M W L \ NIH HHWWIWI‘.| #04 I” | (130101 RESPON$E QF CERTAIN VAREETEES G‘F SNAP SEAN {PHAfiEfiEUS VULGARB) TO SEED TREATMENTS Thesis far {he Eegrea 0% M. S. MICHIGAN STAN CGLLEGE [fieciah Eiégabafh Cehn Wcfié‘é? This is to certify that the thesis entitled "Response of Certain Varieties of Snap Beans (Phaseolus vulgarie) to Seed Treatment" presented by Adah Elizabeth Cohn ' has been accepted towards fulfillment of the requirements for __M..S.._degree inllanLEathology I I I ; I 0-169 ‘ , A? —_ ’ WW , " I j '1" (W 1 “ “xiii ; ‘« : *fifi RESPONSE OF CERTAIN VARIETIES OF SNAP BEAN (PHASEOLIB VULGARIS) T0 SEED TREATMENTS BY ADAH ELISABETH 20m _ A THESIS Submitted to the Graduate School of Michigan State College of Agriculture and. Appliea Science in partial fulfillment of the requirements for the degree or MASTER OF SCIENCE Department of Botany and Plant Pathology 1949 -m-_“ A: ~A. we meals; ACKNOWLEDGEMENTS I 'ieh to express my appreciation to Dr. John R. Vaughn for his guidance, advice and helpful criticism given through- out the course of experiaentation and preparation of the nanuacript; to Dr. Donald J. DeZeeuw, under who“ guidance the field work was done, for hie many valuable suggestions. I would alao like to thank Dr. W. D. Baton for his aid in the statistical analysis of the data. TABLE OF CONTENTS Introduction....................... Materials and Hethods.............. Experimental Results............... Emergence....................... Emergence Period................ Yield........................... Discussion and Conclusions.;....... Summary............................ Literature Cited................... Page 13 13 2# 32 33 42 anyone]: OF CERTAIN VARIETIEB 0F SNAP BEAN (PHASEOLIE YULGARIS) TO SEED TREATMENTS W Treatment of seed with a chemical protectant to prevent damping-off has increased greatly during the last twenty years (27). Ito estimates have been made of the losses caused by this disease, but ltcNew (15) states that in many cases seed treatment has led to a more vigorous stand and a very sub- stantial increase in yield. Damping-off is a seedling disease which affects many agricultural and horticultural own. It is caused by soil- inhahiting fungi, such as Rhiaoctonia sp., Fusarium sp. and Pythium sp. (3) . Two phases of the disease are recognized (11) . The first phase is pre-emergence damping-off and is characterized by seed decay, sometimes occurring before the seed germinates. This results in a marked reduction in the number of plants emerging as compared to the number of seeds planted. The second phase is post-emergence damping-off; an area of the stem near the soil surface rots away and the seedling falls over. Leaves on diseased plate may turn dark green at first and brown lesions may appear on the stem and on the tap root before the plants fall over. Often the pri. my root is completely rotted. The disease spreads readily under environmental conditions favorable for the causal organ- iam, such as cool, wet weather. -2- In general, vegetables benefit greatly from seed treat- ment. The first widely used protectants were organic mercury compounds which came in use in 1912. From 1933 on zinc oxide and capper oxide have been utilized on a large scale. The shortage of these metals during World War II gave an incentive to intensive research with organic compounds other than mer- curials (12). In sue vegetable crops, such as peas, cabbage, spinach, lima beans, beets and cucumber benefits of seed protectants are quite consistent. Relatively little mention is made in the literature concerning the advantages of seed treatment for beans. This is in contrast to the other important leguminous vegetable, peas, for which seed treatment is of great impor- tance and on which many studies have been made. This becomes understandable on comparing the type of growth of both crepe . The cotyledons of the pea which contain stored food remain underground . The plants depend on this food during the early stages of their growth. The cotyledons of the bean are raised above the ground and are food-manufacturing organs for some time (22). Therefore, the cotyledons of peas are highly susceptible to attack by dampingé-off fungi. Disintegration of the cotyledons is of prime importance in the damping-off of these two crops (17) . Peas are a cool climate crap and grown under environmental conditions which approach the opti- mum for these fungi. In general, beans are planted at higher temperatures, so that the seedlings emerge relatively quickly and the cotyledons are underground only for a short period. -3- This disease antenna is known under several names, such as damping-off, Rhizoctonia disease, stem canker, stem rot, seedling blight (10), and bean rot (20). Under certain condi- tions it may become’serious. Moore (20) states that beans are grown in the Southeastern States from October in South Florida to early April in coastal Virginia. During this period pre- vailing cool temperatures delay germination. Under such con- ditions the seed will be attacked readin by soil-inhabiting fungi and rot away . Though the disease is caused by several fungi, the symp- toms are similar. [core (20) describes two phenomena, the first one being failure to germinate, the second one duping- off of the lateral roots. In the latter case the plants are not killed, but are weakened, due to the infection of the root system. Townsend (25) describes the symptoms of Rhisoctonia dis- ease, caused by g. g_o_l_a_n_i_ Kuehn, which vary with age and part of the plant. He also mentions rotting of the seed before or during germination. The seedling may emerge twisted and stunted, with red lesions on the stem and near the soil sur- face. Very young seedlings may fall over. Older plants may remain erect, but gradually turn yellow and wither. Some plants may recover sufficiently to send out new lateral roots above the point of infection or near the soil line. These plants will not be as vigorous as healthy plants. Harter and Zaumeyer (10) describe seedling wilt caused by Pythium ultimum Trow. This disease shows the same symptoms as a: .4 ‘vfi' 4‘ ll: -4- post-emergence damping-off in other vegetables . The young seedling is infected at the base of the stem in the region of the root and the organism spreads upward, causing a soft and water-soaked lesion. The primary and trifoliate leaves become flaccid and never regain their original turgor. The roots are also invaded and eventually become soft and watery. When the stem of the plant turns woody, it is no longer sus cept ible . h The same writers mention Pythium root rot caused by Pythium debaryanum Hesse. This causes post-emergence duping- off in the young plants . In the older plants stem rot or hollow stem may appear. The same damping-off symptoms can be caused by Corticium 3315;; (Prill. and Del.) Bourd and Gals. (finisoctonia _s_g_1_a_n_:_t_) . In the older plants the latter disease is characterized by stem canker or red brown lesions on the stem. This corresponds to the Rhisoctonia disease described by Townsend. Baker (2) showed that Rhisoctonia may be carried in the seed of eggplant, tomato and sinnia. No reports have been found indicating that the fungus may be transmitted by bean seeds . Soil and seed treatment have been applied to control the disease. Related (9), in his early discussion of damping-off, recognises that the organisms causing this disease are harbored in the soil. He believed that control should be applied to the soil rather than to the ailing plant. Soil treatment with - 5 - chemicals or steam has always played.an important part in the control of the disease, especially in the greenhouse (21). The disadvantages of application in the field are great, as the known soil treatments are costly and time-consuming. During recent years the trend has been to treat seeds with chemicals. The principle underlying this method is to protect the germinating seed against fungal invasion (11). For reasons not well understood, this treatment may also give protection against post-emergpnce dampingpoff. Inflow (17), in discussing seed treatment of spinach, suggests that enough chemical may escape to partially sterilize the soil around the plant. ‘Ihile the seed coat of spinach is pushed.upward by the young seedling, some chemical may be rubbed off on the soil to protect the young plant around the base of the stem. Moore (20) found that benefit derived from seed treat- ments of beans may vary considerably with environmental con- ditions. He conducted a five-year’experiment from 1931 to 1956 with two plantings per year» Throughout the experiment the variety Stringless Black valentine was used, except in 1932 when tests were conducted with Bountiful. In general, treatments were more beneficial in wet, cool years. Of all materials tested only ChlorOphenol Mercury 30% and Ethyl leroury Tartrate 2f‘gave slight increases in.stand, while Semesan appeared somewhat injurious . Clayton and Nusbaum,(4) planted the varieties Asgrow Black valentine and Tendergreen at two locations in South -5- Carolina in 1942. The seed was treated with.Spergon and Arasan. No improvement in stand was noted. ucNew (19) published a chart for vegetable seed treatment. A note is added to the effect that beans usually do not respond to treatment, and.in most areas it is not suggested, ‘When it becomes desirable, Spergon applied at 0.21 per cent by weight of seed is preferred, followed by Arasan at 0.16 per cent and Semesan at 0.21 per cent. During l9#3 and 1944 studies on vegetable seed treatments were sponsored by the Seed Treatment Committee of the American PhytOpathological Society (23, 24). In 1943 snap beans were tested in fifteen places throughout the United States. Spergon at 0.2 per cent by weight, Arasan at 0.125 per cent and Formats at 0.2 per cent were used on the Refugee variety. Significant differences over the control were found in three tests. In two of these three tests Spergon was best. In one test the increase in germination over Arasan and Formats was statistically sig- nificant. ‘No significant difference was found between Arasan and.Fermate. Tests on snap beans were not included in the 1944 trials of the Society. Gould (7) reported the results of a trial in‘lashington in 1943 using the Blue Lake variety. In no treatment was there a significant increase of germination of treated seeds over the control, but Spergon applied at 0.5 per cent, 1 per cent and 2 per cent by weight of seeds, showed a consistent small in- crease. The same was true for Arasan and Fermate at l per cent -7- and 2 per cent and 2 per cent Geresan at 0.5 per cent. 'rwo per cent Geresan caused a decrease in germination, when ap- plied at l per cent and 2 per cent by weight of seed. Semesan showed an increase, while zinc oxide and Dow m 111 and Dow 63 were injurious. In a survey of vegetable seed treatments carried out over a period of three years, Gottld (8) found that Semesan, Spergon and Dow GB were beneficial to beans and that yellow Cuprocide was injurious . Davis and Haensler (5) used the protectants Semesan, Spergon, Thiosan and Tuads on beans in two field and one green house experiment. Sigmificant increases over the control were obtained in one field planting and in the green house. All treatments increased germination; the best performance was given by Tuads in the field and by Semesan in the green house. Object of the Qesis The object of this thesis was to test varietal differences in snap beans in relation to seed treatments. Little is known whether there is an interaction between the different varieties of a vegetable and the fungicide used to protect them against duping-off. [dew (18) points out that pea varieties of the Alaska type are smooth-seeded and less in need of seed treat- ment than the wrinkled-seeded varieties. The smooth-seeded varieties have starchy cotyledons, the wrinkled-seeded ones sugary cotyledons (26). It might be postulated that it is ll; -8- easier for the fungi to attack the sugary cotyledons than the starchy ones. Forsberg and Binkley (6) tested the pea vari- eties Rogers f95,ilarvel and Laxtonian with the fungi Rhinoc- tonia, Pythium, Fusarium and Ascochyta. Some interaction was noted between varieties, treatments and fungi; the interaction between varieties and.fungi was the most important one. ldNew (16) tried.three varieties of lima bean, Henderson Bush, Clark‘s Green and.Fordhook with yellow Unprocide at l os./100 lbs., Thiosan at 1.5 os./100 lbs., Spergon at 1.5 and 3 oz./100 lbs., Formats at 2 os./100 lbs. and Semesan Jr. at 1.5 oz ./100 lbs. Four plantings were made from Kay 20 to June 11, l9h3. Different environmental conditions prevailed during the emergence periods of the four plantings. The re- sults with the three varieties were fairly consistent. Spergon at 3 os./loo lbs. was most beneficial. Formats and.Thiosan were better than Semesan Jr. Treatments increased yields in the same ratio as they had increased emergence. Even.tbough treatment of bean.seeds seems to have limited application, it was thought that a thorough study of varieties might reveal differences in regard to benefit derived from.seed protectants. It is the general oontention.of workers with beans that varieties of the wax bean type are more susceptible to damping-off than varieties of the green bean m... For this reason six green bean and four wax bean varieties were tested. Five different chemicals were tried out on each variety. Two of these coupounds are standard protestants for vegetable seeds, while the other three are newer fungicides which have not been introduced commercially . - —~.\-.' -9- Five plantings were made at the Michigan State College fans in East Lansing during the spring and summer of l9#8 to sample the effect of different moisture and temperature con. ditions during this season. The writer is of the opinion that through this method less time is needed to prove or dis- ‘prove the value of seed protectants, especially new compounds, under actual field conditions. Initial tests on new fungicides are made in the laboratory and in the green house. ‘When their performance is satisfactory, they are tried out in field tests (14) . Even though conditions at repeated planting dates may not be similar to those normally prevailing during the usual planting time, it still would give an indication of the per- formance of these compounds under various environmental con- ditions in the field. This method.seems of most value to those crops that are usually planted at higher temperatures, such as beans, corn, lima beans and the crops planted-during the summer to obtain a fall crop, such as lettuce, spinach, carrots, beets and.peas. Testing in different years at the usual planting dates remains imperative for the most promising compounds, but testing may have to be carried out over fewer years, when severe a1 planting dates are used in one year. laterials and Methods For the purpose of this thesis damping-off is understood to mean the following: a) Pro-emergence damping-off, or failure of seeds to emerge, indicated by the number of seedlings appearing ~ 6"" -10.. as compared to the number of seeds planted and b) Post-emergence damping-off or softening of stem tissue at the soil level, causing the seedlings to fall over. In the course of the experiment only the first type of damping-off was encountered. The following ten varieties were used (1)“: Green Beans I. Asgrow Black Valentine 2. Dwarf Horticulture 3 . Bountiful 4. Asgrow Stringless Green Pod 5. U. S . No. 5 Refugee 6 . Ranger Wax Beans 7 . Sure Crap Fax 8. Topnotch Golden Wax 9 . Round Pod Kidney Fax 10 .Pencil Pod Black Wax The dates of planting and the weather conditions prevail- ing during the time it took the seeds to germinate, called emergence period, are tabulated in Table l. The weather data were obtained from the U. S . Department of Commerce Weather Bureau in East Lansing, Michigan. Each temperature figure is followed by its standard deviation. Table l.-Bean variety seed treatment trials. Dates of planting; maximum, mean and minimum temperatures and total precipitation during the emergence periods Temperature in “’1" during Total precipitation emergence period in inches during Planting Date ‘ emergence period laximum lean Minimum I 5/29/48 73:8 61:5 50:4 1 .02 II 6/ 14/ 48 74:8 6 5:7 55:8 2 .26 111 6/23/48 81:6 71:6 52:7 1 .80 IV 7/17/48 83:53 7234 60.4 o . 54 v 8/8/48 31:3 6813 56;} 1 .76 a) Purchased from Associated Seed Growers, new Haven, Conn. -11- It was fortunate that, with the exception of Planting I, rain fell either on the day of planting or one day later. Planting I was made during a dry spell; no rain fell from Kay 23 till June 4. The five seed protectants used in this experiment are listed in Table 2. Spergon and Arasan have been in use as standard materials for a number of years. McCallan (14) studied a group of 157 inorganic and metallo-organic chromate complexes and related materials in the green house. Of these materials L 224 and L 640 were considered to be promising enough to be tested in the field. In Plantings I, II and III, L 640 was applied at the rate of 4 oz./100 1m. IniPlantings Iv and v, it was applied in addition at the rate of 2 oz./100 lbs., as it was noted that at the higher rate it caused injury to some varieties. As far as known to the writer, no data have been pub- lished about the performance of DO! I 800 as a seed pro- tectant. As stated before, Gould (7) found the related com- pound Dow m 111 (20 per cent dicyclohexylamine salt of dinitro-orthyi-cyclo-hexylphenol) injurious to beans . Under the conditions prevailing that year Dow 98 (65 per cent 2, 4, 5, trichlorophenol) seemed injurious. However, when considered over a three-year period (8), it was slightly beneficial. It was noted that Dow F 800 had a tendency to crystallize out, and was, therefore, difficult to apply as a dust. 1 -12.. Table 2.-Seed protectants tested, their trade name or code number, chemical composition, application in percentage of weight of seed and in ounces per one hundred pounds of seed Trade name or Active ingredient Application code number In pct. by In ounces weight per 100 lbs. of seed of seed Spergon TetrachlorOparabenzo- 0.33 4 quinone 98 pct. Arasan Tetramethylthiuram- 0.16 2 disulfide 50 pct. c. a. c. co.‘EL .Zn0.Cu0.Cr03-xH20 0.33 4 L 640 0.16 2 cs & CO CO. 7Zn0.2HgO.201‘03.H20 Oe33 4 L 224 Dow F 800 2,4,5 trichlorophenol- 0.33 4 chloracetate 50 pct. wettable a) Carbide and Carbon Chemical Co. All treatments were applied five or six days prior to planting in containers, previously used for this purpose. The seeds were shaken vigorously with the protestants for five minutes. Seeding in the field was done by hand. The usual agricultural practices were followed. Five replications were used.within each planting. As there were ten varieties, five chemicals and a control plot with no treatment for each variety, every replication con- tained.sixty plots. One hundred seeds were planted per plot at three inches distance from each other. -13- Treatments and varieties were completely randomised within each replication. Only six varieties were planted in Planting V: Dwarf Horticulture, U. S. No. 5 Refugee, Ranger, Sure Crop Wax, Topnotch Golden Wax and Round Pod Kidney Wax. Sufficient data had been obtained for the other varieties in the pre- vious plantings . To determine the influence of the treatment on the speed of germination counts were taken every two or three days, until the counts remained constant. The mean emergence period was determined by the method of Kotowski (13) . Each increase in germination is multiplied by the number of days since planting. The sum is divided by the total emergence. It is advisable to count germinated seeds every day, but due to the large number of plots per planting (300), this was not possible. All data were analyzed by analysis of variance. Egperimental Results Emergence ‘ V It'is evident from Table 4 that germination was highest in Planting I in almost all cases as compared to the correspond- ing plots in the other plantings . Emergence tended to decrease in Plantings II and III and to- increase again in Plantings IV and V. This might be due in part to the activity of bean mag- gots in Plantings II, III and IV, but especially in Planting III. Their presence could be noted by the ragged, chewed appearance of the first true leaves, the death of the growing -14.. point and.the holes punctured in the cotyledons. They are known to suppress germination. Rye was plowed under four weeks before Planting III and seven.weeks before Planting Iv. This probably accounts for the great number of bean maggots, as these insects prefer decaying organic matter. Table 3 shows the the analyses of variance for each of the five plantings. In all cases treatment and variety vari- ances are highly significant in comparison to the error vari- ance, showing that germination was significantly different between varieties and.between treatments. The highly signifi- cant interactions of treatments and.varieties in all five plantings indicate that varieties responded differently to 'treatments. ‘Variations due to replications are highly sig- nificant in Plantings II, III and IV. This is probably partly due to soil heterogeneity and.partly to an uneven distribution of the bean maggots. The least significant difference offers a means of com- paring the averages of the five replications of treated and untreated plots within each variety. On this basis each treatment was tried out ten times in Plantings I, II, III and IV and six times in Planting V, except L 640 at the rate of 2 oz./100 lbs. which was tried sixteen times in Plantings IV and.V. Table 5.shows how many times each treatment gave.sig- nificantly higher or lower emergence than the control at the l per cent and.5 per cent level and how often there was no significant difference. Columns 1 and 2 show how many times -15.. Table 3.-Analyses of variance of emergence of ten varieties of beans treated with five seed protectants at five planting dates Factor Sum of squares Degrees of Variance F freedom Planting I Treatments 409 .2 5 81 .8 5 .76" Varieties 3917 .1 9 43 5 .2 3o .6 5" Repli cations 67 .0 4 l6 .7 1 .18 Var . x Treat . 2633 .7 45 58 .2 4.104” Error 4 .8 23% 14.2 Total 10 2 2 Planting II Treatments 1437.2 287.4 11.10** Varieties 7992 .4 888 .0 34 .29" Replications 1197 e9 299 05 11 e%** 88 .5 3 .42” 25 .9 Var. x Treat. 2982 .8 Error 10 . Total 20713 .2 Planting III [0'0 else ULpVMm Treatments 3549 .4 5 709 .9 11 .814“ Varieties 21375 .3 9 2375 .0 39 .51” Repli cations 2844 .5 4 711 .1 11 .83" Var . x Treat . 1213: .5 2465 1235 .2 l .75“ El‘ror e 0 e1 moi 5% Plantin IV“ Treatments 2987 .1 6 497 .8 , 10 .54!” Varieties 8482 .7 9 942 .5 19 .90“ Repli cations 932 .8 4 233 .2 a .94“ Var. x Treat. 3912.6 52 12.2 1.54" Error 1 02 .2 . Total 2 52 . £9 Planting Y’eb "' Treatments 2457 .8 6 409 .6 13 .6 5n Varieties 2295 .2 5 459 .0 15 .30** Replicat ions 228 .6 4 57 .2 l .90 Var. x Treat . 3067 .2 30 102 .2 3 .40** Error 4921 .4 164 30 .0 12970 .2 209 a) L 640 at the rate of 2 oz./100 lbs. was added to the other treatments b) Six varieties were tested ** Significant at 1 per cent level -16.. Table 4o-The average emergence of ten varieties of beans treated with five seed protectants at five planting dates Treatment Variety J Control Spergon Arasan L 640--4a F800 L224 L640--2‘D Plantigg I Asg -B1 .Val . 91 92 89 93 88 89 Dwarf Hort . 87 88 87 91 84 88 Bountiful 96 95 94 98 96 97 Asg .S tr .Gr .Pod 93 ’ 91 91 91 93 95 U .S .No . 5 Refg . 87 92 89 89 87 91 Ranger 83 91 91 73 80 93 Sure Crap Wax 90 90 92 93 91 90 Tom .Gld.Wax 86 87 85 73 84 87 Rnd.Pod Kdn .Wax 85 89 92 82 85 87 Penc.Pod Bl-Wax 95 91 94 94 93 93 Least significant difference at 5 per cent level 4.7 Least significant difference at 1 per cent level 6.1 Plantin II Asg .BE .Val . 86 93 89 9O 88 93 Dwarf Hort . 82 87 85 88 83 86 Bountiful 98 96 95 93 95 95 Asg .S tr .Gr .Pod 93 94 93 91 90 91 U .S .No .5 Refg . 91 92 92 91 90 93 Ranger 80 87 88 64 71 93 Sure Crop Wax 87 92 88 90 92 87 Tapn .Gld .Wax 81 85 84 65 80 79 End .Pod Kdn .Wax 84 92 90 80 86 88 Penc .Pod B1 .Wax 94 96 92 95 93 93 L.S.D. at 5 pct. 6.3 L.S.D. at 1 pct. 8.3 Planti III Asg .Bl .Vai . 78 79 74 77 77 82 Dwarf Hort . 67 71 74 71 68 71 Bountiful 88 92 88 93 85 94 Asg.8tr.Gr.POG 88 88 86 89 84 85 US .No .5 Refg. 84 85 81 85 85 86 Ranger 69 , 80 76 55 55 83 Sure Crap Wax 83 86 83 84 79 85 Tepn .Gld .Wax 66 74 66 60 50 80 Rnd .Pod Kdn .Wax 56 74 72 76 62 72 Penc .Pod Bl .Wax 84 89 89 91 81 91 L-SODO at 5 pct. 906 L.B 0D- 3t 1 pct. 1206 a) Applied at 4 ox ./100 lbs. b) Applied at 2 oz ./ 100 lbs. -17- Table 4 ( Continued) Treatment Variety control Spergon Arasan L 640-43 F800 L224 L640-2b Planting IV Asg .81 .Val . 81 80 84 86 80 84 85 Dwarf Hort. 71 80 79 80 65 83 81 Bountiful 88 84 93 94 88 93 93 Asg .S tr .Gr . Pod 79 87 79 87 71 84 84 U .S .No .5 Refg . 85 83 86 88 84 88 82 Ranger 75 87 83 79 68 88 82 Sure Crop Wax 87 81 82 ' 77 .79 86 . 84 Topn .Gld .Wax 73 81 78 76 76 84 70 Rnd .Pod Kdn.Wax 62 78 77 76 74 85 78 Penc .Pod Bl .Wax 82 91 91 89 86 84 91 L3 .D. at 5 pct. 8.5 LISODO at 11301;. 11.2 Planti Dwarf Hort . , 83 82 85 78 72 84 83 0.8 .No . 5 Refg. 89 9O 90 90 86 86 91 Ranger 76 88 86 85 65 89 88 Sure Crap Wax 87 90 87 87 87 87 89 Tapn .Gld .Wax 78 83 78 78 78 87 81 R118. .POd Kdn .Wax 66 89 88 82 77 87 82 Les eDe at 5 pct. 607 L.S.D. at 1 pct. 8.9 a; Applied at 4 oz ./ 100 lbs. b Applied at 2 os./100 lbs. each treatment was significantly higher than the control at the 1 and 5 per cent level. Columns 6 and 7 show the same for the times each treatment was significantly lower than the control. Columns 3, 4, and 5 indicate how often there was no siglificant difference from the control. In column 3 those cases which were greater than the control are listed, in column 4 those equal to the control and in column 5 those smaller than the control. It must be borne in mind that the control is different for each variety in each planting. -18.. Table 5.-The performance of five seed protectants in relation to the emergence of ten varieties of beans at five planting dates Significant No significant Significant increases over differences from decreases under control control control Protectant ' 1 pct.” 5 pct.* > " < 5 pct. 1 pct. con- con— con- trol trol trol Spergon 7 7 22 2 8 Arasan 6 3 18 8 ll L640-4‘ 4 1 24 3 8 1 5 F800 2 o 9 8 22 5 L 224 ll 2 20 3 10 L640-2b 3 2 7 l 3 * at 5 per cent level seat 1 per cent level a; applied at 4 oz ./100 lbs. b applied at: 2 oz ./100 lee Table 6 shows the percentages of the total significant increases and decreases from the control. The siglificant increases or decreases of'each protectant are added together and their amounts are expressed as percentages of the total number of times each treatment was tried. - 19 - Table 6.-The performance of five seed protectants in re- lation to the emergence of ten varieties of beans at five planting dates expressed in percentages Pct. significant Pct. significant Protectant increases over decreases under control control Spergon 30.5 Arasan 19.6 1640-43 10 .9 13 .0 F800 4 .3 10 .9 L224 28.3 L64o-2b 31 .3 a) applied at 4 om./100 lbs. b) applied at 2 oz./100 lbs. Spergon and.L 224 had the greatest beneficial effect on germination followed by Arasan, L 640-4 and F 800 in that order. ‘While L 224 was significantly greater than the control at the l per cent level in more cases than Spergon, the latter led ' with the number of significant increases. Treatment L 640-2 cannot be compared with the other treatments on basis of the number of trials for each treatment, since it was tried 16 times against the other treatments 46 times. On the basis of percentages it performed.slightly better than Spergon and about three times as well as L 640-4. Treatment L 640-4 caused a significant decrease from the control in germination in 13 per cent of its trials, while L 640-2 showed.no injurious effects. This indicates that L 640 applied at the rate of 4 oz./100 lbs. was toxic to certain bean varieties and.its application at 2 os./100 lbs. is preferable. Arasan, a standard -20.. treatment for many vegetables, performed more poorly than Spergon. Treatment F 800 was least beneficial; its per- centage of significant increases over the control was lowest and it ranked second in injurious effects. In those tests with this compound, which showed no significant differences fra the control in germination, it tended to be lower than the control. It is possible that the poor performance of F 800 is due to a too high application of the compound. In Table 7 the significant increases in germination over the control are distributed over the varieties and plantings in which they appeared. Germination of the varieties Asgrow Stringless Green Pod, Bountiful and Sure Crop Wax was not affected by the treatments . It can be noted from Table 7 that the responses of cer- tain varieties to beneficial treatments tended to appear within the same plantings. Both Spergon and L 224 increased germination significantly over the control in Asgrow Black Valentine. Dwarf Horticulture showed benefits from all treatments in Planting IV. Treatment U. S. No. 5 Refugee was benefited only by Spergon in Planting I. In this case it is not possible to observe any tendency of benefit by treat- ments in relation to the planting. Ranger and Round Pod Kidney Wax were the varieties most sensitive to seed treatments, as germination was increased by one or more protectants in every planting. For Ranger the greatest effect of seed treatment was exerted in Planting V, where all protectants, except F 800, showed a highly signifi- cant inorease over the control. Considering all plantings -21- Table 7.-Distribution of significant increases in emergence caused by five seed protectants on seven varieties of beans at five planting dates Plantin Treatment 5 I II III IV V Asgrow Black Valentine Spergon L 224 Dwarf Horticulture Spergon L 640-4" L 224 L 640-210 Arasan n as n**** U. S . No. 5 Refugee Spergon * Ranger Spergon ** e e as ea Arasan in!» i *‘I L 640-4 n. L 224 *e es *e *e *e L 640-2 H Tepnotch Golden Wax Spergon as L 224 . as ‘ as in Round Pod Kidney Wax * Spergon e as as as Arasan as * es as as 1,640-h as as as L 224 *i *s as L 640-2 H H F 800d re as Pencil Pod Black Wax Spergon Arasan L 640-2 *** * Significant at 5 per cent level ** Significant at l per cent level a Applied at 4 oz./100 lbs. b Applied at 2 os./100 lbs. c) Close to being significant over the control at the 5 per cent level d) In Plantings IV and V the least increase over the control as compared to the other treatments -22- L 224 seemed slightly better for this variety than Spergon, as L 224 caused highly significant increases over the control in all five planting, while Spergon gave highly significant increases in Plantings I, IV and V and significant increases at the 5 per cent level inPlantings II and III. Round Pod Kidney Wax was benefited by all treatments in Plantings IV and V, and by four treatments in Planting III. For this variety the best performance was given by Arasan, which increased germination sigiificantly over the control in all plantings. Pencil Pod Black Wax showed all its significant increases over the control in Planting IV- There appears here an interrelation of varieties, treat- ments and environmental conditions. It would seem that with a given variety and treatment the treatment gives better pro- tection under certain environmental conditions than under others . A stimulating effect of the chemical on weaker seeds may also be possible, resulting in a higher number of plants emerging. Significant differences between treatments in regard to increases in germination appeared only for Round Pod Kidney Wax. In Planting IV L 224 was significantly better than L 640-4 and F 800, while in Planting V Spergon, Arasan and L 224 were highly significant over F 800. Protectants L 640-4 and r 800 cannot be recasmended for this variety on the strength of these data. The unsatisfactory performance of L 640-4 and l" 800 can be noted from Table 5. These materials caused injury, as indicated -23.. by a decrease in germination in comparison with the control, in a number of cases. The distribution of these decreases over varieties and plantings is shown in Table 8. Table 8.-Distribution of significant decreases in emergence caused by two seed treatments on three varieties of beans at five planting dates Planting Treatment I II III IV V Dwarf Horticulture F 800 as Ra or “E 640-4fi as *4 as F 800 as as as Tapnotch Golden lax L 640-4 4* *4 F 800 *4 ** Significant at l per cent level a) Applied at 4 oz ./100 lbs. All decreases in emergence were highly significant com- pared to the control. Dwarf Horticulture showed a decline only once. From this no conclusions can be drawn. Ranger was injured by L 640-4 and F 800, while Spergon, Arasan and L 224 were beneficial on this variety in all or many plantings . On this basis the question arises whether the benefit derived by Ranger from these treatments might not be due in part to a stimulating effect of these chemicals. A controlled experiment would have to be set up to ascertain the precise functioning of the chemicals. - 24 - Tepnotch Golden Wax was injured by L 640-4 in Plantings I and II and by F 800 in Planting III. An excessive applica- tion of these chemicals may have caused this . Table 7 shows again the toxicity of L 640 when applied at 4 oz ./ 100 lbs. However, its toxicity did not show up in Plantings IV and V, where it was also applied at 2 oz./100 lbs . If it had done so, the evidence would have been stronger. The data are too scant to warrant any final conclusions as to the effect of the environmental conditions prevailing during the plantings on this compound. Emergence Period From Table 10 it is obvious that the emergence period in Planting I was the longest. Both temperature and rainfall may have been responsible for this . The mean tapersture was lower than for any other planting. Planting I was made May 29 and no rain fell from May 23 till June 4; thus planting tool: place during a dry spell. A delaying effect by soil-inhabiting fungi seems unlikely, considering the fact that eventually Planting I had the greatest total germination. On all other plantings rain fell on the date of planting or one day later. The emergence period for Planting III was slightly shorter than for Plantings II and IV, possibly because of the slightly higher temperature prevailing at that time (See Table l) . When the emergence periods for L 640 applied at 2 os./100 lbs. and at 4 oz./100 lbs. are coupared, no difference in the rate of emergence is noted. Table 9 shows the analysis of variance for each planting. -25- Table 9.-Analysis of variance of the emergence period of ten varieties of beans treated.with five seed protectants at four planting dates Error Total £32198 ggg Factor Sum of squares Degrees of Variance 1" freedom Planting I Treatments 43 .38 5 8 .68 7 .55» Vari eties 203 .42 9 22 .60 19 .65" Replications 109 .70 4 27 .42 23 .84** Var. x Treat. 81.58 45 1.81 1.574 Error 271.83 2 6 1 .15 Total 759191 2 Planting II Treatments 13 .06 5 2 .61 6 .21“ Varieties 182 .68 9 20 .30 48 .33“ Replicat ions 5 .19 4 l .30 3 .09* Var . x Treat . 30 .57 42 0 .813 2 .12" Error 2. 2 2 0. Total 1 .02 2% Plantin III Treatments 1 .00 5 0 .20 l .18 Varieties 58 .46 9 6 .50 38 .234” Repli cations 43 .97 4 10 .99 64 .6 5“ Var . 1 Treat . l2 . 52 4S 0 .28 l .6 5** Error 40 .82 25% Total . 2 Planting IV Treatments 1 .10 5 0 .22 0 .88 Varieties 6 5 .67 9 7 .30 29 .20** Replicat ions 141 .49 4 35 .37 141 .48** Var. x Treat. 11.26 45 0 .25 l .0 * Sig'iificant at the 5 per cent level 4” Significant at the l per cent level 4 -26- Table 10.-The average emergence period of ten varieties of beans treated.with five seed.protectants at four planting dates Treatment Variety Control Spergon Arasan 1,640-43 F800 L224 L640-2b Planti I Asg.BI.Val. 15.2 16.3 16.7 16.9 16.5 17.0 Dwarf Hort. 17 .2 l7 .3 17 .8 17 .7 l7 .7 l7 .8 Bountiful 16.6 15.5 1686‘“ 16.4t 16.3 ' 16.3 Asg .Str .Gr.Pod 16 .6 l6 .6 l6 .6 16 .3 16 .6 l6 .4 0.8 440.5 Refg. 15.6 15.1 15.4 16.1 14.9 15.7 Ranger 15 e4 14 e6 15.0 18 02 14e4 1"e8 Sure Crap Wax: 16.6 16.6 16.5 17.6 17.0 17.3 TOpn eGld .Wax 17 e2 17 e 5 17 e7 19 e9 16 e6 18 e 1 End ePOd Kdn .Wax 15 e9 15c]. 15 e3 17 .0 15 e} 16 e0 Penc OPod Bl .Wax 15 04 16 .0 1.55s“. 15 0? 15e9 14e9 Least signifi cant Least significant Planting II A3803 .Val. difference at difference at 5 per cent level 1.3 l per cent level 1.7 10.6 10.4 10.5 11.1 11.5 10.4 Dwarf Hort e 11 .0 11 e4 11 .1 11 e4 11 e4 11 e2 Bountiful 10.1 9.6 10.0 9.8 10.1 9.5 Aug .Str eGr ePOd 10 e} 10 e0 10 e1 10 e4 10 01 9 e8 UOSONOe 5 Refg. 9.5 9e) 906 908 908 906 Ranger 8 e9 8 e8 8 e6 11 e0 9 02 9 e4 Sure Crap‘Wax 10.6 10.9 10.6 10.1 10.3 10.5 TOpn .Gld .Wax 11 .2 11 .5 11 .8 13 .8 12 .0 11 .6 ma ePOd Kdn e"! 9 e4 9 e6 9 e9 10 e2 10.0 10 e0 Penc-Pod Bl .Wax 10 .0 9 .9 9.7 9.7 9.9 9.8 L.S .D. at 5 pct. 0.8 L.S.D. at 1p6te 1.1 Planting III —A'S 0B1 .Val e 9 .0 9 .0 9 .0 9 01 8 09 8 08 D'arf Hort e 9 e4 9 e7 9 e5 9 e7 10 0° 10 e0 Bountiful 8.5 8.8 9.0 8.5 8.7 8.5 A36 .Str .Gr ePOd 8 e6 9 00 9 01 8 09 8 08 8 e9 USeNOeS Refg. 802 Be} 8e5 80‘ 8.2 8e) Ranger 8.5 8.2 8.2 8.8 8.8 8.2 Sure Crop Wax 8 e7 9 e0 8 e7 8 e7 8 e8 9 e3 TOpn .Gld .Wax 9 e6 9 e3 9 e4 10 e5 9 e3 9 e1 Rnd .POden .Wax 8 e8 8 e7 8 e5 8 e7 8 e7 8 e5 Penc .Pod. B1 0'8! 8 e6 8 05 8 eh' 8 e5 8 e4 8 04' No significance for treatments a) Applied at 4 oz ./100 lbs. b) Applied at 2 oz./100 lbs. Table 10( Continued) -27.. Treatment Variety Control Spergon Arasan 14640-43 F800 L224 1.640-210 Llanting LY, A's .31 .V81 0 10 e6 11 e3 10 05 10 e7 10 09 10 08 10 e8 D'arf Hort. . 11 .6 11 .4 11 e4 10 .0 12 .0 11 .3 11 .9 Bountiful 10 .4 10 .2 10 .1 10.2 10 .3 10 .6 10 .2 Asg .S tr .Gr .Pod 10 .7 10 .5 10 .8 10.8 10 .9 10 .8 10 .5 0.3.110. 5 Refg. 9.7 9.8 9.9 9.8 10.1 9.7 10.2 Ranger 10.0 9.5 9.8 10 .4 10.1 9 .4 9.7 Sure Crop Wax 10 .4 10 .7 10 .6 10 .8 10 .8 10 .4 10 .7 Topn .Gld .Wax 10 .3 10 .5 10 .4 10 .8 10 .1 10 .O 10 .6 End .POG. Kdn .Wax 10 .3 10 .3 10 .5 10 .1 10 .2 10 .1 10 .2 Penc .Pod B1 .Wax 10 .1 10 .2 10 .1 10 .2 10 .2 10 .1 10 .0 No significance for treatments _ a) Applied at 4 oz ./100 lbs. b) Applied at 2 oz ./100 lbs. Notes on the emergence periods were taken for Plantings I, II, III and IV. on, in Plantings I and II were the variances for treat- ments significantly greater than the error variances. In Plantings I, III and IV the variance for replications was largest. As the plantings were all made in the same field, this sight show the influence on the rate of emergence of minor differences in soil structure, water holding capacity, depth of planting or other variables. Also the bean maggots may have had some influence here. A In Planting II the I value for replications is signifi- cant only at the 5 per cent level. This planting was spread out over the largest surface and encountered most soil -28... heterogeneity. Of all plantings Planting II received the largest amount of precipitation during its emergence period, and the rain fell intermittently during this time. In Plantings III and IV the precipitation was less and most of it fell during the first week of the emergence periods. As mentioned before, no rain fell on Planting I until six days after planting and the amount of precipitation during its emergence period was low. These differences in precipitation may explain the high significance of replications in Plantings I, III anle, and the significance at the 5 per cent level in Planting II. In these cases where moisture is a limiting factor for germination, minor differences in water holding capacity of the soil might exert a decided influence on the speed of germination. The highly significant P value for varieties in all plant- ings shows differences in rate of emergence between the various varieties. The highly significant interactions for treatments and varieties in Plantings I, II and III indicate that certain treatments acted differently on certain varieties. The reaction of. one variety with a treatment may be different from the reaction of another variety with the same treatment and vice versa. For each protectant the emergence period was determined forty times, except 1.. 61:0 applied at 2 oz ./ 100 lbs ., for which the speed of germination was determined ten times. None of the treatments shortened the emergence period. Arasan, L 640 -29.. applied at 4 oz ./ 100 lbs . and L 224 delayed germination in one or name cases. This is shown in Table 11 in numbers and percentages. The percentages are calculated by adding the significant increases in the emergence period at the 5 per cent and the l per cent level for each treatment, and ex- pressing these sums as percentages of the total times the emergence period was calculated for each treatment. Table ll.-Number and percentage of significant increases in the emergence period, caused by four seed protectants on four varieties of beans at two planting dates Number of significant Percentage significant increases over control increases over control Treatment atlpct. atSpct. level level Arasan l _ 2.5 L 640-4“ 5 1 15.0 F 800 3 7-5 L 224 1 . 2.5 a) Applied at 4 oz./100 lbs. A significant increase in the emergence period over the control must be considered as an injurious effect to the seed. L 640 applied at the rate of 4 oa./100 lbs. was most toxic, followed by F 800. Arasan and L 221; were injurious in one case out of the forty, while Spergon had no harmful effect at all.- ' -30.. In Table 12 the significant increases in the emergence period over the control are distributed over the varieties and plantings in which they appeared. Asgrow Black Valentine, Ranger, Tepnotch Golden Wax and Round Pod Kidney Wax were the varieties affected. Table l2.-Distribution of significant increases in the emergence period caused by four seed treatments on four varieties of beans at two planting dates Planting Treatment I II Asgrow Black Valentine Arasan * L 640-43 w P 800 r s L 224 ** Ranger . L 640-4 ** ‘ as» Topnotch Golden Wax ‘ L 540-4 19* «a F 800 a Round Pod Kidney Wax L 640-1! «- 4* Siaificant at 5 per cent level ** Significant at l per cent level a) Applied at 1+ on ./100 lbs. The rate of emergence in Asgrow Black Valentine seems, under certain circumstances, to be affected by the chemicals applied to the seed. All treatments, except Spergon, caused a significant increase in the emergence period over the control in Planting I. Spergon, too, caused a slight delay in -31- germination, though it was not significant over the control. It may be that this variety was injured by the chemicals due to the dry conditions prevailing during this planting. Treat; ment P 800 increased.the emergence period.1n Plantings I and II so that this compound seemed to be injurious also under the moist conditions prevailing during the emergence period of Planting II. In no case did the chemicals cause a sig- nificant decrease in the number of plants that germinated in this variety. The effect of the chemicals on the seed rather than on the damping-eff organisms is involved.in the emergence period. It can be assumed that the significant increase in germination over the control of Asgrow Black Valentine with Spergon and L 224 in Planting II (Table 7) is due to the pro- tective value of these chemicals against damping-off fungi. However, in view of the increase in the emergence period caused by these compounds in Planting I, the question arises whether the significant increase in germination in Planting II might not be due, at least in part, to a stimulating action of the chemicals on the weaker seeds under the environmental con- ditions prevailing for Planting II. One might expect that . such a stimulating action also would result in a shorter emergence period, but such was not the case. In Ranger a more direct relation between.the number of plants germinated and the length of the emergence period appears. 0n treatment with 1.640 at the rate of 4 os./100 lbs. a sig- nificant decrease in germination from the control (Table 8) and an increase in the emergence period over the control are -32.. shown for both Plantings I and II. It is possible that the compound killed some seeds and delayed germination of others or that the variety is susceptible to damping-off organisms and the delay in germination favored the action of these fungi. Treatment L 640 applied at 4 oz./100 lbs. decreased germination and increased the emergence period for Tepnotch Golden Wax in Plantings I and II. Germination was also de- creased by this compound in Plantings III and V (Table 8), so that, at this rate, it seems toxic for Tepnotch Golden lax. Treatment P 800 increased the emergence period significantly in Planting II for this variety and decreased germination highly significantly in Planting III. Under certain environ- mental conditions a toxic effect of P 800 on TOpnotch Golden Wax seems present. Troatment L 640 applied at 4 «J 100 lbs. increased the emergence period of Round Pod K1dney lax in Planting II . No other detrimental effect of the compound at this rate was noted on the variety. 2mm field is a decisive factor to measure the success of any treatment applied to prevent or control plant diseases. For this reason yield data were taken from twenty plants in each plot in Plantings I, II and III. Plantings IV and V were made too late in the season to obtain a crop. Instead the green weight of twenty plants was taken three weeks after the planting date. The data were analyzed by analysis of vari- ance, but neither yield nor green weight figures showed .3}. significance for treatments. Variety and replication vari- ances were highly significant for the yield and green weight tests, showing the great effect soil differences and the different inherent growth and yielding abilities of varieties may have. It should be kept in mind that, by this method of yield measurement, the direct stimulating effect of the treatment on the plants was tested. Had yield data been taken from all the plants that came up in each of the plots, differences between treatments might have been found. It was noted that in Plantings I, II and III Topnotch Golden Wax treated with L 6140 at the rate of 4 os./100 lbs. showed a consistent decrease in yield compared with the con- trol. In Planting IV there was no difference in green weight from the control, but in Planting V green weight was decreased. The same holds true for Ranger, except that there was no dif- ference in yield in Planting III, while the green weight was decreased in both Plant ings IV and V. Again this is an indi- cation of the toxicity of this compound at the rate of 1t os./ 100 lbs. Discussion and conclusions The snap bean is one of the most widely-grown vegetables, both by truck farmers and home gardeners. They are planted usually two to four inches apart. A heavier seeding involves greater seed cost andadded costs and labor to thin the rows after germination. Any combination of environmental conditions favoring the activity of damping-off fungi would therefore -34.. result in a loss to the grower. Under the conditions of the experiment certain varieties were definitely benefited by seed treatment, while others were not. Little consideration has been given to varietal differences in seed protectants experiments. The above data show that there is a decided difference between the varieties used, and in the interaction between varieties, protectants and environmental conditions. Asgrow Black Valentine was benefited by Spergon and L 22:. in Planting II, but by none of the other treatments. This was the only planting in which germination was increased signifi- cantly over the control by (treatments. In Planting I the emergence period was decreased significantly by all treatments, except by Spergon, which however also decreased the emergence period slightly. Clayton and Nusbaum (4) used the same vari- ety in their trials in South Carolina. They did not find any improvement in stand when the seed was treated with Spergon and Arasan. 11an (18) points out that stocks within the same variety may show a considerable difference in their re- action to seed treatments. The stock used by Clayton and Nusbaum and in this experiment are different, but the data here obtained indicate that under certain circumstances Asgrow Black Valentine is influenced by seed treatment. [core (20) used the variety Stringless Black Valentine and found some benefit from certain treatments under cool weather conditions. A similar interplay of variety, treatments and environ- mental conditions that favored seed treatment for Asgrow Black -35- Valentine in Planting II also was found for Dwarf Horticulture in Planting IV. Spergon, L 640 at the two rates and L 224 increased germination significantly over the control. There was no effect of the chemicals on the emergence period. Ranger was one of the most sensitive varieties tested. Spergon and L 224 increased germination in all plantings, while Arasan was effective in Plantings I, II and III. L 640 used at both rates was also of benefit in Planting V. A direct relation was found between delay and decrease in ger- mination caused by L 640 applied at 4 oz ./100 lbs. Treatment L 640-4 decreased germination and prolonged the emergence period in both Plantings I and II. Two reasons might account for this fact. The compound is toxic to such a degree at this rate that it kills some of the less viable seeds, or, due to the delay in germination, the damping-off organisms have more opportunity to function. The fact that Spergon, Arasan and L 224 increased germination in both these plant- ings of Ranger supports this latter deduction. A stimulating effect by these three chemicals under the environmental con- ditions prevailing in Plantings I and II might also be pos- sible. More data are needed to answer these questicm . Watts and Watts (28) state that the bush type bean is slightly hardier than the manor type. Ranger is a half-runner type, while the other green beans tested are of the bush type. This might explain the sensitivity of Ranger. Topnot ch Golden Wax was benefited by L 224 in Planting III, IV and V and by Spergon in Planting IV. Treatment L 640 - 35 - applied at 4 oz./100 lbs. decreased germination and prolonged the emergence period in both Plantings I and II. There appears a more direct toxic effect on this variety by this treatment at the higher rate, as no other'protectant increased germina- tion in these plantings . Round.Pod.Kidney”Wax was benefited.mostly by seed treat- ments in Plantings III, IV and V. All treatments, except I“ 800, including L 640 at the rate of 2 oz./100 lbs. increased germination in the last two plantings. Treatments L 640-k and L 224 increased germination also in Planting III, Spergon in Plantings II mnd.III and Arasan in Plantings I, II and III. Round.Pod.K1dney'Wax:appeared to be one of the varieties ben- efited.most by seed treatments. Pencil Pod Black Wax was benefited by Spergon, Arasan and L 640 at the rate of 2 oz./100 lbs. in Planting IV. Again environmental conditions prevailing during this planting seemed to favor seed treatments on this variety. Bountiful, Asgrow Stringless Green Pod and.Sure crop'Wax showed no effects of seed treatment at all. Variety U. S. No. 5 Refugee showed an increase in germination once, when treated with Spergon in Planting I. The fact that various varieties show an increase in 9r- mination with some or all treatments stands out clearly in Table 7. The chemicals may stimulate the weaker seeds under certain environmental conditions. (However, one would expect this to be reflected also in a decrease of the germination -37- period of the more viable seeds, but this did not occur. How- ever, the possibility still remains. Optimum environmental conditions differ for the various damping-off organisms. Pythium-caused damping-off is more prevalent during cold weather, while Rhizoctonia and Fusarium are more active during the warm months (3) . Under conditions favorable for a certain fungus, various varieties may be more susceptible to this fungus than others. Protectants enter as a third factor. Due to an interaction between varieties, fungi and protectants, certain chemicals may be more protective to certain varieties than to others. This interplay of in- fluencing factors suggests a fertile field for further study. Had this experiment been conducted only with Asgrow Stringless Green Pod, Bountiful, U. So No. 5 Refugee, and Sure Crop Wax no benefit of seed treatments would have been found. This shows the importance of the use of several varieties for seed treatment experiments. The data bear out the contention that wax beans are slightly more susceptible to damping-off than green beans. Round Pod K1dney Wax was definitely benefited in all plantings by one or more treatments . TOpnotch Golden Wax and Pencil Pod Black Wax also showed some benefits of treatments. Here again variety testing proved its worth. Had only Sure Crop Wax been selected as the wax bean on which to test seed treatment, no benefits would have been found. 4 Under the condition of the experiment (Spergon (Tetra- chlorOparabenzoquinone 98 pct.) gave the best performance. -33.. In 30.5 per cent of the times it was used it caused a sig- nificant increase in germination. Seven of the ten varieties were benefited by it in one or more planting. None of the three varieties, showing no increase in germination with Spergon, was affected by other treatments. Treatment L 224 (Zinc mercury chromate) was next to Spergon in beneficial effects. It was effective in 28 .3 per cent of the times applied and benefited five varieties in one or more plantings . Treatment L 640 (Zinc copper chromate) applied at the rate of 4 os./100 lbs. showed a decidedly toxic effect on Ranger and TOpnotch Golden Wax. When applied at 2 oz ./100 lbs. in Plantings IV and V it caused no injury, but increased germination in 31.3 per cent of the times it was applied. At the rate of 4 oz ./100 lbs. it was beneficial in only 10 .9 per cent of the cases. A test comparing L 640 at the rate of 2 oz ./100 lbs . and Spergon might give interesting and import- ant results. There was some indication in Plantings II, III and IV that L 640 at the rate of 4 oz./100 lbs. acted as a bean maggot repellent. Treatment 1" 800 (2,4,5 trichlorOphenol chloracetate 50 pot.) was injurious to Asgrow Black Valentine, Ranger and Tap- notch Golden Wax. It increased germination in only 4 .3 per cent of the cases where it was applied. It might have been applied at too high a rate. Arasan (Tetramethylthiuramdisulfide 50 pct.) increased germination in 19.6 per cent of the times it was applied. It -39- acted best on Round.Pod.K1dney Wax for which it increased germination tn all plantings. Ranger was the only other variety benefited‘by Arasan. lean temperatures for June, July and August followed closely those of a normal year in.Lansing, Michigan, nor did the precipitation deviate greatly. Under these circum- stances, seven of the ten varieties tested showed some or great benefit from seed treatment. ‘Many varieties of snap bean are grown by farmers and.bome gardeners over a wide range of conditions. Definite recommendations for varieties cannot be made from this experiment,‘but considering the fact that seed.treatment is cheap and.easy to apply, treatment of beans with Spergon seems advisable. Spergon has proved its worth on many other vegetables and no injurious effects fro- it have been reported. If under certain circumstances there is no obvious benefit from Spergon, it should be realized that under more unfavorable conditions real benefit might have been derived. Seed treatment is a cheap and valuable form of crap insurance. ELIE—”£1 Ten varieties of snap bean (Phaseolus vulgaris) were treated with five seed protectants during the summer of 1948 on the Michigan State College farm to test the value of these chemicals against damping-off. Five plantings were made at intervals of two or three weeks to study the effect of various environmental conditions. Under the conditions of the experiment Spergon (Tetra- chlorOparabenzoquinone 98 pct.) applied at 1+ oz ./100 lbs. caused a significant increase in germination over the control in 30.5 per cent of the times it was applied. Seven of the ten varieties were benefited by Spergon in one or more plantings . Carbide and Carbon Chuical Co. L 224 (Zinc mercury chromate) at 4 oz./lOO lbs. closely followed Spergon in effectivaiess. Arasan (Tetramethylthiuramdisulfide 50 pct.) at 2 os./lOO lbs . placed third, while Dow F 800 (2,155 trichlorophenol- chloracetate 50 pot.) and Carbide and memical Carbon Co. L 640 (Zinc capper chromate), both at 4 os./1OO 113-. had a toxic effect on some of the varieties. Treatment L 640 applied at 2 oz./loo lbs. was not toxic and caused an in- crease in germination in 31.3 per cent of the times it was applied. It is recommended that further studies of this compound, at the lower rate, and of L 224 be made. .. net‘sd' -41- 4. Varietal differences in reaction to the protectants and an interaction of varieties, chemicals and environmental conditions were noted. A stimulating effect of some treatments on certain of the varieties seemed present. Variety trials within a program of seed treatment testing would be advisable in future work. 5. In general, the wax bean varieties were more benefited by seed treatments, as shown by an increase in germination over the control, than the green beans, but one wax bean variety (Sure Crap Wax) was not affected by seed treatment at all. 6. Seed treatments were effective for several varieties under various conditions. As seed treatment is cheap and easy to apply, seed treatment of beans is suggested as insurance against Mping-off . 10. 11. 12. 13. -42- Literature Cited Associated Seed Growers, Inc. A descriptive cata10gue of vegetables . New Haven, Conn. 194?. Baker, K. F. Seed transmission of Rhizoctonia solani in relation to control a? seedling damping- off.. PhytOpath. 31: 912-924. 1947. Beach, v. S . Pathogenic and physiggenic damping-off. Soil Science _6_Z_L: 37- . 1946. Clayton, C. N. and C. Nusbaum. Experiments on the use of vegetable seed protectants . So. Car. Agr. Expt. Sta. Bul. 361. 1945. Davis, B. H. and‘C. M. Haenseler. Tests with some vegetable seed protectants. P1. Dis. Reptr. 31: 170- Forsberg, J. L. and A. M. Binkley. The effect of seed treat- ments, commercial fertilizers and minor ele- ments on root rot, stand and yield of pod . p9“ e PhflOp‘th e 21: 650-656 e 19‘? e Gould, C. J. Vegetable seed treatment tests in West Wash- initon in 1943. P1. Dis. Reptr. 21: 594-601. 19 3. . Our experience with seed treatments in Western Washington a riculture. Western Canner and Packer 11%4): 47.49.51. 1945. Halsted, B. D. pring-off. New Jersey Agr. Expt. Sta. 4th Report: 290-292. 1891. Harter, L. L. and I. J. Zaumeyer. Honographic study of ~ bean diseases and methods of their control. U0 B 0 Dept. Agr. Techn- BUIe 868e 194‘. Honfall, J. G. Combating. duping-off. New York (Geneva) Agr. Expte Stan Bale 6830 19380 . Fungicides and their action. Chronica Botanlca GO. I‘lth“, H389. 19‘5e Kotowski, F. Temperature relations to germination of ‘ ' vegetable seeds . Proc. Amer. Soc. Hort. Sci. 323 176-184e 1926e -43.. 14. McCallan, S . E. A. Evaluation of chemicals as seed pro- tectants by green house tests with peas and other seeds. Contr. Boyce Thompson Inst. l5: 91-1170 1948s 15. McNew, G. L. Effect of soil fertility on returns from use of4fungicides. The Canner _9_6_(7): 14.15.42. 19 3. 16. . Value of different seed treatments for lima beans. The Canner 96(8): 14,15,17. 1943. 17. . Seed treatments for spinach. The Canner _9_6_(1l): 18-20, 27. 1943. 18. . Which varieties of peas need seed treatment? The Canner 26(12): 14-16, 30. 1943. 19. . A summary of vegetable seed treatments. The Canner fi( 23): 14-15. 1943. 20. Moore, 1'. D. Studies of certain diseases of snap beans in the Southeastern United States . U. S . Dept. Agr. Tech. Bul. 6470 19380 21. Newhall, A. G. and C. (mupp. Soil treatments for the control of diseases in the green house and seed bed. New York (Cornell) Agr. Expt. Sta. EXte Bul. 2170 1931e 22. Robbins, w. W. Botany of crop plants. P. Blakiston and Son and Co. Philadelphia, Pa. 1931. 23. Seed Treatment Committee of the American PhytOpathological Society. Studies on vegetable seed treat- mefizs in 1943. P1. Dis. Reptr. Suppl. 145. 9 . 24. Seed Treatment Committee of the American Phytopathological Society. Studies on vegetable seed treat- mengs in 1944. P1. Dis. Reptr. Suppl. 161. 19 25. Townsend, G. R. (Revised by G. D. Ruehle). Diseases of beans in Southern Florida. Fla. Agr. Expt. Stae B111. 4390 1947‘ 26. Ialker, J. C., E. J. Delwiche and P. S. Smith. Pea seed treatment with chemical dusts. Jour. Agr. Res. (U. S.) _6_1: 143-148. 1940. 27 . . Ve etable seed treatments. Bot. Rev. L4: 58 -601. 1948. 28. Watts, R. L. and G. S . Watts. The vegetable growing business. Orange Jud Publ. 00., New York. 1940. r. u; '54 ROOM USE ONLY may 12 '54 . v.7 e8.) P .. I . .. .. J. .l: .[:1 ,r. ... . . W243. 1'..wa ,A. . a! w. , 1.... .uh. . . v I