difference be­ tween the plots. Howerer. ei£it and one-half weeks after treatment, it was observed that the weeds were not as conspicuous in the areas treated with 2,h-D-POP at 17** and 291 pounds than they were where treated with 58*0 pounds per acre. The plants had apparently fragmented as a result of these high concentrations but an occasional green plant portion was found. Twelve weeks after treatment, there was nothing to wei^i in the area which had received the greatest concentration of 2, h-D-PCP. The few weeds left in the two plots which had received lees than this amount, were too thin to count or weigh. Two scuare-yard samples were taken in the plot treated with the least amount of 2»h-D-PCP and the average of these was 12 ounees. Sample w a i s t s were not taken in the areas treated with 2.^-D and 2,h.5-T primarily due to the depth of the water and because it was so obvious that they supported more 64 lants then did the sampled plot. *>82 pounds per acre. ■■'lot 2,4—D-PCP gave complete contTol at The line separating the 2,4-D from the 2,4-D-PCP \»s very distinct. On Jane 17 three adjoining plots, each about one-fourth square rod In area, were laid out on cattails and the following treatments were made: Material 2,4-D -per acre (in pounds) Phenol per acre (in pounds) ?.,4-D-PCP 174.72 1397.76 2.4-D-PCP 291.20 2329.60 2.4—D-PCP 582.40 4659.20 Shortly after the applications v;ere hawing some effect. scorched. It was apparent that the treatments The sedges and cattails were browned as If Pellets, which had accidentally fallen along the margin of the areas, left distinct brown spots In the sod. treatment therewere only Five weeks after ninecattail plants alive in had received the greatest amount ofpellets. the area which In the other twoplots it was estimated that there was less than ten percent regrowth. This regrowth continued to grow during the remainder of the season. On July 22, 2,4-D-PCP pellets were distributed at the rate of 128 pounds per acre in water less than two feet deep where Heteranthere dub la and Myrlonhyllum vertlclllatum were growing on the sandy bottom. When the plot was next examined, three weeks later, the treatment appeared to have been effective. The weeds were down on the bottom and no live roots or stems could be seen. and flaccid. Plants were slightly slippery The few Anacharls canadensis and Ceratoohyllum flyntrmg 65 plan** that were in the plot were leafless. Portions of the bottom were olear of plant material. Tour weeks after treatment, farther dieIntegration of Seteranthere dubla was noted In the shallow water. Another area was treated at the rate of 291.2 pounds 2,4-D and ??29 pounds of phenol per acre. This was on a mucky bottom where Potaoogetos perfollatuB. Heteranthera dubla and Anacharls canadensis were growing. Some of the pellets, although in an advanced stage of r.olution, were still recognizable four weeks after treatment. weeds were flaccid, covered with marl and appeared dead. The There was an occasional green shoot on the bottom in water less than a foot deep. Nine weeks after treatment, the bottom was open, debris of Heteranthera dubin was conspicuous but no new 6hoots were to be found. effected by the treatment The area seemed to be slightly larger than the area over which the pellets were applied. An area of about a square rod of soft-stern bulrush, Sc irons valldus. growing in the shallow water of pond Ho. 1 at Hastings, was divided into two parts and one of these was treated July 22 with the 2,h-D-PCP pellets at the rate of 145 pounds 2,4-D and 2328 pounds phenol per acre. Six days after treatment, the leaves leaned over as if hit by a heavy rain. Thirteen days later they leaned further and were bleached to a light yellow color. There was an odor of PCP in the vicinity and an evidence of the former existence of the pellets could be seen on the bottom. Two months after treatment, there were only a few stubs of leaves up to Indicate where the plot had been (Pig. 17 and 18). sticking The matted roots in the treated area did not appear normal as did those of the untreated area. 66 Two adjoining plot® were staked out orer bulrush on July 22. One plot was treated with 2,4-D-PCP at the rate of 129.2 pounds 2,4-D per acre, the other at twice this rate. In the natter of a few days* all the leaves in both plots were bleached and leaning. Six weeks later there was no sign of regrowth in the plot which had received the pellets at the hl^i rate of application. The bases of some of the bleached leaves in the other plot were still green and there were four,new leaves that were just breaking above the surface in the square-rod -1ot. On June 17 three,one-half square-rod plots were cut out of a uniform stand of narrow-leaved cattails. hut no standing water was present. The soil was water-logged Treatments were made with the ?,£|-D pellets at rates of 28, 48 and 96 pounds 2,4-D per acre. These treatments were not effective. A series of three,one-half square-rod plots of cattails were cut out of a uniform stand with a passage way between each plot to facilitate distribution of pellets and subsequent examination. The a ' licrtlons were made June 17 at rates of 38.4, 64.0 and 128.0 pcunds 2,4,5-T per acre. Five weeks later, no difference could be seen between the treated plots and the untreated. An examination later in the season failed to reveal any evidence of herbicidal action. normal. The basal portions were turgid and the rhisones appeared 6? Translocated Herbicides Tmha Applications of less than two pounds per acre of the isopropyl ester of 2,4-D as an aqueous spray, produced a mottling of the leaves of cattail, Truha latlfolla. and a browning of the tips. The lover por­ tion". remained green and the centers continued growth. During June and July of the first season of experimental vorh, applications of two scurf's and at rates up to 4.5 pounds per acre, did not give satisfactory control. An application made late in the summer, August 5 as an oil «v,rny at the rate of 2.75 pounds per acre, shoved an apparently better control than did any previous treatment. Therefore, many subsequent a." 'Mentions of the ester form of 2,4-D were ap-lied as oil sprays. Only a few applications were made durinr the 1949 and 1950 seasons. Durinr the 10^9 season, best results were obtained when two successive r plications were made at a six veel: interval. Tune 20 when the regrowth was veil established. One plot was re-sprayed As a consequence of the second spraying regrowth, from the merietematic region, did not begin to appear until late August. Evidently the little regrowth nr.de subsequent to that time, enabled the plant to store up enough food so thet the following season some 'le.nts did reappear in the plot r-1though there were fever than *n adjoining, untreated plots. The butyl ester formulation did not show any apparent superiority over the isopropyl ester for controlling cattail even when used at the rate of 6.5 pounds 2,4-D per acre. Hates as high es five and six r>ounds per *cre of the isopropyl eater of 2,4,5-T did not prevent re growth. Sorer*! applications of less than these amounts were made hut they only succeeded in slightly rusting the foliage. This species appears to he quite tolerant to hoth 2 ,4-D -ncl 2 ,^.5-T. In order to obtain some idea of the cottparatlre effectiveness of the free acid and two 2,4-D formulations (ester and amine) , three ad­ joining plots were staked out. Square-yard sample counts of plants were taken to obtain an estimate of the density of the cattails. The treat- r^r.tr were applied June 17, 1950, at the rate of 3 pounds 2,^-D per acre. The free acid was dissolved in trlhutylphosphate and all three spray boIu tior.s were ap lied as oil sprays. In every plot, six days after the applications, effects of the treat r.er.ts were noticeable. Eleven days after treatment, the upper third of the leaves of plants, where the acid had been used, became browned and were so dry that they had fallen over. The plants in the other plots wcr^ considerably browned and showed some lodging. This browned appear­ ance, upcn closer examination, was seen to be due to numerous spots, closely arranged upon the leaver so thet from a distance, the entire upper portions of the leaves appeared brown. The lover portions of most leaves were still green and apparently had not been contacted by the spray. The bases of other plants were not turgid and when these slants were pulled or separated at the growing point, there was a smell of oil and a slippery feel to the meri stematic tissues. Apparently the oil had moved down the leaves to this growing point. The plants in the acid-treated plot, three and one-half weeks after treatment, appeared to be sli^itly more affected than the others in that 69 more of the plant* were prostrate* Regrowth was observed In all plots* All three were again sprayed on July 11 at the same concentration. Ter days after re-treatment, there was still considerable green showing In the amine-treated plot. More of the plants in the ester-treated plot P ’reared to be down than in the other plots, but all showed new growth fcir weeks after re-treatment* canted. At this tine sacple areas were again The treatments, together with before and after counts, are riven in Table XI* TABLE XT cctapi sor or tct effectiveness of acif. isotrgpyl fcter act amiste SALT CF 2,h-»0N CATTAIL, TYPHA LA TI FOLIA, SHOWIITG THE AVERAGE !TTJM?ER OF PLATT? £ PER SHEARS YAPP ACT THE PERCEPT REFTTCTIOTT Material Before Trer tnent Percent Reduction Regrowth e 0 id lc 72. 1.7 1rc■■rc',''.'l ester 17 VA. 1.0 P"*riP ralt 11 5*. 2.7 15 0. e .r.trol • "a -1tt aria Or: July 20, 1?**S, the isopropyl ester of 2,fc-L was applied to a plot arrowhead, Saaittaria latifolla. and cattail, T m h a latifolla, at the rrte O f 2 . 7 3 pounds 2,i;-L per acre. Six days later the cattails showed M t t l e injury but at least 60 percent of the arrowhead leaves were twisted "•'d "browned. Eleven days after spraying, all that remained of the arrow- 70 heal plants were brown, crisp leaves. Three weeks after treatment, the c ^r.t.rol appeared to have “been very good ae there wee lee* than ten per­ cent regrowth. ®ie year following, however, hoth specie* resumed growth An arrowhead plot, which had "been sprayed the year previously with TCA ana was regrown, was sprayed July 12, 1949, with 2,4-D at the rate of 2.7P pounds per acre. Tour weeks later the application appeared to h*ve been successful as there were no living arrowhead leaves in the ;lot and some of the rootstocks were decaying. On August 8, 1949, two square-rod plots of arrowhead were sprayed with the isopropyl ester of 2,4-D at the rate of 2«7? pounds 2,4-D per acre. One application was made as an oil spray vher&s an aqueous spray war used in the other. Sis days later plants, in the plot which had been treated with the ^queoup spray of 2,4-D, were down and showed typical twisting of petioler. Two weeks after treatment, the old leaves were dead and decay­ ing but new leaves were conspicuous. The bases of the old leaves were lead but the rootrtocks were alive and remained so for the rest of the rerson. The area never took on the appearance of untreated, adjoining areas (Tig. 19) . although 4 or 5 »®w shoot? per square yard made good -rovth. The effects on the plant? in the plot where 2,4-D in oil hed been use! used. followed rather closely those where an aqueous 2,4-D spray was It would be expected that the addition of the oil would acceler­ ate the effects of the 2,4-D treatment. In this case the reverse apoeer ed to occur as the weeds In the plot which had been treated with an aque cu' jrp.y, were orostrate before those in the oil-treated plot. In both 71 -nrer, however, a satisfactory- control was obtained. With the adrent of the 1950 season. It appeared that a radical ^nnn,*e had taken place orer the area eorered by the plots. Water hem­ lock had inraded this area and only a few arrowhead plants were left to ’rdic'te the previous existence of this species. This growth of water Ar-lock was sprayed at the approximate rate of three pounds 2,4—D per 'ere on August 21. Three and one»balf weeks later, hardly a trace of the plants remained. Water hemlock is rery susceptible to 2,4-D. The only effect of the treatment of arrowhead with applications the isopropyl ester of 2,4,5-T at rates of one and two pottnds per 'ore, made July 20, was a slight crinklinr of the leaves. A few leares ’Id dry up but the majority, although distorted, maintained their po­ rtions in the plot. Later there were signs of regrowth. An aTjplication of three pounds per acre was made on August 9« ’ays later Wine some leaves were brown, some yellow and others were inverted. Although there was considerable evidence of injury, new growth began to ->ear through the dried leaves by August 25. When 2,4-D and 2,4,5-T were compared for their effectiveness on arrowhead, 2,4-D appeared to be superior. Pontcderla At the beginning of this investigation pickerelweed, Pontederia cordata, was sprayed witii light applieations of the isopropyl ester of ",4-D. On July 22, 1948, an application was made at the rate of 2.09 r-’indn 2,4-D per acre. A week later, the leaves were twisted as is 72 typical of 2,^-D injury to broadleaved plants. Other leaves and their •~etiolee were on the surface of the water and some were leaning on one encther and looked a« though they had heen hit "by a heavy rain. With­ in thirty days, new leaves were appearing at the surface throughout the sprayed area. At Lake Lansing an Isolated petch of plckerelweed, approximately c-><» sruare-rod in area., was enrayed on July 26. 19*^, at the rate of rounds 2,h-L per acre. Five days later ahout five percent of leaves and petioles had pulled loose and were floating on the surf^ec. The remaining leaves pulled easily. petiole to separate from the rhizome. A slirht tug caused the Pulllnr on the petioles of un­ treated plants generally caused the petioles to break at some distance above the point of attachment to the rhizome. tire plot were pulled by hand at this time. The leaves In the en­ This was done In order to test the theory th~t the scars made by the separated petioles, would become a focus of bacterial infection which might lead to decay of the rhizome. At the time of the next examination, nine days after pullln**, the bottom of this area was conspicuous with deed petioles end no new leaves were to be seen. later, although perte of the root­ stocks appeared to be In an advancedsteae of decay, there were por­ tions which were obviously not dead. On Jhly 1, 19*49, the lsopropyl ester of 2,*4-D at the rate of three pounds per acre, was ap 'lied, to a plot consisting mainly of -Ickerelweed. Ten days later, the leaves were brown, they were easy to pull, the bases ware soft and they smelled of decay. Hone of the 73 leaves had self-pruned, that is, none had separated from the rhisome. Sixteen days later, a few new olokerelweed leaves had appeared above the surface. The bases of the petioles of these were soft, smelled of decay and palled very easily. Pickerelweed oetioles, four weeks nfter treatment, still palled easily and no regrowth was evident in tnr center of the square rod plot. By September 15,one and one-half northr after treatment, the plot was bare when compared to untreated "t o p .r. Approximately twenty leaves of nlclcerelweed were all that showed above the surface. Petioles and leaves were decaying beneath the sur­ face. An emulsion consisting of the isopropyl ester of 2,h-D plus fuel oil, water and an enulsifyin°* agent, was an lied on July 11, 19^9, "it the rate of 2.5 pounds per acre. leaves pulled very easily. the surface at this time. Pive days after treatment, the A few new leaves were Just appearing above A month later, the leaves, which had been hit with the spray, were either lodged or had self-pruned and were floating on the surface. Regrowth war evident so that the treatment was not con­ sidered satisfactory. From these observation r it any,eared that re growth would occur if pickerelweed was sprayed with concentrations less than 2.5 :oun&s 2,h-D per acre. Another square-rod plot was sprayed on the sane day, July 11, at the r-te of four -ounds 2 , h - D per acre, new lerves wnioh had appeared. four days later there were a few However, some of these pulled easily. Sir. weeks after treatment, approximately twenty-five new leaves could be observed in the square-rod plot, lhe old leaves were dried and 74 shrivelled hut they remained uprl^xt. On September 15. more than two months after spraying, regrovth was very slight and the dry petioles were fallen orer so that the plot had an open appearance in oontrast to adjoining, untreated areas, When oil was used as a carrier for 2.U-D instead of water, it appeared to do a better job of softening the lower end of the petiole. With low rateB of applications, new leaves would frequently appear above the surface a month after treatment. By the end of the growing season, the plot would be just as dense as the adjoining, untreated plots. Several sprayings were made during the summer of 1950 in order to secure numerical data with which to compare the effectiveness of variour, fonnuletions. On June 26 the isopropyl ester of 2,4-D was applied on pickerelweed at the rate of 3»^° pounds per acre. Examination, twelve days later, showed that the treatment bad not been very effective. leaves were darkened, blotched, and. hung down Some but there were many new loaveo pushing their way up through the surface of the water. In con- rriron, an average of 6.5 lervec per sc.uare foot were found within the plot, while untreated areas had an average of 19.6 leaves. ber 6 By Septem­ the plot was filling with the new leaves, althou^i it was still considerably thinner than adjoining, untreated areas. Another square-rod plot was sprayed at the rete of 3.48 pounds 2,4-D per acre on June 26. turgor. 7our days later the leaves had lost their Twelve days after treatment, some bulrushes, which were in the mlot, were bleached almost to the water surface. They pulled fairly easily but the meristematic sone did not show any obvious sign of de— 75 cay. The pickerel weed leaves bed beooat dark-streaked or blotched* counts were made on August 2* per se/iare foot The treated area had an average of eight wheras the cheeks averaged fourteen* The new leaves, which were counted, were large and were in an upright position* hare patches Leaf In the old, dead leares were entirely browned and leaned almost to the water surface* Although there was a layer of algae over the plot, the general impression was that control had not been too satisfactory. Seven weeks later, another application was made at the same rate. This a;plication was very effective as shortly afterward, very few leaves a;’ eared above the surface and the old, dry, dead ones leaned over and lr,ter decayed in the water. Tour weeks after the re-treatment, the plot had an open appearance; algae covered the surface wheras in adjoining areas algae among the there was little or no leeves were trying to penetrate the algal hit by the lost spraying were to lean. mat twisted and the petioles. Sight new at tills time.The leaver* petioles werebeginning Here again, it appeared that one June spraying at three pounds 2,4~D per acre was less effective than two sprayings at Intervals of about two months. The butyl ester of 2,4-D appeared to be equally as effective on plckerelweed as the isopropyl ester formulation. Early in the investi­ gation, both formulations were used but it soon became apparent that one was as effective as the other when used at similar concentrations. A light application of the isopropyl ester of 2,4,5-T at the rate of 1.39 pounds per acre, was applied July 30 to a plot of pickerelweed. The immediate effect was to cause the leaves to become inverted and to loce their turgor. They looked as though a light rain had beat on them. 76 Tour day* after spraying of the next week the leares were still green. In the eourse many petioles were seen to he leaning and approxi­ mately ten percent were down and horisontal with the surface. li^ty percent of the petioles were leaning or were prostrate, nineteen days nfter treatment. Most of the leares in the plot were prostrate after fire and one-half weeks hut there were new leares which were coming through the surface. These continued to appear throughout the rest of the season. A somewhat beerier application, twice the above, was applied on ■JuT v 2 6 to a plot of pickerel weed. Vrovnish-stroaked and were drooping. Two weekB later the lerves were All the leares were hrowned with no new leaves evident, three weeks after treatment. A regrowth hegan to apnear in September and dereloped to such an extent by the end of the season that the plot became almost as overgrown as adjoining rrenp. The following July 1, 19^9. the ester of 2,*»,5-T was applied to a plot of pickerel weed, Pontederla cordata. at the rate of 2.?8 pounds per acre. Ten days later, the leares were black-streaked but could not easily be pulled. Hew leaves protruded above the surface. The ■^ases of the injured leares did not hare an odor or other sign of decay, fifteen days after treatment, the old leares were dry and shrivelled. A new rrowth was developing at this time. At the rate of 2.78 pounds 2,h,5-T per acre, another application in an oil emulsion was applied July 1 at Lake Lansln/*. The sprayed leaves and petioles were browned and shrivelled, eleven days later. Hew leares had appeared above the surface and both these and the injured ones pulled 77 easily. There did not appear to he any oil or oily residue at the bases of th«* pulled petioles* The injured leares were browned to the water l»vel nnd, within sixteen days* the petioles pulled easily* »v-1--.<»',red normal except that a few had worm-like markings. The "bases Four weeks after treatment, about fifty percent of the pickerelweed leares In the lot vere /preen, the rest were dry and shrlrelled. Some of the regrowth ">'i?led eesily but the basal portions were not decayed nor stained. By the first week In August, fire weeks after treatment, regrovth was more ■’•-Vindent than at ft previous examination and by the end of August the me* eh wes as green as the untreated area. A hearier application at the rate of four pounds 2,^,5-T per acre a l l i e d In an oil emulsion, was made July 12. This application showed mur*h the same seouence of events as lighter applications, except that r^/rrovth did not develop as rapidly. On June 26. previous to the flowerim- of pickerelweed, the phenyl acetic acid-2,h-D formulation was applied at the rate of 2.65 pounds 2 , il-D per acre. This area also contained some bulrush, Selrnus ralldus and water shield, Brasenla schreberl. Water shield leares, two weeks later, were less numerous than In adjoining, untreated areas and they had what appeared to be small, brown-edged holes. Some leares had the characteristic brown or blackish blotches which are commonly ob­ served on other snecies as a result of 2,U—D applications. The bulrush leares were light brown down to the water level and pulled easily. The regrovtn, especially of pickerelweed, was such as to cause the plot ayein to be snrayed (July 1) at the same concentration. Two weeks later almost all the leares of bulrush and pickerelweed were brown. The bul­ 78 rush leaves were browned nil the way down to the root nnd pulled enelly. The b^ses of some of the leares smelled of decay. Pontederla leaves were shrivelled, the petioles pulled easily and very few new le«rep appeared above the surface. Petioles of water snleld were coiled an*’ ^ev leaves appeared at the surface. could be seen in various stages of decay. Beneath the surface, leaves Q,uite a few of the pickerel- weed leaves had separated from the basal meristen and were floating on thr surface, three weeks after the re-treatment. Pour weeks later, August 8, by actual count of several square-yard ar^as taken at random, there were but a third as many new leaves per square yard as there were de^d pickerelweed leaves protruding above the s'irfpce. This did not include the petioles of pickerelweed and the thin leaves of bulrush which had separated from the base and were floating on the sirface. A later application was made July 8 et the rate of 2.65 pounds 2,^-D per acre when an area of Pontederla cordata was in flower. Two weeks later it was noticed that the bases of the petioles were soft and were decaying. The leaves pulled very easily and practically all of the leaves had lost their turgor. Three and one-half weeks later an ex­ amination showed that a considerable number of the leaves and attached petioles had separated and were floating at the surface. The remainder '••ore completely browned and separated with but a slight pull. week In another more leaves had separated from the rootstock and were floating at the surface. A considerable number were decaying underneath the surface and there were no normal leaves in the center of the plot. The compari­ son between treated and un—treated plots is shown in lif. 21. There were 79 fifteen new leares whiah had appeared in the square-rod plot, six weeks rfter treatment. The old, "browned petioles eonld he observed beneath the clear surface. Sight and one—half weeks after treatment the center of the plot was free of leares. Around the edge new leares were pre­ sent due to the crowding in of growth from outside the treated area. flynphaea Early in this investigation, fairly low concentrations of the iso_vc_yl ester of 2,h_D were used on white water lily, Nyrrmhaee odor at a . On July 26, 19^*8. the ester form was applied at the rate of 1.39 pounds per acre. Regrowth occurred a short time after wards. On August 6 tv/ice this amount was applied per acre, as carrier. using fuel oil at the rate of 80 gallons This was sprayed on white water lily and yellow \-eter lily, Nunhar advena. Three days later, the petioles of both r: ecies were coiled and the leares, which had been hit by the spray, were undergoing decay. fron the root stock. In spite of this there was evidence of new growth Two weeks later, the coiled petioles were beneath the surface and the old leares were floating, inverted of the water or they were submerged. on the surface Although new leares were opening abore the surface, three weeks after treatment, the plot did not contain -s many leaves as adjoining, untreated areas. To see whether a high dosage would hare a more permanent effect, rn application was made, July 11, at the rate of 5*5 pounds 2,h-D per -ere. Observations made shortly after spraying showed responses similar to other early observations of 2.U-D injury. old leares were decaying at or Just below the surface. In 18 days, the The plot looked 80 mor*» open and new leaves vere not as much in evidence as in a similarly treated plot of Ifaphar odorata. The greatest effect appeared to he in tha -enter of the plot where several rhisones came almost to the surface of the water. Prior to spraying, this fact was not noted as the petioles '■’i" orted the leaves ahove the surface to form a uniform canopy. After the leaves had "been ’m o c ’ced down by the treatment, the proximity of the rhirones to the surface was apparent and it was in the region of there rMs'ries that the least amount of regrowth occurred. At tnis stage of the investigation it appeared that, although high Initial rates might be desired, repeated treatments seemed lilcely to be reg’ired. With this in mind a treatment at the rate of ?.h8 pounds per acre, using fuel oil as carrier, was made July 8 (Pig. 2?). inter the typical responses were very much in evidence. Two days The contacted vere inverted on coiled petioles and they were decaying. I- afterward Short— there were a dozen new leaves opening at the surface. Fifteen days after treatment, there vere more new leaves opening at the surface. The old leaves were decaying under the surface and the petiole? vere coiled and brittle (Tic. . An additional application was made on August 1? using fuel oil and the same 2,1«-D concentration. This appeared to be very effective since only a few green leaves appeared at the sur­ face. The lateness of the season may have had a bearing on the regrowth. Single, heavy applica.tions at the rate of ten pounds 2,^-D per acre, were tried on small scale plots during June and July but regrowth de­ veloped in every case. TTo apparent difference in effectiveness could be observed between the butyl ester and the leopropyl ester of 2,h-D when applied to ffywRhajga 81 odorsta. The first application using tha phenyl acetic acid-2,4-D formula­ tion on white water lily was made June 26, 1950» r t the rate of 2.65 pounds 2,4—1) per acre. Thia treatment was Twelve days later, the leaves that had "been hit with a sufficient amount of the spray, were decaying hnt new leaves were unfolding at the surface. nprey again at the same rate. It was then decided to Ten days after this re-treatment, the plot appeared open and a considerable amount of algae had come to the rurface. The difference between this and adjoin in/*, untreated plots wan ouite distinct. However, two weeks after the second spraying, there vrere a considerable number of new leaves in the center of the ■"ilot. The old leaves, which had been present at the second spraying, '■•rro dead, b r o w and disintegrating. Within four weeks following the second application, the surface was a solid rart of algae in which were floating small, new leaves of Wynrohaea odorata. Other leaves were un­ folding below the mat. Another solid met of white we ter lily leaves were sprayed June 26 Ft the rate of 2.65 pounds 2,4-E per acre (?ig. 25) • Effects from this licntion (Tig. 26) were similar to those of the other treatment. The surface, a month after treatment, again was covered with new leaves (FI*-. 27). At this time the plot was sprayed at the rate of 7*15 pounds 2,4-D per acre. Ten days later and decaying leaves. the olot. the surface was conspicuous with deed Algae now covered the decayed leaves and blanJcetted The surface of the water outside the plot still had white water lily leaves tightly packed together with little or no algae visi­ ble. Only four, s m l l leaves a-, eared in the center of the square-rod 82 olot. The leaves from outside the plot vere crowding in around the edges, but the eenter was clear. At the tine of the last Inspection, twenty- fire days after re-treatnent, algae covered the surface and there were '•’bout thirty snail, new leaves in the plot (Tig. 28). In order to observe the effects of a heavier Initial application. a ^Treatment was made, July 10 using the phenyl acetic ecld-2,4~D fornrulat lo'" at the rate of 7»15 pounds 2,**—D per acre. Two weeks later, the t^eatuent appeared to have been vary effective. The old leaves were de- •'a*»ir.'- at the surface and several new leevee were observed (Tig. 22). Thre<-' weeks later there were very few new leaves opening above the sur­ face. The treatment appeared to be almost as satisfactory as those in which two np lications had been used. A light, late-season application at the rate of 7.71 pounds 2,4—D or acre, had the Immediate effect of twisting the petioles and browning the leaves. One month after treatment, new leaves were opening at the •-jrface and they continued to appear during the remainder of the season. ■Pulmshes in the center of the plot were dead and no regrowth was ob- r<-rved. "■u^hrr The general sequence of events following the application of the isoro-nyl erter of 7,4-D on spatt<-rdock, jfunhar advena. war much like the r^oct caused by using any of the other 2,4—D compounds. If the leaves, rlor to treatment, extended above the surface, they would almost in­ variably be turned upside down by twisting *nd growth of the petiole which arched above the surface. The leaves that were hit by the spray 83 would slowly decay and new 1 earos would come from the rhizomes to re­ place the older ones at the surface. It is probable, although It was no* definitely determined, that theee leaves cane from the same rhi­ zomes which supported the injured leaves. With the tremendous size of the rhizome and amount of food stored within, this may well he the case. On July 22, 19^6, spatterdock was sprayed with an aqueous spray of the isopropyl ester of 2,h—D at the rate of two and one-half pounds per acre, A week later, the leaves which, previous to the application, ha/3 been projected above, were new prostrate on the surface. Two weeks after treatment, portions of some leaves showed signs of decay. Others i were of a yellow to greenirh color. Prom an examination five weeks after treatment, it was obvious that the regrovrth would soon re-populate the surface. Another application was made August 6 at the rate of three pounds '',h-D per acre in an oil spray. This did not prevent young leaves, previously visible beneeth the surface, from growing and unfolding above the surface by the end of the month. These appeared amid the coiled petioles of the decaying leaves wnich had been contacted by the oil spray. season Altuough the plot appeared thin by the end of the the following year the surface again became covered with leaves. An application at the rate of five pounds 2,4-D per acre s made July 11, 19^9, but even this concentration did not prevent the surface from becoming covered with new leaves by August 5» In general, it appeared that the isopropyl ester of 2,1|,5-? 84 caused a reaction by the leaves of spatterdock ■hr ?.,U-T> compounds. On July 27, 1 9 ^ , similar to that caused the ester form was applied at the rate of 1.39 pounds 2,i4,5-T per acre. After a few days the leaves r.nd petioles showed the typical twisting reaction to the 2,4-D compounds. ?ive days after treatment green, developing leevee could he seen coning from the rhisome, althou^di the surface was a mass of twisted leaves and petioles. Subsequent natural lowering of the lake level caused the new leaves to he projected ahove the surface. The regrowth continued to t o w the remainder of the season. Another application of the isopropyl ester at the rate of two pounds 2,^‘,5-T per acre made July 22 did not prevent regrowth from "becoming established within three weeks of spraying. Applications nade In August at three and four pounds 2 , k , 5-T per acre produced the typical twisting and curling of the contacted leaves "but did not prevent the development of new leaves from the extensive rhisone. !To applications were made In 19**9 of 1959 since the isopropyl ester of 2,^,5-T did not appear to have any advantages not possessed hy 2,h-D. An application of the phenyl acetic acid-2,4-D formulation at the rate of 6.89 pounds 2,h-D per acre, was made July 29. 1959 on spatterdock when the leaves were extended ahove the surface (7ig. 29). weeks the usual 2,h-D symptoms appeared (Fig. 39). Within two Shortly afterward regrowth from the rnlsome began to appear above the surface of the water. Mid-August applications of the phenyl acetic acid-2,4-D formulation at the rate of 3.15 and 9.71 pounds 2,h-D per acre, did not give satis­ factory control. 85 Contact herbicides T:~hha Or July 7, 19 **9. one pound of sodium pentachlorophenate pellets were dissolved in a pallor, of water. Bils was ap lied on cattail, T:~ha let if ol la. at the rate of 1**8.I* pounds per acre actual Na PCP. The solution sprayed out well and adhered satisfactorily to the upr*-nt and wax-coated leaves of the cattails which, by this time of yr~r. were quite tell end had. formed brown seed stalks. the leaves were browned but did not tend to lodge. A month later, An examination, five end one-hrlf weeks after treatment, showed that the neristematic zone hed not been injured and was continuing growth, pushing uo the old, browned growth to give a tiered effect. Another spraying on August 9 was made at the rate of per acre. pounds Although the leaves of the cattails were browned within a snort time after the application, the basal meristem was unaffected and continued growth. The addition of fuel oil and sulfon&ted castor oil to a solution of the pellets which had been dissolved in water, did not appreciably l.i’Vi-'jr 1U°.*4 pounds «fli: *t iveness of the salt when ap'lied at the rate of >er acre. There was considerable lodging, two weeks aft nr a.' llcation, but new shoots appeared from the rootstocks and the nerlsten continued growth. On July 13. 19*j8, one pound of TCA in a gedlon of water plus a commercial sticker—spreader (Triton B —1956) was applied on a Btjuare 86 rod plot of oattalls, Tyuha latlfolljs. and arrowhead, latlfolla. This was at the rate of 112 pounds per acre. treatment A week after the leares of the arrowhead were very light hrown and dry. The margins were a darker hrown. The cattails and sedges in the plot were li?^it hrown in color and, on superficial examination, the plants ■*oolted dead. Eighteen days after the treatment, the dried and shrivelled arrowhead leaves were conspicuous. ing from the crowns. nevertheless new leaves were develop­ At this time the treatment appeared to have heen successful on the cattails as the burned leaves were lodged and were very hrittle. The plants did not show the regrovth from the meristematie re­ gions that 18 so characteristic a response of this species to 2,^4-D appli­ cations. The next year this plot was again populated with arrowhead plants hut no cattails appeared except along one edge of the _.lot which adjoined a _particularly vigorous stand. A Hastings a plot sprayed July 8 with 112 pounds TCA per acre had developed considerable regrowth by the end of the summer. On August 12, 19*40, a dense plot of cattails was sprayed with TCA at the rate of 166 pounds leaves or r-erp. Wh^re the spray had contacted the they became hrown, hut other areas contained green plants which continued to grow. Complete coverage is essential for killing as TCA does not appear to he a translocated herbicide. At the rate of 22ii pounds per acre, TCA was applied to cattail on August 19. The spray solution contained a wetting agent and t*s applied as an aqueous spray. In a few days the cattail leaves were light brown and several days later they appeared dry and began to lodge or fall over. At the end of the season, this plot had little regrowth. In June of the 87 following year, control wai still apparent since less than a dosen new plants had regrown in the plot. A late season application was applied on August 25* 19^*8* at the rate of 112 pounds TGA per acre plus 2,4,5-T at the rate of 103.56 pounds per acre. A month later, in addition to the usual browning, th'' centers of the clumps, where regrowth first appears, shoved no green color. The following season, while It was apparent that there had been a reduction in the stand, quite a few ■nlents resumed growth. Control had not been as effective as where twice as heavy an applica­ tion of TCA had been used. On August 9 , 19**9. so.uare-rod plots of cattails were sprayed with TCA using culfoncted castor oil as emulsifier. The applications were an follows: flate »er acre (in pounds) 2?.6 Carrier wat cr 27.6 fuel oil 55.2 fuel oil Five days later, the leaves which had been hit by the aqueous c ;rny, were browned but the remainder still had green portions. A few of the bases were stained brown and, when pulled apert, revealed browr. areas within the tissue wheras normal plants were white. we <=>’:«5 nfter treatment Two the injured leaves were dry and had began to lodge but the seod stalks of fruiting plants had not fallen over. A month after treatment, the bases of some of the plants, when cut through, were white and turgid: othcre, which probably had re­ 88 ceived a heavier epray do saga, had a white center approximately the diameter of a lead pencil. Outside this center, the bases of the leaves v/«re browr. and apparently dead. At this tine there were seven new shoots, one ar.d one-half to two and one-half feet in height, which had cone from •■indor ground rootstocks in the treated plot. Tive days after treatment, the leaves of most of the plants which hod been treated at the high concentration were brown. The addition of fuel oil appeared to facilitate coverage: the oil aids in penetration of th** leaf tissue. Many of the bases appeared to be soft, due to a loss of turgor of the outer leaf tissues. Two weeks after treatment the leaves were dry and most of them were broken and leaning. A month after trep.tment, there were eight new shoots which could be soen to come from underground rhizomes. In the remaining plot, as in the or.e where fuel oil had been used, the leaves quickly took on a browned appearance. Two weeks after treat­ ment they were dry and lodged but a few had green centers. Three weeks after treatment, there did not appear to be fts many soft bases as in the plot where the higher rate of TCA was used. Many bases were turgid and appeared normal when cut through. An aqueous application of TCA applied July 11, 1950* on cattails at the rate of pounds per acre, whitened the foliage in a short time, but a month lat*»r there was evidence of new growth. first spraying with ammonium 3ulfanate was on June 2?. 19^8, at which time four plots of cattails were treated. cided with the time the pollen was being shed. These treatments coin­ One plot was sprayed at the rate of 160 pounds per acre while an adjoining plot received ammonium 89 sulfamate at the rate of 320 pounds per aere. A commercial vetting agent was added to the spray solutions. Two days later the leaves, which had been wet by the spray, were not tied a li<£it brown. No significant difference could be seen between thr» plots at thia time. Ten days later the leaves, especially in the plot which had received the higher concentration, were browned to the ground level. almost Two weeks after treatment, no green was visible on the plants. Apparently the only living plants were several along the margin of the plot. A n inspection, four weeks after treatment, showed r-’growth In the plot which had received the lower concentration and re— growth was observed in the other plot ten days later. The regrowth was in the form of new basal shoots and this continued through the remainder of the season. App arently the tops had been completely killed with the 320 pound application but the rootstock reserves were sufficient to provide for further vegetative growth. The other two plots were each sprayed at the rate of 160 pounds per ecre using a wetting agent. Although the treatments caused con­ siderable discoloration of the plants and severely affected the under­ ot ory of sedges and willows six weeks later regrowth was beginning to apuear and by eight weeks, complete recover:' was apparent. A later application on cattrils, July 1, at the same rate chow any better control On July 7, 19^*6, a did not thanearlier sprayings. plot of cattails was sprayed with PCP at the rrte of 80 pounds of parent phenol per acre, using kerosene as carrier. All plants in the plot turned completely brown overnight and, during the succeeding days, the leaves begrn to fall over as though beaten by 90 a heavy rain. The plot made a sharp contrast with adjoining areas hut e snail amount of new growth was evident in the central region of each plant he.se. Growth continued and within two weeks the new shoots stood up p.hove the dead and almost prostrate leaves. A spraying of cattails and r.ilkveed July 8 at the rate of 80 pounds of phenol per acre, had the same effect as earlier treatments on cattails. The milkweed leaves dropped within a week. Two weeks later, however, re- growth appeared from the apical portions of the milkweed stems and from the hasal, neristematic regions of the cattails. An application made July 28 at the rate of 17 pounds of phenol per acre on cattails, followed arucii the sane pattern as earlier treatments eTce_:t for a somewhat slower response. A late-season application was made on August 25 using 17 pounds of pher.ol per acre in oil. A month after treatment, regrowth of cattails was small hut this may have heen due to the cessation of growth from natural causes. In the spring of the following year, the growth of the treated plots showed no difference from the growth of the untreated plots. Cattails were sprayed August 9 the rate of 17 pounds of phenol ner acre using fuel oil emulsified with water and sulfonated castor oil. Five days later the usual browning was evident. After another five days the cattail leaves had further dried, they were quite white and there was considerable lodging. Two weeks after sprayin'-, it was noticed that the bases of some of these whitened plants were soft and that new shoots were coming from the underground raisones. to he seen a month after treatment Further lodging was as well as a few new shoots which 91 came from the merlstematlc regions of the old plants (those which had “been hit by the spray). Ob serrations up until the end of the season revealed an lnorease In the number of new shoots and thus indicated thrt control had not been satisfactory. Another application at the rate of 17 pounds of phenol per acre in fuel oil was applied on cattails, August 21, 19*^9. A month later some plants were well bleached and lodged with little sign of regrowth. At first it was thought that the soft brses of the plants were due to an effect of the chemical, but it later appeared to be a normal occurrence rt that time of the year re many of the plants from untreated areas had the pame characteristic soft base. The following spring the plants in this plot grew and showed little or no difference in abundance from ad­ joining, untreated areas. In June 195^ means of paths three scuare-rod plots of cnttails were laid out by cut between them at the limits of the quadrats. To de­ termine the density of the stand of cattails in the ’•'lot, counts of p-rt* were made in square-yard areas at the corners of each plot, thus riving four counts for each plot or a total of 1? for the three •'lots. On the day of the application, June 90, there was a slight wind therefore the amplications were not made under the most ideal conditions. The material was applied with a Sure Shot Sprayer at rates of 8, 16 and 2U pounds of phenol per acre. Tire days later It was obvious that the coverage had not been good as many of the plants remained the same while others in each plot were brown and were partly fallen over, typical re­ actions to treatment with this material. A month Inter there still 92 p-. peered to be a greater amount of lodginr in the plot which had received *y'r greatest concentration than in the oth«rs. All, however, were ex- h i'v iti n - regrowth. Fire weehs after treatment it was obvious that the regrovth was not r‘C :r.~ to be affected bj” the original treatments. therefore made. Final counts were ®ie number of dead and livinr plants were noted. A rev shoot, one and one-half feet in height, was observed next to prectic«oiy everp one of the dead plants. Results of these counts, as well sc these made nrevioup to treatment, ere Included in Table XII. TABLE XII EFTSCT OF A PCP IN OIL APPLICATION ON SEDUCING STANDS OF CATTAILS Bate per acre (in pounds) Original plant population Dead plants after treatment Percent red'’ict ion Regrowth | \c 20.0 2U l?.o • 72.C Cl 8. 1 0.0 *4.2 7.0 7 5.0 8.0 *».5 26.5 *».5 The first application of araonirm thioevanste at the rate of fort^ pounds per acre Hatcherv. used. vrs made on e-tteilr, «7ulp 5, 1 ^ , at the Hastings Fish Fuel oil, emulsified in vater vith sulfonrtec castor oil, vac A veeh after the appliestior., the leaves swelled of oi”1 and they- were slightlr browned. A month later, regrowth wne well advanced. The 93 use of veter •■lone As earrler In a subsequent •praying schedule, at the r t.'ir concentration, achieved less control than the fuel oil application. Two additional plots of cattails were sprayed July- 8 at the rate of 12o pounds per acre: vater vas used as a carrier in one and fuel oil in the other. A week later, the leaves in both plots vere hrovned' "but more r-o In the plot where the oil had been used. the characteristic oily smell and feel. The plants in this plot had When the bases of several of the plants in each plot vere cut, the centers vere greenish-white, indicating an incomplete kill. Regrowth subsequently appeared in both plots hovever, in the oil-treated one. less, There vas enotigh difference betveen this oil-treated plot and adjacent, untreated areas to warrant further applica­ tions with increased concentrations. The last spraying for the year vas made on August 8, 19**9. at which time two adjoining plots of the narrow-leaved cat tall .Tvnha august Ifolla. were treated. They each received ammonium tMocyanate at the rate of 320 pounds uer acre. One was applied as an oil spray at the rate of approxi­ mately ten gallons per acre; the other as an aqueous spray. good in soite of the height of the cattails. both nlots had become whitened. v/1th in a month (71/-. 31). A week later Coverage was the plants ir Some of the leaves had begun to lodge and the contrast between treated and untreated was great TOiere was no sign of any regrowth from the center?. were no new shoots except near the There eriphery where invesion may have bern responsible. Iferly the following spring It was clear that control had not been as successful as had been thought in the late fall. By June the plants were back er acre, did not show any nernanert control. 98 Hvnphaea On July 12, 19**6* a. square-rod patch of white water Illy, Ifiiinitiefi odora.ta. wae sprayed with PCP In oil at the rate of one-half pound phenol per acre. Twenty-four hours later, about ho percent of the leaves had ralien -wrgir.s. Two weeks after treatment, new leaves and flowers had appeared and were covering the browned and curled ones. These were sprayed with the lsopropyl ester of 2.U-D at the rate of 1.39 pounds per acre, using the aqueous spray. few hours. These new leaves were rolled within a On July 31, five days after the plot was re-sprayed, the margins of the leaves were still rolled, the petioles were twisted and many leaves were beneath the surface and in the process of decay. were floating in a normal position. Hone A week after spraying with the translocated herbicide, the twisted petioles were very conspicuous against a background of decaying leaves. At this time several new leaves were protruding and opening above the surface* but those which had been hit by the spray were upside down, submerged and disintegrating. On August 5, eleven days after re- 3praying, the regrowth in the plot v.t." sparse, about six new leaves were unfolded above the surface, the remainder were upside down and the petioles were coiled. nfter re-spraying, algae covered most of the surface. Three weeks The algae proba­ bly blanketteu the wrter surface and so discouraged further regrowth. On September 8 treated areas the plot stood out in sharp contrast to adjacent, un­ which had no algae but were covered with the leaven of tkn white wr.ter lily. A n application at the rate of eight pounds of phenol per acre, ap lied J-tly 10 did not seriously retard the growth of ITynpheea pdo r a t a . 99 ITunhar During the r t m u r of 19^8 several sprayingB of spatterdock, Sunhar ad v e n a . were made with ammonium sulfaaate. identical. In all eases the results were The leaves• which protruded or floated on the surface, were killed when covered with the spray. Thin did not interfere with growth fror. the rootstock and eventual re-population of the surface-. On June 23 an application using 128 pounds per acre was applied to spatterdock. At this tine nost of the leaves were supported ahove the 3-arface of the water. Twenty-four hours later, many of the leaves were curled to the midrih, as one would roll a scroll with hrown spots. and some were mottled Torty-ei^it hours after treatment, some of the lenves wore almost completely "browned, others had Just the centers green with a hrown periphery. These latter leaves remained erect and protruding ahove the surface during the remainder of the summer. ly browned, probably half of the -total, surface. S i x t e e n dayB after treatment 300a Those which vere complete­ decayed at, or Just below, the regrovth was evident in the fora of new leaves breaking t h r o n g and openinr ahove the surface film. On June 25 a square-rod plot of Uuuhar advena was sprayed at the rate of 128 pounds per acre. By July 3 fully half of the leaves were dead and submerged, the rest were partially browned with some portions dig” and disir.tegratin--. green. A few, a >roximately twelve, were large and These probably had received none of the spray since the plot wp.a denre and complete coverage was not obtained. treatment, the green centers of the leaves Eighteen days after which had been slightly covered with spray solution, were still conspicuously protruding above the surface. 100 Pour and one-half weeks after treatment regrovth had progressed to such an extent that It was decided to see what effect the application of a phenoxyacetlc acid derivative would have on this new growth. Accord­ ingly, this plot was sprayed with 2,^,5-^ at the rate of 1-39 pounds per acre. Three days later, the petioles and leaves were twisted similar to that of Nvmuhaea odorata leaves which had heen sprayed a day earlier with a similar amount of the isopropyl ester of 2,^-D. On August 2 new lenves were to he seen coming from the rootstocks, although at the sur­ face there was still a mass of twisted leaves and petioles. The lake level was down at the tine of the next examination and injured leaves were projected ahove during August. the surface. Continued, new growth was observed The old leaves either were projected ahove the surface or were decaying beneath it. Hew leaves continued to appear during the remainder of the season. Spatterdock, Hunhar advena. vas not seriously affected by sprayings of PCP up to forty pounds of phenol per acre. Within a few hours of c 'raying, the leaves were browned to a chocolate color and regrowth a-v eared a short while afterward. Although the leaves were killed which were contacted b y the spray, the application did not prevent new leaves from soon replacing the dead ones. 101 DISCUSSION Nigrosine As ft result of laboratory work, It was determined that a chemical change was responsible for the disftppearar.ee of the dye in Loon Lake. The dye formed an Insoluble compound with salts in the water and thus •',n~ reclnitated. In the laboratory this precipitate could he observed -- the leaves and on the sides or bottom of test jars. It was not found p ^ s I M e to put this precipitated dye back into solution. Variously formulated dye samples were obtained. Some of these formed irue solutions or colloidal suspensions while others were insoluble in Solutions or suspensions, however, of all of these were cleared in jar tents by Anacharis canadensis plants. Sometimes clearing took l~?c in j?r8 where there were no plants. On the basis of observations at pond TTo. ?, Hastings Tish Hatchery, w 't -p nigrosine was used, it vas shown that a decrease of oxygen and a corresponding increase of carbon dioxide dye. followed applications of the neither Eieher (75 nor Surber and Everhart (20) includ.ed observa­ tions on the oxygen—carbon dioxide ratio following nigroslne treatments, although the odor of putrefaction, as indicated by Surber and Everhert, vary likely denoted a low oxygen condition. To be effective in controlling submerged plants it would appear that sufficient nlgrosine dye must be added to the water to prevent li^it from reaching the plants. When the plants are almost to the surface, more dye will be required to exclude the li^it from then than if they 102 were not bo naar the surface. ’cncentretlon It le not easy to maintain thle high in view of the field and laboretory experience*. Ir. the concentration of dye vere maintained by repeated addition* *a r a sufficiently long period of time, it i* very lively that sub- ^lants wonld die. Decay of this plant material would lead to ~ lev oxygen— high carbon dioxide condition in the water. If it per- rirted for any considerable period of time, it is quite likely that + r>ir condition vould he detrimental to animal life. CHLQHITtf.TSD BETZETCES AND XYLENE When halnrced mixtures of chlorinated benzenes and xylene vere first used, the type of water appeared to be a factor in the stability of enulsions. When this vas shown to be the case (Table Till) only lake TW'ter was utilized in determining the choice of emleifier. Table YTT ir an evaluation of a number of emulsifiers when tested with balanced mixtures using Lake Lansing water. Ii-factory results. Those indicated gave Table T shows thet when a non— ionic araulsifier is used, temperature of the water, is not an important factor in the settling out of balanced mixtures. The influence of the amount of emulsifier on settling is shown in Table VI. With balanced mixtures nothin-* is gained by adding more then Just the minimum amount required s*nre there is not the stronr tendency of the mixture to either rise or fall, as is the case when the materials are utilized separately. Several attempts to show differences in effectiveness between balanced mixtures of orthodichlorobenzene-xylene and triehlorobenzene- 103 xr'lene did not give conclusive evidence of the superiority of ono over the other* Wh*>re weed beds were dense, it was soon apparent that the emulsions of balanced mixtures would not readily penetrate more than a few Inches. Increasing the rate of application did not increase penetration. tare*? which were made heavier than balanced mixtures Mix- for example by ohang!a* the ratio from 3*1 to 2:1, did not penetrate significantly "-rthe-** than did the balanced mixtures. The interference with the '1f• ’tr*bution of the sprayed mixture by weeds is apparent from an '■‘xan! nation of the results v/ith applications of balanced mixtures. ^vr.3 especially noticeable when a somewhat open growth of Chara in shallow water rates. was successfully controlled by spraying at low Similar rates only billed the upper few inches of a dense Ohara mat growing in deeper water. The inability of the emulsion to penetrate a mat of Chara. should not be attributed to a breaking of the emulsion due to temperature changes (Table V). On species other than Chara, hitler rates appeared to be a necessity. A tall but somewhat open (not dense) growth of Anacharls cnnadensls was successfully controlled by an application at the rate of I?"? gallons per acre but with a mixture containing comparatively ^?re trichlorbenzene to make the misture heavy. Potanoreton annli- ^ Tins was very resistant to treatment with the balanced mixtures and repeated trials with high concentrations did not give satisfac­ tory control. Prom the recults, there is some indication that better control can be obtained when applications are made early in the season. lontrol could be obtained early In the season with lower rates than /ere required for control later in the season. It would be highly desirable to investigate other balanced mixt'-re- than orthodichlorobenzene-xylene or trichlorbeneene-xylene as v 1 t.i this method It is possible to utilise materials which, because of f their weight, would be unsuitable if used alone or they would re■'lire too large an amount of emulsifier. 2,h-D PELLETS Although a considerable number of treatments were made on aquatic lantr with various phenoxyecetic acid derivatives & b fall or winter a plications and at rates considered to be reasonable, none could be cT.sidered as being effective. It can be seen from the results of tests (Table X) that in several instances, identical treatments ^id not give identical results. Differences in effectiveness be­ tween the materials are indicated. The sodium salt of PCP and a com- b* notion of this compound with 2,^4-D are more effective herbicides than are 2,h-D or 2,^,5-T. Derivatives or 2,h-D and of 2,^,5-T, when they were effective, required a longer period, cf 1 V e than die the m- compound 3 which have a more rapid, toxic action. When the rates in field trials were increased, trie difference in rf"^ctiveness was observed. It would appear, therefore, t h a t the application of 2,h-D and 2,h,5-T pellets, as formulated, would not be rr, effective nor a n economical means of controlling the weed species indicated. The use of PCP in various formulations, gives more promise 105 of uiflfuliiAit in thia M t h o d of aquatie plant control than doaa any derivative of phanoaQraootlc acid. Translocated Herbicides Although cattails are resistant to 2,h-I), some degree of control can be obtained by repeated folie-ge treatments. The results are better ’•’V.on there are made using oil sprays rather than aqueous sprays. Single applications of 2.^-3) at high concentrations, did not give the desired control. Treatments of five pounds 2,^-D per acre almost invariably catised the cattail leaves to become brown, to dry, to lodge r r.d to create the impression of a favorable control. Although a number c-f the plants would be apparently dead as a result of the treatment, in - rr.ctically all cases, by early fall there were signs of regrowth from the rootstocks. er.* exception If nc regrowth appeared by the end of the season with­ it did appear the followinr year. ■Pest results were obtained when an initial application of at least three poTuids per acre was made in June, before the pollen was shed. 'ext application, ** w at the same concentration, vme made six weeks later v h m regrowth was established. In spite of these two applications ♦otrlin'- sir or more pounds of 2,^-D per acre, there was evidence of — fgrowth from the rhizomes by the end of the season. As a result of a comparison of the acid, the ester and the amine salt of 2,*4-D. it dees not appear that, any of then is outstandingly superior over any of the others. The 106 Sagtttarla Arrowhead, Saglttarla l_at lfolla. appears to be more readily con‘r V e d with applications of the translocated herbicides than any other r roles tested. This does not mean, however, that all applications m ve the desired control. Of the treatments made, best results were obtained with mid-July to early-August applications at the three pound rote. Complete control was not obtained in all cases but better re- rult.r were obtained with 2,h_D than with 2,^,5—T. Pontedorla Plckaralveed, Pontefleria cordata, is not as sensltlwe to 2,h—D ar Ip arrowhead, Saflttarla latifolia, b u t it does respond favcrebly *c firlications. Three pounds per acre of either the ester or the phenyl acetic acid formulation gave good resultr. When light applications of 2,h-D were applied to plckerelveed, the bases of some of the petioles in the plot would soften and separate, causing the petioles to become detached and to float at the surface. A greater number would be caused to separate when spraying coincided with the beginning of the flowering period. cided with the flowering period July sprayings more nearly coin­ at which time food reserves are low. Regrovrth if more likely to occur following June sprayings because re­ serves ere otill relatively abundant in the root system. KVrnohnea NvpTphaee odorata has a large rootstock and is resistant to treat­ ments with translocated herbicides. An application causing maximum 107 shoe’-, applied when reserves are lowest, would allow a minimum amount of re growth. Single applications with either the isopropyl ester at rates up to + pounds per acre, or the phenyl acetic aeid-2,h-D formulation at ry'tes up to three pounds per acre, generally did not give satisfactory control. Vhen the petioles were short and where the rhlsone approached the surface, the isopropyl ester of 2,^-D was very effective at the rate or 5.5 pounds per acre. This would suggest the advisability of dropping ..rrter level, if this were possible, and then spraying the exposed plantc. A single spraying nr.de July 10 with the phenyl acetic acid-2, fcrauletion at 7.15 pounds 2,h~D per acre, twice the recommended dosage, ino very successful. Two applications of the phenyl acetic acid-2,A—D forrralation at 2.65 pounds per acre, were very effective or. HTymnhaea odorata when the first v-a? applied in late June and the second in late July. A slightly greater control was obtained by using one application of 2.65 pounds and a second at ^.15 : ounds per acre at an interval of a month. the isopropyl ester of 2,h-D at rates of Two applications of pounds, applied July 8 and r.f*ain on August 1? when regrowth became established, gave satisfactory control for the season. Hyphar !To great success was achieved in the control of spatterdoek, Thiyhar ad ve n a , with any of the 2,*»-D or ?,h,5-* formula tione used. All plants that apparently had been severely affected, later developed regrowth. Control by a single application seems unlikely to be secured with 108 t>ir cpeciee in view of tho tremendous slse of tho rootstock and tho food -♦•or^d therein. Vhen compared to the white water lily, spatterdock appears be more reeietant to 2,h—D. Tho phenyl acetic acid-2,h-D formulation did not appear to he superior to the readily available commercial formulations of 2,*4-D. Even at the - M e of 6 . 8 9 pounds 2,h-D per acre, control was not obtained with the acetic acid-2,h— D compound. Contact Herbicides *"y hr Contact herbicides, in generrl, did not prove effective on cattails. VJhen rates of TCA, PCP, ammonium thiocyanate, or anmoni,'m eulfamate were fl "lently hi^h, the applications were very effective in killing the ■*eaves. Occasionally more tha.r. .Just the leaves were rffected but in ^ c t ^ c a l l y every case, growth from the rhlsome continued the following '-’r*nr~. The use of fuel oil as carrier for these compounds did faeili— t-*»- coverage but did not materially affect the end result at the con­ centrations used. p - Addition of a small amount of spreader-sticker “beneficial in some applications. The cost of treatment with ihc contact herbicides is considerably greater then that with translo­ cated herbicides. Vhen a treated area was surrounded with untreated plants, new shoots often developed in the treated area because of invasion. Complete cover- therefore, is required in an attempt to control cattails. The ease of application and ap-arent effectiveness of alpha-hydro ay- 109 beta.-triehloroethyl sulfonic acid warrants the further study of this nr.terial for the control of cattails. Soluble sodium borate nay well sirc he Included in further study. Sa^lttarla Apparent kill of sprayed lee.ves of arrowhead, Sairittarla latlfolia. we* achieved vhen ammonium sulfamate and aononium thiocyanate were a l l i e d at the rate of 160 pounds per acre. from the bases of the affected leaves. Regrov'th, however, occurred Higher rates did not give the desired control. On the basis of the succeec obtained with one experimental spray­ in' of arrowhead using fuel oil, further study of this material is •■'rrranted. ja TTo applications of PCP or ammonium thlocyanato rave satisfactory control of pickerelweed. ©ie leaves were seriously effected but the barer of the petioles did not soften or separate. Even at the tine of merinrun growth, there apparently is sufficient energy left to enable re" leaves to reeeh the surface. Tn view of the comparative economy and good results which were obtained by the use of translocated herbicides on this species, the u-e of contact sprays is not recommended. Hrnrohaca The control of white water lily, ITyrrshaee odorata, by contact 110 „rr ,r 4^er £oee no^ appear to be as satisfactory at does control with ‘rr^'-rlocated herbicides. An application of PCP 1rffr. by an application of 2,*»-D followed, two weeks gave an appearance of goor-har The large and extensive root system makes it difficult to effect -'-ntrol of fluohar advena with either contact or translocated herbicides, ir.r-onl-in sulfanate and PCP were effective in killing leavee contacted the spray, hut they were not effective in preventing regrowth in ted arer.c. Ill STJMM&BY ■*. The use of nigroeine dye for the control of submerged e.quatlc Irrte was not satisfactory. Apparently salts In the water react with the dye to form insoluble precipitates and thue the dye is ren-vrd from solution. In a hatchery pond of .75 ecres, although the <’yo ras not present in sufficient quantity to control weeds, the ^ ’crolved oxygen content of the water, two and one-half to three fort below the surface, dropped to a low level wfcorns the carbon <:ioxide content increased. This, is net considered to be a healthy condition end thus the use of nirrosine dye is not recommended for *h<-' control of aquatic plants in hatchery ponds. Balanced mixtures of orthodichlorohenrcne-xylene and trichlorbr>n2 ere-xylene were found, to be effective in the control of s\ibm.cr~ed weeds. The emulsified, balanced mixture remain? longer in contact with the submerged plants than do either of the components. Smaller quantities of the mixture are required for the control of Jhr.ra than for other weeds. Ar-licet ions made early in the sea­ s'" five nromise of better control than those nrde later. Po ta.no- ~et sr an 1 lfolius a’ ear? to be part ieularly resistant tc the balanced ui xturer. ?. The use of 2,4-D and 2,^,5-T compounded into pellets, did not n-venr to be a satisfactory means of controlling submerged weeds. Vinntiticc of 2,^-D-PCP pellets required to be effective were con­ sidered to be too high in cost from a practical point of view. 112 The application of dry herbicides on the hot ton of a drained r>ond ' not give satisfactory control. Pest results from the use of translocated herbicides occurred applications coincided with the period of flowering. Applice- t ’-'f at the rate of three pounds 2,^-D per acre at this time gave •r -' control of plckerelverd, Pontederia cordata. Waite water lily, ’‘’rno^haee odorata. required an additional treatment a month later. ''“ "•’.I, Tyohp latlfolia. was not satisfactoriIp controlled bp two - rr.p ar.pl lest ions. Arrowhead, Sagittarla latlfolia. was the most '-itiT»* to B’*pi iCP-1iorr of the trarrlccatod herbicides. The large quantity of food reserves in the rootstocks of aquatic "l^r.ts nakes then difficult to control bp spray applications of con­ tact herbicides. 2ver at flowering, reserves are sufficient to pro- *,*'**» for rerrovth vhen the tons are killed with contact herbicides. LIT2EAT0RE CITED Anonymous Controlling weeds. United Stetes Soli Conservation Service, U o r t h e m Great Plains Region. Regional Biology Handbook. 72-76. 19*9* ^ ’c o d , Robert R. Control of weeds on irrigation systems. United States Department of the Interior, Bureau of Reclamation. 1-1*0 . 19*9 . Vr.11, Robert C. Relationship between available fish food, feeding habits of fish and total fish production In a Michigan Lake. 'iichi.-er A,'*ricultural Byperlnent Station. Technical Bulletin 206. ir*e. Rau-mn, Aden C. 2,h_D and some emergent aquatics.. Effects of butyl erter of 2,*-Dichlorophenoryacetic acid on some emergent aquatic plants. The Progressive 7ieh-Cu.lt nr ist. °:71-?7. 19*7* Penman, Aden C. The effects a.quatic. vegetation. Trans. of ammonium eulfanate on emergent Twelfth To, Am. Wild. Corf. 3*6-355. 19*7- Cornell, J. H. Eradicatim of emergent ncuatie vegetation with 7,’:-D. The Progressive 7lsh-Culturist. 11:113—119. 19*9« r*. rk.cr, Ceorge Aniline dye in aquatic weed control. Tigmt. 11(3):193-197. 19*7. Jrl. Wild. Gerkinr, Shelby P. Destruction of suhnerged aquatic plants by 7,^-r. Jrl.Wild. Kent. 12:221-227. 19*6. Rrr.iley, Delnar E. A summary of four years of chemical control of aquatic vegetntion at Buckeye Lake, Ohio. State of Ohio, Division of Wildlife, Section of Pish Menagenent. Bulletin 2W'. 19*9. Uirrt, W. Harold Bencclor 3C. The Reclamation Era. 3?s76-?',. l?1-?, Jc-'-ror, H. W. Weed control ir. small ponds.Virginia Agricultural T.y-erinert Station. Bulletin *'25* 19*9 • liornn, T. and Shaw, J. !u.c'< potato, (Saglttarla latlfolia). thirty days after treatment with an aqueoue solution of the Isopropyl ester of 2.A-D at the rate of 2.7B pound8 2 (*4-D per acre. Tig. 20. D u c k potato. (Sagittarla latlfolia). thirty days after treatment with fuel oil at the rate of 40 gallon* per acre. Fig. 21. Pickerelweed, (Pontederla cordata) . thirty-one days after treatment with phenyl acetic acid-2,^-D at the rate of 2.65 pounds 2,^-D per acre. Fig. 22. White water lily, (Hymohftea odorata). thirteen days after treatment with phenyl acetic acid2 , a t the rate of 7.15 pounds 2,^-D per acre. 0 Tig. 23. White water lily. (Mymohaea odorata) . "before treatment. Fig. 2*. White water lily. (Hymohaea odorata) . fifteen day® a f t e r treatment with the ieopropyl ester of 2,h-D in oil, at the rate of 3*^6 pounds 2,^-D per acre. •Jig* 25* White water ill;/, ( before treatment. odorata) . Tig. 26. White water lily. (Hxar^heea odor at a) . twelre days after treatment with phenyl acetic acid2»h-D at the rate of 2.65 potmde 2,^-D per acre. Fig. 27. White water lily, (N.vnuhaea odorata). Twenty-seven days after treatment with phenyl aeetie acid-2,^-D at the rate of 2.65 pounds 2 ,4-D per acre. Fig. 28. White water lily, (Nynnhaee odorata). fifty-two day* after treatment with phenyl acetic acid-2,**-D at the rate of 2.65 pounds 2,^-D per acre, and 25 days after spraying the regrowth with 7*15 pounds of the sane formulation. Pig. 29. Yellow water Illy, (Hunhar adrenal. before treatment. Pig. 30. Yellow water Illy, (Huohar adrenal. six­ teen days sifter treatment with phenyl aoetle acld-2,^-D at the rate of 6.89 pounds 2,^-D per aore. Hig. 31* Harrow-leared oattail, (ftnaha thirty days after treatment with aramoniua thioeyanate at the rate of 320 pounds per aore. - Fig. 32. Harr ov-1 eared oat tail, (Troha tllffTWUf^V\^ treated the prerious fall with alpha-faydrosy-beta-triohl orethyl sulfonlo aoid at the rate of 200 pounds par aore. Photographed in July.