mamas mrwnncma RESUM'PTION 9F ROOT GROWTH ‘ . ‘ DNTRANSPLAHTED TREES THESIS" FURTHEDEGEEE OF M. s. r { Clifford B; Cody ’- 49.34 Factors Influencing Resumption of Root growth on IranSplanted Trees by Clifford B. Gordy A ”H5513 Submitted to the Faculty of the Michigan State College of Agriculture anu Applied science in partial fullfillment of the require- ments for tne degree of taster of Science Department of norticulture hast Lansing, nichigan 1954 ‘3z/¢3% TH E516 u Add. lifwfirlnfltué R ”I a .5! ,1 EH?" Factors Influencing Resumption of Root Growth on TranSplanted Trees 0y Clifford B. Cordy INTRODUCTION The successful tranSplanting of small fruit trees is relatively easy in regions where the winters are warm enough for root growth to start soon after fall planting. However ‘where root growth is not resumed until Spring, possibly after shoot growth has started, it is sometimes difficult to get a high percentage of trees to grow satisfactorily. This is true eSpecially of cherries. It is recognized that the moisture supply of trees comes practically entirely through root hairs and small roots. All of these root hairs and other absorbing roots are cut or rubbed off during digging or consequent handling and planting. This leaves the tree with no efficient absorbing organs while water is being tranSpired as rapidly as before digging. This loss can in a measure be offset by pruning the tOp; severe pruning, however, is generally undesirable for other reasons. Unless the tOps were heavily pruned, the trees would con- tinue to lose more moisture than was absorbed until the roots were able to produce new water—absorbing organs. As this nor- mally takes place at about the same time that the buds leaf out, it is readily seen that adverse conditions such as warm, dry weather at this time might cause heavy losses. It was the object of this eXperiment to determine the season of planting which would give earliest and most vigor- ous rooting and to treat the roots before planting in an effort 'rs:» -2- to stimulate an even earlier and more vigorous reSIMption of rogt growth. if in this way it mere possible b0 cutain Visor- ous root growth a few days or a week earlier than usual and before the buds leaved out, the tree would be in better condi- tion.to withstand adverse conditions. REVIEW OF LITERATJRE It has long been recobnized that the absorbing ability of tree roots is greatly reduced by the processes of trsnSplanting and that careful handling of them is essential to the well being of the tree. In 1676, Worlidge (16) reco mended that the tree roots be soaked over night in water before planting in order that they might be better able to reestablish themselves and re- sume their normal functions. Pruning the roots in varying deérees of severity has been practiced to induce the remaining roots more vigorously to pro- duce new rootlets. Results from this practice, however, have not been positive. Card (2) reported that for Nebraska condi- tions, good results were obtained by pruning the roots lightly but that no pruning was even better. Bedford and Pickering (1) also reported that trimmed roots produce fewer rootlets than untrimmed ones. A light pruning of the roots, especially a removal of the fibrous roots was reported by ialbert (12) to give best results under Kissouri conditions. The small fibrous roots seldom resume growth and merely serve to prevent satis- factory packin0 of soil about the remaining routs. in 1908, cedford and BiCKering (1) reported that bending or notching roots did not stimulate roat formation near the H a- -0- notCn or send but that new rootlets were formed near the base of the roots. it has frequently been observed that, althouéh root fornation does not take place directly from the callus tissue of cut surfaces, many of the new roots dd arise from near the cut ends of the old roots. Goff (5) observed that trees which were not tranSplanted resumed root growth in the Spring most vigorously at the apex of the main r0)ts and on the principal branches of the main roots. more recently chemicals have been much used eXperiment- ally in forcrng plants into early arowth, to break the rest periods of plants and to cause woody and herbaceous Cdttiués to send out roots more quickly. Chemtcals have been used very little, however, in the treatment of roots during trans- planting. harvey and nose (I) reported that illuminating gas and ethylene were very toxic to roots, even when present in Very small quantities. it caused Curliné, swelling and later deatn. ourtis (4) reported a marked stimulation of root form- ation in woody cuttings by treatment with potassium perman- ganate and lesser stimulation by certain other chemicals, including boric acid, sucrose and warm water. Nutrient sol- utions were found to be inJurious. hlein \9) reported similar results. Chandler (5) found that more grape cuttings took root and the roots grew faster if the cuttin5s were stood with their bases in a weak solution of some ckidixing abent for 24-48 hours before planting. ihe use 01 wet peat moss as a -4- medium for rootiné Cdtblfl$b was investioated by hitchcock and Zimmerman (8), who stated that azalea cuttings root un- usually well but that callus formation is hindered. iney believed that the acid reaction of the peat was the feetor favoring rout formation, as a peat medium which had been leached with tap water or neutralized with an alkali did not give as good reaponse. Coatiné the roots of grafted Hazaard and hahaleb trees with paraffin was rep3rted by Tukey and arase (13) to be slightly detri ental, the trees beinb slower to start growth in the spring. Althoudh ”he action of these agents in stimulatins root browth is not definitely nnown, sevcral theories are advanc- ed to explain it. Stuart {11) reported that the action of ether is probably of the nature of an arreSt or complete cessation of growth and as a result of this suSpension of all activrty on the part of the plant, the usual resting period is greatly abridbed and the plant is at once thrown into growth when subjected to suitable growing conditions. In explaining the stimulating effect of potassium per- manganate on cuttinos, Curtis(a) emphasized the subocstion that it increases respiratory activity activity by cataly- tically hastening oxidation. fimong other suggestions of- fered are that it causes a Change in the nature of the food supply, and that the food supply balance between roots and tOps is upset in favor of the roots. The effect of the sucrose is prObably due to its beinu absorbed and stored -5- for use in root develOpment, it using recognized that a high caroohydrate content is conducive to increased root orowtn. ihe season at which trees are planted seems to have some effect on their ability to become satisfactorily es- tablished. Whitten (15) reported that fall-planted trees made a steady tOp growth after the buds once started, seem- ingly having sufficient roots to maintain them. in Spring- planted trees, however, the o.ds stOpped L,roning suon after starting, apparently waiting for the roots to resuhe grouth and absorption. He found also that fall-planted trees re- sumed root growth uelow the Irost line by midninter and con- tinued all winter, while the Spring-planted trees did not resume root groutn until after the Duds had started to grow. Upshall (14) also found fall planting somewhat superior to spring planting. harris(l) reported that the oursting of the suds marnedly depressed root respiration, although it increased prior to their sureting. In the early stages of shoot growth, respiration of the roots remained at a low level. Otuka (10) reported that root growth in apple seed- lings ceased when the soil temperature at a depth 01 50 cm. fell to 7°c., usually in hovember, and began again wnen the surrounding soil temperature rose to 0°C.,usually in rebruary. hfir’mi l .41.- l1". 1.. cm haterial_ used. ihe materials used in this experiment consisted of 270 apple trees, 260 large and 70 small cherry trees. The apples -6- were miscellaneous seedlings about five years old which had been transplanted several times and a few of which had seen sudded. rhey were at this time growing in the college nursery at East Lansing. The large cherry trees were hahaleb seedlings obtained from the braham station at urand gapids. These seedlings were four years old and averaged seven feet in height. ihey had been growing in a nursery row and had not been previously disturbed. Ehe small cherry trees were all on Lahaleb roots; 42 had seedling tops and the remaining 28 had been budded. rhey were Obtained directly from the nursery row at South haven. Qutlune of ireatments. As the effects of season of planting and method of win- tering were to be considered, as well as effects of special treatments, it was deCided to plant some trees in tne fall, store some indoors in cold storage, heel some in cut of doors, and leave some undisturoed in the nursery row. ihe stored trees were to be planted in the spring. refore oeinD planted, each group of 10 trees was sub- jected to some special treatment. In most cases this treat- ment consisted of soaring the roots in a Leah solution of some oxidizing agent. ihe solutions to be used were prepared and placed in five gallon containers, the roots of one or two groups were then immersed in each container to approximately the crown and left there for 48 hours. After being used onCe -1- the solutions were discardd. As soon as the CL'CL.CI;;C;;.C we completed the trees were planted. The treatments used were:- 30 treatment; pctassium per- manganate 0.11; acetic acid 0. 01X; ether runes, O.b cc .er J. liter; hydr05en peroxide, 0.08M; sucrose, O.J34I. or 8%; hp .’ boric acid, O.CCsh; potassium ferrocyenide, O.ClH; tap tater, term tater (4000,); peat extract, peat placed about routs durinp storage and then planted, and slitting the roots, both crosswise and lenéthwise. r" Preparation of irees. All the apple trees, except those to be left for Syrihé digging, were dug Nov. 1-3 and heeled in individually as dug. Cold weather then set in and prevented their removal until Nov. 21. They were then ddé, divided into groups of IO and the tOps pruned to a ship and this shortened beck. Very little pruning has done on the roots except to remove binding r00ts and some of the fibrous roots. The trees to be fall-planted were subjected to various treatments and planted. The rennin- ing trees were either heeled in or placed in cold storape. All the cherries, except those left for spring diéging' were dug on Kov. 26 and heeled in in peat until Eov. 50, when they were brought to East Lansing. Their treatnent from this point on has the same as that 5iven the apples. Althoudh the trees stored indoors had their roots trap- ped in moist sawdust, the tOps became dried and none of the cherries so stored grew in the spring. A few of the apples -5- pres but as they may have been stored in a more favorable position the data obtained from them have been discarded. The small onerry trees stored under the others and with roots in peat came throuph in good condition and made good QrOtth in the spring. ObserVations. The fall-planted trees mere set Vov.ao—Dec. 3. The ground became frozen soon after planting and, except for occasional short periods, it remained frozen during tne mister. All spring-planted trees were set April 1-5, which was only a few days after the frost left the ground. Trees mere dub up at intervals during the tinter and Spring tut no new root gromth Was observed until April 65. At this time all of the fall-planted apples and most of the youné cherries, regardless of season of planting, shoved current root growth. None of the fall-planted older cherries showed grosth and, except for one tree in the potassium per- manganate group and one in the potassium ferrocyanide group, there were no roots forming on any of the sprino-planted apples or cherries. The new rootlets appeared almost entirely from very fine, fibre-like roots about the size of stout thread, very few coming from the larger roots. All trees dug during the winter and at this time were replanted for future Observation. These results indicate that trees planted late in the fall, just before the ground freezes, do not resume root -9- growth in this section until syring. However, when favoraole growing conditions arrive, their early activrty shows them to be in oetter growing condition than early Spring-planted trees. In agoraising the various trees as dug, each was assigned an arbitrary value based on number and size of rootlets. The same standard was used for all plots but in order to keep the numoers from oecomino too large, the standard was raised as the season advanced. That is on April 25 any tree with from 4-6 new rootlets was given a value of 2 out on hay 5 a similar tree would be given a Value of l as roots at that time were generally more numerous. Therefore in taole I the :80 :5 e (n (‘1 ‘ fact that the numbers do not become larber as the advances does not indicate that there were no more roots, but that the standard had been raised. On may 4-6 four trees from each fall-planted glot and three from each Spring-slanted plot were removed and examined. A larger majority of the rootlets were from the larger roots than in the material examined on April 33. Cuts and injuries were not as yet callusing. The fall-planted apple trees main— tained their early advantage over the spring-planted, and the fall-planted cherries showed a much better start than the syring-planted. The spring-planted apgles were about as far advanced as the fall-planted ones were 10 days previously and the fall-planted cherries were about a week in advance of the Spring trees. Another feature was the slight but -10- consistent superiority of the spring-dug trees over the heeled-in trees (table I). There was no appreciaole differ- ence between the fall and Spring-planted small cherry trees. They were all rooting nicely. Aoout half of the trees dug at this time were replanted, the remainder were discarded. TABLE I Average Rating of New Root Growth in Trees Subjected to Treatments (Group averabes) Treatment April 23 May 5 hay 20 June 10 Total Fall-Planted Apples . Check .67 1,50 1.77 - 3.94 Roots Slit .67 2.75 1.30 - 4.72 water .67 2.25 1.83 - 4.76 Kano4 3.00 5.00 5.50 - 11.50 Acetic acid 1.00 2,25 2.63 - 5-88 H502 1.00 2.50 3.11 - 6.61 Sucrose .33 3.75 3.30 7.58 Ether .67 5.00 1.71 - 5.38 Peat on roots 2.33 4.75 2.00 QoQS Peat extract 1.00 3.25 8.30 5-55 Spring-dug Apples Check 4 .67 2.00 2.00 4.67 Water - 1.67 1.80 2,00 1.47 Acetic acid _ 3.00 3.00 2.67 .67 Sucrose ' - 2.00 3.00 2,67 7.67 H302 _ 2.67 2.00 2.50 7.17 Peat extract - 2.00 3.40 2.00 7.40 K3Fe(cn)6 .55 1.00 2.00 1.10 4.45 Heeled-in Apples Check - .33 1.60 1.60 3.53 Roots slit .00 1.40 .60 2.00 Hot water - 1.33 1.60 2.00 4.93 Boric acid - 1.33 1.40 1.50 4.23 KMn04 .67 1.33 3.00 2.40 8.07 Fall-planted Cherries Check - 2.0 2.8 - 4.8 Raots slit - 1.4 1.8 - 3.2 Water - 2.2 1.6 - 3.8 KMn04 - 3.8 3.0 - 6.8 H202 - 4.2 1.8 - 6.0 Sucrose - 3.0 2.2 - 5.2 Ether - 3.0 1.8 - 4.8 Boric acid _ .5 .4 _ 1.0 -11. TABLE I (cont.) Treatment April 23 Kay 5 Kay 20 June 10 Total Spring-dug Cherries Check - 1.3 2.6 1.0 4.9 Hot water - 1.7 2.6 1.5 5.8 KKn04 - 1.0 2.8 2.2 6.0 Acetic Acid - 1.0 1.6 2.2 4.8 H302 - 1.3 1.8 1.0 4.1 Peat extract - 1.7 2.2 2.6 6.5 Heeled-in Cherries Check - 1.0 1.2 2.0 4.2 Hot water - 1.0 1.2 2.3 4.5 KMn04 - 1.3 1.5 2.4 5.2 Acetic acid - 1.3 2.0 2.6 5.9 H302 - 1.0 1.2 1.0 3.2 Sucrose - 1.0 .8 2.0 3.8 Fall-planted Young cherries Check 0.0 1.0 1.4 .6 3.0 Acctic acid 1.0 2.0 2.7 3.0 8.7 Peat on roots 0.0 1.0 2.6 1.4 4.0 Peat extract 0.7 1.3 1.4 1.8 5.2 The remaining fall-planted apples and Cherries and five trees from each group of spring-planted apples and cherries were examined on May 20-23. There was now very little to choose between the fall-planted and Spring-dug trees, either apple or cherry. However, more than half of the fall-planted trees dug at this time had been dug and replanted on either April 23 or May 5; this was undoubtedly a setback for them and had they been left undisturbed until this time, the fall-planted trees would very probably have been superior to the Spriné- dug ones. There was still a noticeable difference betmeen the heeled-in trees and the others, those heeled-in during the winter being noticeably inferior to both fall-planted and Spring-dug trees. ~12- Contrary to the Kay 4 observation, most of the rootlets were now appearing from the larger roots, chiefly from an area starting a little below the crown and extending down about four inches. These rootlets were large and substantial, ranging between one and three inches. There were not many rootlets out near the ends except for an occasional cluster where the broken end had callused over. The numerous small rootlets from small fiber-like roots which had previously predominated were no longer so evident, and there appeared to be an actual decrease in numbers. This was no doubt par- tially due to concealment by the increased numbers of root- lets from larger roots. Then, too, some of the first formed rootlets may have lost their white color with age and thus have become indistinguishable from the older roots. This browning of the older rootlets, if it actually cocurred, may account in part for the lessening of the difference between the fall and Spring-planted trees. The remaining rootlets on the fiber-like roots were no larber than when last ob- served. Previous observations had disclosed little callusing of wounds; now, however, most of the wounds had a rim of callus tissue around them and in some cases, rootlets arose directly through this callus rim. This was especially true of cut and broken ends where clusters of well develOped root- lets two inches long were occasionally observed. On June 10, all the remaining trees were dug and their roots examined. The spring-dug apples were still decidedly -13- superior to the heeled~in trees in root formation. The Spring-dug and heeled-in cherries, however, were on a par. This condition in the cherries is very different from that at the previous digging when the Spring-dug trees were def- initely better roited. ine ¢round was rather dry at this time and from the appearance of the rootlets, they had dis- continued growth as no very small rootlets were appeariné. most of the wounds and by this time started callus form- ation and some were completely callused over. There was still no marked stimulation of root formation from any of these wounds, either natural or purposely inflicted. helation of 10p Growth 22 hoot arowth. rhere appeared to be a sllsflt but definite relationsnip between the amount of shoot growth and root develipment, as shown in table II. In this table the average shoot growth on each tree was compared with the arbitrary value assigned its root development. These figures show that with an increased amount of shoot growth there is a slight increase in root development when individual trees are tne units of comparison. However, examination of table IIa shows that those treatments which produced the most marked stimulation of root development did not produce a like stimulation of tOp growth. in fact there is no correlation between root and top growth when the groups are used as units instead of individual trees. This would in- dicate that what correlation between root and top growth there was, was due to natural tree vigor. It seems also that -14... this correlation would have been more marked had it not been for the treatments which by stimulating root growth and not affecting tOp growth would naturally tend to destroy any ex- isting correlation. TABLE II Growth of Root and TOP on Kay 20 Shoot growth Root Growth (arbitrary) in inches Fall Spring Fall SprinQ apple apple Cherry Cherry 0 1.5 ,9 1.5 1.6 l 2.3 2.1 1.9 1.7 2 2.6 2.7 5.3 2.7 3 2.5 5.3 4.0 TABLE Ila Growth of Root and Top on May 20 (group avereges) Fall apples Fall cherries Root Shoot Root Shoot Treatment growth growth Treatment growth 5rowth Roots slit 1.28 1.64 Boric acid .4 .2 Ether 1.71 .57 hater 1.6 .5 Check 1.78 .94 Roots slit 1.8 .5 Water 1.85 1.16 H503 1.8 .5 Peat on roots 2.00 .75 Ether 1.8 .5 Peat extract 2.29 1.71 Sucrose 2.2 1.0 Acetic acid 2.65 1.25 Check 8.8 .9 Hpog 5.11 1.59 KMnoé 5.0 .4 Sucrose 5.29 1.45 KhnOé 5.50 1.55 A comparison Letween the fall-planted, Spring-dug and heeled-in trees reveals intereSLing figures. (Table II). In the apples, the Spring-dug and fall-planted trees made equal top growth out the heeled-in trees were inferior. With the cherries, the method of overwintering had no measurable effect on tOp growth, with the possiole exception of the top growth on hay 25 where the spring-dug trees seem to as some— what oetter than the heeled~in trees. The results correspond very clasely to the root growth results. figsults thained py_y§rious Treatments £12395 2.1.9:; This group of trees was handled identically as all other groups but it received no special treatment. There was one check plot with each of the different plantings, making three apple checks, three cherry checks and two young cherry checks. In table III all of the checks have been given a value of 100 and the values of the treated plots have been changed corresgondingly. tater To determine whether any stimulation secured from a treatment involving soaking was due to the water or the chem- ical in the solution, three groups of trees were soaked in tap water at room temperature. Otherwise they were handled exactly as were the checks. The results (tables I, III) show that soakinQ in tap water had no effect on either the time or amount of rooting, the water groups being quite close to the Check groups, sometimes slightly better and sometimes slightly poorer, with the differences insignificant. Roots slit The effect on rooting of a mechanical injury was tested -16.. by lacerating the roots with a snarp knife. Some of the cuts were made around the roots, some the long way of the roots and some being grouped near the root ends. These slits did not callus over until root formation was well under way on other parts of the r00ts and very few new rogtlets were observed on the slits. As root formation followed very closely that of the check group, it was assumed that tne slitting had no effect early in the season. It is possible that as the season advanced and callusing progressed, new root formation would be stimulated. Potassium_perman5anate oOaKin6 for 48 hours in a 0.1 M. solution of potassium permanganate caused considerable stimulation in the product- ion of new rootlets, especially in the early part of tne sea- son. marked benefit followed the use of this chemical on 00th cherries and apples. It being by far tne oest material used. nootlets were being produced freely in this group while in the cheek group, rootlets were just beginning to appear. All during the season roitlets were much more freely produced and of more vigorous growth than in the check group. This is similar to the findings of Curtis (4) with cuttinos. rotassium ferrocyanide one Although this material Was used on only/group of apples, it appeared to have definitely detrimental effects. In the very early season the rootlets deveIOped about the same as in the check group but later deveIOpment was very slow and -l7- the few small rootlets formed did not appear viborous. inere was also a marked effect on tne teps. when the check group and others were well sprouted this group snowed no sign of tOp growth, out the buds were still alive. Later the last year's growth alt died, out a few buds develOped from the older wood. Acetic aCid _ A 0.001 1. solution of acetic acid caused variable amounts of stimulation. ine apples treated with acetic acid were slightly but consistently better than the check. it seemed to have little effect on the older cherry trees except in one case there tne treated group was much superior late in the season. The small Cherry trees so treated were much superior to tne check all through the season. On these trees tne rooting was earlier, more vigorous, and the new rootlets were very numerous. ihis was by far the best treatment on the young cherries, producing an undeniable stimulation. .bOI‘lC EAClLL ine eneiiy trees tieateu with a U.Utz M. solution of boric acid were definitely inferior to the check trees all through the season. The treated group produced only a few roots and these were small and not very vigorous. The boric acid appeared to have little if any effect on the apples, the treated group being about the same as the check. Sucrose Soaking for 48 hours in an 8 per cent solution of sucrose fri ‘ a led to produce marked stimulation. A few of the -18- observations indicated benefit and it is possible that there was some increased growth, but as the increase was not con- sistent it may have been mere variation. hydrogenpperoxide Soaking the roots in a 0.08 M. solution of hydrogen peroxide failed to change materially the time or amount of rooting in either cherry or apple. Numerous tests agreed closely with the checks. It is possible that the oxidizing prOperties were dissipated before they had a chance to stim- ulate the roots, as the solution was left in an Open contain- er during the treatment. rarer. Exposing the roots to ether vapor in a closed container at a rate of 0.5 cc per liter had no perceptible effect on the rooting. Trees thus treated rooted similarly to check trees. Egg; pp roots Placing a double handful of German peat around roots of the trees at planting time appeared to have some stimulatory effect. Early in the season trees so treated produced more rootlets than check trees and at midseason they were con- siderably more advanced, but after the soil dried, the root- lets became eXposed to the air and shriveled. If some earth had been mixed with the peat it is possible that the benefit would have been derived without the later shriveling. -19.. Peat extract A bucket of peat was placed in five gallons of hot water and cooled; trees were soaked in the extract for 48 hours. This had little if any stimulatory effect, he trees rooting about the same as the checks. Warm water Soaking in water at 40°C. for 8 hours had no effect on rooting, the trees being similar to the checks. TABLE III Summary of Treatments Root Growth in PrOportion to Untreated Trees APPLES Cherries Small cherrie Treatment Pall Spring- Heeled Fall Spring Heeled Fall planted dug in planted dug in plant Check 100 100 100 100 100 100 100 Roots slit 119 57 67 Water 120 117 79 Khn04 292 229 142 125 124 Acetic acid 149 186 98 140 290 H202 168 153 125 84 76 Sucrose 187 164 108 90 Ether 137 100 Peat 230 136 Peat extract 166 158 133 173 K3F€( CN)6 95 Hot water 140 118 107 Boric acid 120 21 DISCUSSIOJ In preparing trees for planting, it may be necessary to re- move a few fibrous roots to allow preper packing of the soil but care should be used not to remove an excessive amount of them as it is these small roots that produce the first new root- lets of the season. The larger roots do not produce t1 r00 ets -20.. until about two weeks later. Other investigators have re- ported similar results. In sections where winter injury is not comuon, fall planting is to be preferred because of the earlier routing Obtained. If fall planting incurs risk of winter injury it would be preferable to plant early in the Spring. Whitten \15) in reviewing Opinions on this question concluded that when winter injury is nut involved, fall planting generally produces better trees than Spring planting. Even when trees were set in the Spring as early as possible after the frost left, they were not as early in roOting as trees planted late in the fall. Their buds, how- ever, Opened at the same time. If the Spring planting had been delayed for a week or two, wnich is as early as most trees are set, it is prooable that the rooting would have been even more delayed while the buds would have been de- layed but little. The earliness and Vigor Of root growth can be influenced by chemical treatment without influencing the top growth. Potassium permanganate was the best material used to stimulate the roots and trees treated with it rooted much better than untreated trees. Acetic acid was also good, particularly on young cherry trees. Placing peat around the roots was beneficial until the soil dried, when the peat became dry and the roots shriveled. -21- As this stimulation affected only the roots, they were thus given a short but Opportune time in which to resume the processes of water absorption. in this way the tree should be better able to supply its tOp with moisture by the time the bids start to leaf out. Leaving the trees standing in the nursery row was supe- rior to digging in tne fall and heeling tnem in out of doors. Although roots were produced no earlier, they were more numerous and vigorous; hence, if fall plantins is not feasi- ble, the trees should be left standing in the nursery row until Spring. SUMhARY l-Earliness and vigor of rooting were influenced by season of planting, storage, kind of tree and by special treat- ments. Z-Fall-planted trees bave earliest rooting, tne spring-dug trees being next best. 3-Apples resumed root growth earlier than cherries, but after a few weeks there was little difference between comparr- ble groups. 4-host of tne new rootlets early in the season were produced from fibrous roots. 5-Cuts do not callus over until root formation is well under way. b-TOps and roots usually start growth at about the same time 7-Chemical stimulants affect root growth only. -23- 8-Chemicals producing tne most stimulation were: potassium permanganate, acetic acid, and peat placed around the roots. 9-Potassium ferrocyanide was detrimental to apples and boric acid was detrimental to cherries, but did not affect apples. ACthWLELGLBNIS ihe writer wishes to acknowledge the assistance of professor V.R. Jardner and professor 3.0..Bradford in plannins and carrying on the work and for reviewing and criticizing the manuscript. -25- LITERAIURE Cirnb 1. Bedford, n.A.n., and Pickering, 8.3. 9th. rpt. woburn experimental fruit farm. 1308 2. Card, r.w. Methods Of tree planting, Heb. Agr. Exp. Sta. Bul. 56, 1898 5. Chandler, W.h. North American Orchards, p.198, 1938 4. Curtis, Otis F. Stimulation of root growth in cuttings by treatment with Chemical compounds. bornell univ. Agr. Exp. Sta. rem. 14, 1918 5. Goff, n.S. assumption of root growth in spring. 15th Ann. Rpt. his. Agr. Exp. Sta. p.240 1838 6. harris, G.h. Studies of tree root activities. scientific Agr. 10:564, 1930 7. harvey, E.M., and nose, h.C. ihe effects of illuminating gas on root systems. Bot. Gaz. 60:27, 1915 8. hitchcock, A.E. and Zimmerman, P.W. Jariation rooting response of CuttanS placed in media of different pn value. Proc. Amer. Soc. nort. Sci. 25:585, 1926 9. Klein, Irwin, nooting response of conifers to treatment with chemicals. Proc. Amer. Soc. Hort. Sci. 28:447, 1931 10. Otuka, iosio, studies on the beginning period of the growth and the rest period of the apple root. (prelim- inary note, resume). hes. hul. Aar. nxp. Sta. South Manchurian hallway CO. 30. b 1931 11. Stuart, william use of anaesthetics in tne forcing Of plants. Vt. Agr. hxp. Sta. 19th. Ann. apt. p.279,1906 -24- Talbert, T.J. Iranspianting fruit trees. 40. Agr. nXp. Sta. Sul. 245 1937 iukey, h.5. and Brass, Karl The eifect of parafiining, pruning, and other storaue treatnents upon the growth of roses and cherry trees. Proc. Amer. Soc. hort. Sci. 28:48u 1951 Upshall, ‘w‘.ii. i‘imperiments in transplanting; sweet Cherry trees. Proc. Amer. Soc. hort. Sci. 27:2b9 19S Whitten, u.U. An ichStloathH in transplanting. IO. Agr. Exp. Sta. hes. nul. 55 1919 worlidee, John A treatise Of cider, London. p.“O lbvo {INHIIIWIIHIH 293 03046 8064 lWiIlIWH “I T"‘ u u S" N| A“ Wall H“ 3