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'. f, {4:}. ‘g‘f’ug‘fh J 730).? 1 V v ‘ b \fis “h. 3 n “ w" I" ”..er . :t‘. ‘ul 1:“: v.32," , , u} ‘37:“: nu; THE INFLUENCE OF SOME AGRONOMIC PRACTICES ON THE PREVENTION OF BLACK-ROOT OF SUGAR BEETS THE INFLUENCE OF SOME AGBONOMIC PRACTICES ON THE PREVENTION OF BLACK-ROOT OF SUGAR BEETS by + 9mm mm NI CHOL A THESIS Submitted to the Graduate School of Michigan State College of Agriculture and Applied Science in partial fulfilment of the requirements for the degree of MASTER O? SCIENCE Department of Farm Crops 1941 ACKNOWLEDGMENT Acknowledgment is due Mr. J. G. Lill of the United States Department of Agriculture, and Dr. C. R. Megee of the Farm Crops Department, Michigan State College, for assistance and guidance in planning and carrying out this work and reviewing the manuscript: and especially to the Farmers and Manufacturers Beet Sugar Association. who pro- vided the funds for the Fellowship under which this work was conducted. TABLE OF CON‘ HTS Introduction Present Status of the Problem Purpose of Problem Review of Literature Influence of Cultural Practices Influence of Fertilizers Experimental Results Muntz Farm (1938) Greenhouse Work (1988-1939) Holgate Merrill Experiment Fertilizer and Seed Treatment Trials Summary Conclusions Page 10 IO 15 28 34 35 luminaries. Damping-off of sugar beet seedlings is a condition apparently caused by the action of certain organisms, resulting in the death of the plants about the time that they emerge from the soil. It is a source of loss well-known to beet growers throughout the world. Losses from damping-off generally occur when the beets are in the seedling stage; sometimes before the seedlings are out of the ground, generally before they have developed their first pair of true leaves, but sometimes even after the crop has been blocked and thinned. Damping-off has also been commonly called: black-root, black-rot, black-leg, and root disease, descriptive of the appearance of the injury which it produces on the roots of the seedlings. Damping-off varies from year to year, between localities, and between fields in a given locality. Losses from it are unpredictable, and may range from a trace up to the destruction of the entire crop in a field. Many experimenters think that the condition may be correlated with unfavorable growing conditions in the spring, such as heavy rain- fall, long periods of rainfall, poor drainage, and low temperature. The impression is that losses are usually greater on heavy soils. During some seasons, it is quite general over a beet growing area. In other years it may be confined to one or two factory districts in a beet growing region. It may almost completely destroy a stand of beets in one field, while an adjoining field may be free from the condition. In other cases, it has been known to destroy parts of a field of beets, killing the beets in one or more irregular patches in the field, or some- times killing most of the beets up to some clearly defined line across the 2. field and doing no damage in the remainder of the field. It has been known to wipe out a stand of beet seedlings, but the same land when replanted showed no sign of damage from damping-off. Damping-off is apparently caused by fungi organisms which are present in varying numbers on beet seed and in all soils, but which do not always affect the beet crop. Three organisms are responsible for most of the losses from damping-off of sugar beet seedlings. They are: Phoma betae, Phythium spp., and Rhizoctonia spp. Phoma betas is always present on shipments of European-grown beet seed, and is sometimes present on American-grown seed. This organism does not live over winter in the soil. except on beet refuse, so the source of infection is always from the use of infected seed, providing a normal crop rotation is followed. Species of Ehythium and Rhizoctonia are found living saprophytically in varying numbers in almost all soils. Coons and Stewart (1) describe the effects of the above-mentioned organisms on sugar beet seedlings as follows: With Phoma betae infection "the seedling shows a browning and blackening of the hypocotyl and root. The discoloration usually shows above the surface of the ground before the seedling topples over. The killing may be fairly rapid or take place so slowly that the seedling seems almost ready to outgrow the disease. Plants are frequently found with hypocotyl completely blackened as far as the cotyledon, which remains turgid and green. Examination of such plants shows the vascular region as the only part not affected. The general impression one has from the examination of such a seedling is that the attack has been made by a moderately rapidly growing organism, which produces a dry type of decay“. Infection from Pythium spp. causes a type of disease "in which rapid wilting occurs, usually unaccompanied by marked discoloration. Such plants have a brown decayed region in the root, and the central vascular region is discolored far in advance of the external lesions. The lesions have a water-soaked appearance as compared with the dry, black lesions characteristic of the 2hgmg_type of attack. Twentybfour hours after the first indications of wilting the seedling is almost completely decayed.” With Rhizggtgnia_infection, "which is not so distinctive in appear- ance as the others, the color of the young leaves gives the first indi- cation of disease. The leaves may be merely deeper green in color, but occasionally they are blue green. Associated with this sign, one finds often a lemonayellow color of the stem. The seedlings grow slowly and, in general, show evidence of malnutrition. On removing the seedlings from the soil, the tap-root is found decayed at the tip and the rootlets above the decayed region are developing, apparently attempting to replace the primary root. No doubt, many of the seedlings thus affected develop into marketable mature beets, but of poor type." This disease is commonly known as "root rot“ or "tap root tip rot". It is first noted as a wilting of the leaves of certain plants in a field during the hot days of mid-summer. If these plants are pulled up it is found that the extreme ends of the tap-roots are rotted off. Many of them have Just enough root system to keep the plant alive during the growing season. Such plants do not develop roots of marketable size. Nuchols and Tompkins (23) described healthy beet seedlings as having erect straight petioles; while beets affected by damping-off organisms had petioles which were distinctly bowed at the base, leaving the plant 4. with an Open type of tOp which was vase-like in appearance. Associated with this was a pale leaf color of the diseased plants. They advocated the educating of beet workers to recognize the symptoms so that they could remove diseased plants and leave healthy ones, at the time of thinning. Most of the experimenters working with this problem have attempted to control damping-off by the use of fungicidal dusts on the seed. Results from this work have varied a great deal and usually no definite conclusions were reached. Some experimental workers have attempted to prove that good cultur- al practices will reduce losses from damping—off. They have been some- what successful in that any practice which will enable air to get into the soil will make conditions more unfavorable for the growth of damping- off organisms. This is well demonstrated by ridge planting, which allows a maximum of air to get into the surface of the soil. There has been an impression that legumes, such as alfalfa and sweet clover maintain some of the damping—off organisms in the soil, and that cultivated crops, especially corn, present a condition which is not so favorable for the maintenance of these organisms. A.limited amount of experimental work has shown this to be true. This fact may have some practical application in the planning of crop rotations which include sugar beets. It has been noted that when beet seedlings were very thick in the rows, it resulted in heavy losses of the plants. This suggested that possibly overcrowding caused a weakening of the plants, and has resulted in some experimental work with heavy rates of fertilization. The results 5. from this work show, in general, that the use of fertilizers, especial- ly those carrying sodium, results in a smaller percentage of loss from damping-off. Present Status 9: the Probleg_ Damping-off of sugar beet seedlings has been recognized for many years as one of the factors which has retarded the development of the sugar beet industry. While considerable research has been made on the problem, many of the findings are contradictory, and as a result, no definite control measures have been recommended. It is quite generally agreed that the three organisms; Phoma betae, Pythium spp., and Rhizoctonia spp. are responsible for most of the losses from damping-off of sugar beet seedlings; the Phoma betae being carried on the seed, while Pvthium and Rhizoctonia are present in the soil. Dusting of the seed with fungicidal dusts usually will cut down on losses from Phoma betae, but will not eliminate these losses entirely. Seed dusting apparently has little, if any, effect in controlling Pvthium and Rhizoctonia. Good cultural practices, meant to increase aeration of the surface soil, works out nicely in the armchair, but unfavorable weather conditions may make it impossible to carry out these plans in the field. The problem seems to be one of making conditions as favorable as possible for the germination and growth of the beet seedlings, and at the same time making conditions unfavorable for the development of the organ- isms causing losses from damping-off. Purpose 9;: Problem The purpose of this work was to attempt to find some control measure, or measures, which a beet grower could apply as insurance that his sugar 6. beet seedlings would not be destroyed by damping-off. No attempt was made to isolate and study the fungi organisms which are ordinarily held responsible for causing this disease. Review 9: Literature Due to inaccessibility of many references, the following review of literature made by Coons and Stewart (1) in 1927, is given. "Root disease, black-rot. or black-leg has long been known as a sugar beet disease problem. In the old literature, insects and soil factors were believed responsible. Hellriegel (7) first called attention to the fungous and bacterial factors involved when by a 20-hour soaking of the seed in one per cent carbolic acid solution he lessened the root- rot. He attributed this effect to the disinfection of the seed ball. The work of Wimmer (16), Wilfarth (l7), and Karlson (9), substantiated this viewpoint. Frank (6) and Kruger (lO), later demonstrated the seriousness of Phoma betae, but the tendency of nearly all of the older research work was to look upon root disease as an indication of some defect in cultural conditions rather than a parasitic relation influenced by environmental conditions. , Duggar and Stewart (4) in 1901, proved that Corticium vggugLB. and c. §9__l_a=._n_l_ Burt. (called by them Rhizoctonia) was capable of killing sugar beet seedlings. Pammel (ll), Selby (15), and Duggar (3) had prev- iously reported Rhizoctonia as causing root-rot in fields of mature beets. European literature for many years has had numerous, more or less intensive studies on sugar-beet root diseases called "Wurzelbrand". In a series of reports between 1906 and 1911, Peters and his associates (12) went over the voluminous literature and from this and their own experi- ments concluded that Pythium debaryanum Hesse, Phoma betae (Oud.) Fr., 7. Aphanomyces laevis do By. were the organisms concerned in the production of seedling diseases of sugar beets in Germany. The German investigators were unable to produce damping-off with Rhizoctonia violocea Tul. In 1915, Edson (5) working at Madison, Wisconsin, found that Eggpg. bgtgg, Pythium debaryanum and Rhizoctonia spp. as well as an organism which he later named fiheosporangium gphanidermatuml. were the principal organisms concerned in the seedling diseases of sugar beets in the United States. Each organism produced a high percentage of diseased plants when introduced into the seed bed. Edson also found Phoma betae present in all lots of seed balls from Europe or America examined, thus confirming the previous results of Peters. Although Phoma is constantly being introduced into sugar beet fields, Pool and McKay (13) have shown that it does not live from year to year in the soil except on fragments of sugar beet tissues. However, Rhizoctonia, and the Phycomycetes, Eythium debaryanum, éphanomyces lgevis, and PythiumIaphanidermappp, are common soil organisms (Jensen (8): Drechsler (2) widely distributed in nature. The problem of controlling sugar beet seedling diseases is, there- fore, concerned with the seed-borne fungus, Phoma betae, and the numerous soil inhabiting fungi capable of attacking beets. It is obvious that since non-infested soil cannot be found for use with disinfected seed, seed treatment at best can be only partially effective. Besides this difficulty, it has been found by several experimenters that treatment of seed to eliminate Phoma betae was not possible. Edson (5), in an attempt to free seeds from Phoma betae, tried three different treatments: (a) strong solution of hydrochloric acid, (b) concentrated 1. Now known as Pythium aphanidermatum (Edson) Fitp. 8. sulphuric acid for one hour, and (c) two per cent formaldehyde solution. Each treatment was used for periods sufficient to injure the seedling without materially reducing the subsequent development of Eggpg; However, Peters' method of pasteurization at 60°F, for ten minutes on two successive days gave one Phoma-diseased plant in about three or four hundred. Edson (5, p. 138) states that this method is not practical for field use, as the germination is reduced. In 1924, Miss Rumbold (14) reported favorable results in sugar beet seed disinfection using formalde- hyde and steam in a sort of combination pasteurization and disinfection system. This method has not come into general use.‘' Coons and Stewart (1) considered that damping-off was of importance to the sugar beet industry in that it caused immediate loss of seedlings, resulting in a reduced stand: and that it was the cause of root—rot which appeared in partially grown beets later in the season. Their investigations consisted of seed treatments with various materials. Wet treatment of beet seed was considered impracticable from a commercial standpoint, because of the impossibility of handling large quantities of seed in this manner. Dusting of the seed, while entirely possible from the handling standpoint, frequently was too expensive because of the lack of assurance that treatment was always necessary to prevent damping-off. Mercury dusts were considered to be especially expensive. They concluded that a mixture of copper and mercury compounds would make a dust which had fair fungicidal properties combined with low cost. They felt that seed treatment might have commercial possibilities after further investi- gations. LeClerg (21) found that beet seed treatment with Ceresan seed dis- infectant in Minnesota not only increased the number of seedlings per 100 9. feet of row, but increased the percentage stand before harvest and the final yield in tons. Leach and Houston (20) state that soil-borne Pythium sp. and Rhizoctonia solani are the most important organisms causing damping- off of sugar beets in Northern California, and that Phoma betae is frequently destructive on seedlings from European grown seed, but has not been observed on seedlings from domestically produced seed. They found that cuprous oxide is an effective seed treatment where damping-off is caused by Eythium sp; but that organic mercury compounds (Ceresan and New Improved Ceresan) were more effective when Rhizoctonia and Ehgma_are involved. This somewhat confirms the observations of Coons and Stewart in 1927, when they recommended that a mixture of copper oxide and the mercury compounds be used for commercial beet seed treatments. Influence of Cultural Practices Coons and Kotila (19) made studies on the influence of preceding crops on damping-off of sugar beets. They found that the amount of damping-off of a beet crop was greatly increased when the beet crop was immediately preceded by a crop of sweet clover or alfalfa. The growing of corn before beets resulted in significantly less damping—off of the following beet crop. A preceding crop of beans did not greatly alter the amount of damping-off. They concluded that "arrangement of crop rotations to avoid intensification of damping-off by alfalfa or the clovers, and to take advantage of its' reduction by corn should lead to improved sugar beet stands". 10. Influence g: Fertilizers A very limited amount of published material was found which stated that certain fertilizing elements had an effect on the amount of damping- off of sugar beet seedlings. One of these articles was published in "Facts About Sugar" (18) from information given out by Dr. J. A. Brock and Col. Gallagher of the Continental Sugar Company. They stated that the addition of NaCl to "diseased soils" resulted in a marked decrease in the amount of damping- off of sugar beet seedlings grown on that soil, and also gave increased yields of beets. No explanation for the decrease in damping-off was given. Lill, et a1, (22) in experiments carried on in Michigan, demonstrated that the application of NaCl to beets resulted in larger numbers of com- mercial roots per acre, larger yields, and more sugar per acre. Chemical analyses of the roots showed that the addition of salt to the soil gave beets with a slightly higher potash content. Considering the higher yield, this resulted in a large increase in the amount of potash taken from an acre of soil. This is apparently true even when there is plenty of avail- able potash in the soil. There is an impression among some research workers that beet seed- lings with a high potash content are more resistant to seedling diseases than those with a lower potash content. Experimental Results funtz Farm - ;g§§ In this problem, the first attempt to control damping-off was made during the summer of 1938 on the Muntz farm at Holgate, Ohio. This was 11. in a field which had been rented by the Farmers and Manufacturers Beet Sugar Association for experimental and demonstrational purposes. One part of the field had already been planted twice, and the stand was destroyed both times by damping-off. A third planting was made on July 7, using untreated commercial seed and using various soil amend- ments, as shown in the following outline. Table l - Plot treatment and rate of application of Soil Amendments at Muntz Farm in 1938. _lPlot Fertilizeri Rategper Acre, 1 Sodium Bicarbonate 700 lbs. 2 _ Muriate of Potash 300 lbs. 3 None (check) --- 4 Sodium Chloride 500 lbs. 5 Sodium Sulfate 600 lbs. 6 Di-calcium Phosphate 300 lbs. The plots were 50 feet long and wide enough to accommodate 76 rows of beets. Fertilizer was applied crosswise of the rows of beets, the materials being broadcast on top of the ground after the seed bed had been prepared and before the seed was planted. None of the plots were replicated. A small amount of damping-off was noted, there being no outstanding differences in the amount of damping off with the different treatments. The check plot was Just as good as those which had received fertilizer. In all cases, plenty of healthy beets were present to leave a perfect stand after blocking and thinning. At harvest time, the fertilized plots yielded more than the check plot, even though the entire field had received a total of 585 lbs. of 12. complete fertilizer per acre in the previous plantings. Greenhouse Work - l2§§rl§§2. In the late fall of 1938, surface soil from the previously described plots at Holgate, Ohio, was sacked and taken to East Lansing for green— house work. This soil was selected because it was known to be thoroughly infested with the organisms causing damping-off. In all greenhouse work, 10-inch pots were used. Each pot was plant- ed with 75 seed balls which had been graded to remove the small seed. The first greenhouse experiment was an attempt to demonstrate the effect of excess water on damping-off. Three pots of soil were made up from each of the previously mentioned plots at Holgate. These 18 pots were divided into three series, each series containing one pot from every plot. One of these series was kept excessively wet, another was kept in a wetter than normal condition, and the third series was kept at about Optimum. This experiment was repeated three times, using the same soil. The following averages indicate the number of plants which had survived at the time the beets had developed the first pair of true leaves. Table 2 - The number of seedlings which reached the two-leaved stage under three different moisture conditions. Replication of Pots Irgatment l_ 2 3 4_ 6 Ayergge Optimum Moisture 91 89 72 85 83 77 83 Above Opt. " 89 82 68 63 71 62 78 Excessive ” 85 57 58 4O 56 55 59 13. It is believed that this experiment demonstrates the value of good drainage in attempting to obtain a satisfactory stand of sugar beets. In another experiment, limed soil was compared with unlined soil. Soil from the Muntz farm was used in this experiment. The soil was placed in 10" pots and 75 graded seed balls were planted in each. Nine pots received calcium carbonate at the rate of 2,000 lbs. per acre and nine pots were untreated. The experiment was repeated on the same soil. so the averages shown below are for 18 pots of beets. Table 3 - The average number of beets which reached the two-leaved stage on limed vs. unlimed soil. WWW 2,000 lbs. OaCO3 / acre 97 No lime 29 It is possible that the amount of lime added to the soil was sufficient to raise the pH of the soil above the point which was optimum for the development of the damping-off organisms. An experiment was conducted, using lime and sodium sulfate in various combinations. The soil was a uniform mixture taken from the Muntz farm plots at Holgate, Ohio. One hundred seed balls were planted per pot. The following tables show the results_of the emperiment. 14. Table 4 — The effect of lime on total number of beets, total weight of beets, and average weight of beets in a total of four pots. Lime Application Total Number Total Weight Average Weight Pounds per acre of Beets (Grams) (Grams) none 904 450 48 o 0503 200 895 54.55 .0611 400 840 52.75 .0628 600 620 53.38 .0861 Table 5 - The effect of lime on total number of beets, diseased beets, and per cent of diseased beets in a total of four pots. Lime Application Total Number Diseased Per Cent Pounds per acre of Beets Beets Diseased None 904 740 82 200 895 396 44 400 840 441 53 600 620 110 18 Table 6 - The effect of sodium sulfate on total number of beets, total weight of beets, and average weight of beets in a total of four pots. Sodium Sulfate Application Total Total Weight Average Weight Pounds per acre Beets (Grams) (Grams) None 631 39.94 .0633 200 819 52.68 .0643 400 892 58.40 .0655 600 9l7 55.24 .0602 15. Table 7 - The effect of sodium sulfate on total number of beets, diseased beets, and per cent of diseased beets in a total of four pots. Sodium Sulfate Application Total Diseased Per cent Pounds per acre Beets Beets Diseased None 631 413 65 200 819 398 49 400 892 485 54 600 917 391 43 The results of this experiment show that the addition of lime was somewhat more beneficial in reducing damping-off than was the ddition of the sodium sulfate. As lime applications increased, the total number of beets decreas- ed, and the weight per beet increased. The higher average weight is . probably due to the fact that each beet had more plant food available for its use. As sodium sulfate applications increased, the total number of beets also increased. This would indicate that the sodium compounds had probably reduced damping-off of the seedlings while they were yet very small and enabled larger numbers of them to survive. An attempt to repeat this experiment on the same soil resulted in no differences between treatments and since it could not be repeated, the value of the results is not too great. Holvate “b An eXperiment. combining salt and lime, was carried out during the season of 1939 in the Northwest Test farm of the Ohio Agricultural 16. Experiment Station at Holgate, Ohio. Four-row plots were used throughout the experiment. Salt and lime were applied at the rates of O, 300# and 600% per acre in all possible combinations. This test was replicated twice. The second part of the test combined sodium sulfate and lime, the sodium sulfate being substituted for salt and applied at the same rate per acre. This experiment was also replicated twice. The following tables summarize the results of the experiment. Table 8 - Showing the stand after thinning on plots receiving salt and lime treatments. Salt Applications Lime Applications in Pounds Per Acre er Acre Average None 300% 600%, None 18277 19060 19908 19082 300# 19583 20104 18799 19495 600% 18669 20235 19844 19583 Average 18843 19800 19517 19387 Table 9 - Showing the stand after thinning on plots receiving sodium sulfate and lime treatments. Sodium Sulfate Applications Lime Applications in Pounds Per Acre Per Acre Average None 300# 600# None 20431 18995 19647 19691 300# 19779 18473 20301 19518 600# 19126 20105 19648 19626 Average 19779 19191 19865 19612 17. Table 10 - Effect of salt and lime applications on the number 9§_beets lost between thinning time and harvest time. Salt Applications Lime Applications in Pounds Per Acre er Acre Average None, 300% 600%, None 9857 10183 11031 10357 300% 9008 7441 5418 7289 600% 5222 5940 7311 6158 Average 8029 7855 7920 7935 Salt applications significant to the 1% point with a difference of 1653 beets. Lime applications not significant. Table 11 - Effect of sodium sulfate and lime applications on the number of beets lost between thinning time and harvest time. Sodium Sulfate Lime Applications in Pounds Applications PeriAcre _£2g;fismg:: None, 300% 600# ‘ Average None 10313 10052 8877 9748 300# 7768 8225 9139 8377 600% 8029 4896 6462 6462 Average 8703 7742 8159 8196 Sodium sulfate applications significant to the 5% point with a difference of 1633 beets. Lime applications not significant. 18. Table 12 - Effect of salt and lime treatments on the number of marketable beets per acre at harvest time. Salt Applications Lime Applications in Pounds Per Acre Per Acre. Average None 300# 600%, None 8420 8877 8877 8725 300% 10575 12663 13381 12206 600# 13447 14295 12533 13425 Average 10814 11945 11597 11452 Salt applications are significant to the 1% point with a differ- ence of 806 beets. Lime applications are not significant. Table 13 - Effect of sodium sulfate and lime treatments on the number of marketable beets per acre at harvest time. Sodium Sulfate Lime Applications in Pounds Applications Per Me _Per Acre None ;_300# 600% <_Average None 10118 8943 10770 9943 300# 12011 10248 11162 11140 600% 11097 15209 13186 13164 Average 11075 11466 11706 11416 Sodium sulfate applications are significant to the 5% point with a difference of 1557 beets. Lime applications are not significant. 19. Table 14 - Effect of salt and lime treatment on the tons of beets per acre. Salt Applications Lime Applications in Pounds Per Acre er A529 Average None 300* 600# None 1.50 1.66 1.83 1.66 300# 2.38 3.43 3.62 3.14 600# 4.90 4.86 3.95 4.57 Average 2.93 3.32 3.13 3.13 Salt applications significant to the 1% point with a difference of .27 tons. Lime applications not significant. Table 15 - Effect of sodium sulfate and lime treatments on the tons of beets per acre. Sodium Sulfate Lime Applications in Pounds Applications Per Acre. Per Acre mone___‘_- 3009 600# Average None 2.77 1.99 2.28 2.35 300# 3.04 2.55 3.00 2.86 600# 2.90 4.54 4.47 1 3.97 Average 2.90 3.02 3.25 3.06 Sodium sulfate applications significant to the 5% point with a difference of .81 tons. Lime applications not significant. 20. Table 16 - Effect of salt and lime treatments on the sucrose percent- age of the beets. Salt Applications Lime Applications in Pounds .Per Acre er_Apre Average None 300# 600% None 14.61 14.88 14.86 14.78 500# 15.69 15.55 15.98 15.74 600# 16.08 17.00 16.56 16.55 Average 15.46 15.81 15.80 15.69 Salt applications significant to the 1% point with a difference of 1.09%. Lime applications not significant. Table 17 - Effect of sodium sulfate and lime treatments on the sucrose percentage of the beets. Sodium Sulfate Lime Applications in Pounds Applications Per Acre Per Acre one____ 300# 600# Average None 15.35 14.58 14.74 14.89 300# 15.45 15.31 15.71 15.49 600# 15.98 15.76 15.02 15.92 Average 15.60 15.22 15.49 15.43 Salt applications significant to the 5% point with a difference of 1.00%. Lime applications not significant. 21. Table 18 - Effect of salt and lime treatments on the purity coefficient of extracted Juice of beets from the treated plots. Salt Applications Lime Applications in Pounds Per Acre ermAgge Average None .300£_~ 600% None 88.57 87.53 87.08 87.72 300% 89.21 87.68 89.83 88.91 600% 88.79 88.97 87.79 88.52 Average 88.86 88.06 88.23 88.38 Salt applications not significant. Lime applications not significant. Table 19 - Effect of sodium sulfate and lime treatments on the purity coefficient of extracted Juice of beets from the treated plots. Sodium Sulfate Lime Applications in Pounds Applications Per Acre Per Acre None 300% 600# Average None 87.63 87.15 86.97 87.25 300# 88.58 88.43 89.13 88.71 600# 89.31 87.62 88.72 88.55 Average 88.50 87.73 88.27 88.17 Sodium sulfate applications significant to the 5% point with a difference of 1.54%. Lime applications not significant. The above tables show that both salt and sodium sulfate gave more beets per acre. higher yields per acre, smaller losses of beets between 22. thinning time and harvest time and higher sugar content. Only sodium sulfate gave a higher purity coefficient of the samples taken at harvest time. Salt did not lower the purity coefficient of the beets. 23. Merrill Experiment A planting of "much beets" was made in 1939, on the Merrill farm of the Lake Shore Sugar Company for the purpose of producing stecklings. Permission was obtained to apply various soil amendments in an attempt to find their value in reducing damping-off of the seedling beets. The area planted consisted of twelve rows of beets, each one-half mile long. They were planted in 24" rows on June 20, at the rate of eighteen pounds of seed per acre. Soil amendments were placed on top of the row after the beets were planted. The materials were distributed as evenly as possible, but since each row was a half-mile long, a perfect job of distribution was not accomplished. After the seedlings had reached the two-leaved stage, stand counts were made on them. In making this count, a stake 42.5" long was placed beside the row. The number of diseased beets in this space was counted as well as the total number of beets. Ten counts were made at regular intervals in each row. Table 20 gives an outline of the experiment, and shows the results of the stand counts. Due to variations in the application of the soil amendments, no definite conclusions are drawr. It appears that the application of salt reduced the amount of damping-off but also reduced the number of seedlings which emerged from the ground. This was especially true of the 300# application. If rainfall had been more plentiful at the time of germin- ation and emergence, it is possible that the heavy applications of salt would have been diluted to the point where they would not have been injurious. Table 20 - Showing the soil amendments used, the rate of application, total number of beets in 425" of row, number of diseased beets in this area, and per cent of disease. Magnesium Per Cent Row Lime Salt Sulfate Total Diseased Diseased _Lbsl_p.r Acre __Beets_inA425" of "ow Buffer 500 100 50 479 4 0.8 1 1500 O O 322 82 9.9 2 1000 100 O 358 31 8.7 3 1000 O 50 399 82 20.6 4 500 200 0 261 11 4.2 5 500 100 50 819 49 15.4 6 500 O 100 393 80 20.4 7 O 300 O 54 1 1.9 8 O 200 50 2i? 16 7.4 9 O 100 100 4§O 28 6.1 10 0 O 150 465 141 39.3 Buffer 500 100 50 337 23 I 6.8 insulin 21‘. 17art 2 DJ and fieed Treetgent Trials -1232 A combination of fertilizer and seed treatment trials were carried '9'! out on the nxperiment Station farm at 1939. F fteen five-row plots, each 336 East Lansing during the summer of feet long, were laid out on soil which had previously received a blanket application of 400% of a 4-16-4 fertilizer per acre: .- These plots received additional fertilizer and seed treatments as follows: Table 21 - Outline of plots used at East Lansing in 1939. for fertilizer and seed treatment work Seed .Plot Treatment Fertilizer per Acre, 1 Treated 50# Borax 2 “ None 3 n u 4 u n 5 Not treated " 6 Treated 400# Muriate of Potash 7 u a n n u + 509% Lime 8‘ " 500# Lime 9 " 400# 44p Super Phosphate 10 Not treated None 11 Treated 400# 447-”. Super Phosphate + 50037: Lime 12 " 500% Lime 13 u 400# Muriate of Potash l4 " " " " " + 500# Lima 15 Not treated None 26. Each plot consisted of five rows, and with the exception of the checks, (plots 5, 10 and 15) each individual row of the plot was planted with seed which had been dusted with a different seed treatment accord- ing to the following plan. Seed Rate of Application Treatment to Seed_ North row Cuprocide 1:50 Second row Copper carbonate 1:50 Middle row 2% Ceresan 1:50 Fourth row Vasco - 4 1:25 South row New Improved Ceresan 1:100 The rate of applica ion and sequence of seed treatments were followed uniformly on all treated plots. A variety of Danish seed was used on all plots at the rate of fifteen pounds per acre, and was planted on May 19. The fertilizer was applied on top of the row after the seed had been planted, the idea being to have a fairly high concentration of fertilizer near the seedlings at the time they emerged from the soil. The purpose of this was to determine whether different fertilizers had an effect on the amount of damping-off of the seedlings. Stand counts were made on the seedlings as soon as it was thought they had all emerged from the soil and also after blocking and thinning. A final stand count was made at harvest time. The figures from this count were used to compute the number of beets per acre as shown in Table 3. While greater differences were shown in the original stand count, it was felt that the final stand count was the better measure of the true worth of the various treatments. 27. At harvest time, all the beets were weighed to determine the exact yield resulting from each of the various treatments. Four samples, each consisting of fifteen average-sized beets, were taken from each row and analyzed in the laboratory for sugar and purity. A summary of the results is given in the following tables. .noHumnodfimnoo Ho mango: and .Aobozon .mmwoqmdamp vo»Moqufi one mm .woaqfioo haddfipow no: mum: mmzHHdoom mg» Had was» poem mm» 0» odd .dfiam> hHoadeo on on dmuouamaoo pod mam wondem one .oommm man nH wmnHHdmom 0009 no nopasa on» mo mesa one: menace can 309 on» ouHmop coowam mm: oxwpm =n¢ 4 .3ou .mmw none cH moomflm know an mace menace Scum dopmadoawo mama mmhfimHm chops one monew oemmmH memem nmmmmH «Hana manna omaoe swanose memmHH mmmoom ammon msasmH mmOHs smanH H oaaH aoom opdnmmoam AoQSm «ea aces mmmsw omsmmH mmHoe mammHH mNOHm mmsmOH H mpaammoem . .HcQHHm was aces memmOH mmmHsH mnOHe mmommH mHmme emmooH m oaHH aoom mmmmm eoemm mHsem mHmmmH emONOH mmmnHH m oqu aoom gasped mo msmHusa aooe HemNOH emsmHH omens omsssH mmmmm mmmHm m amssom mo wpmHnsa *ooe snmmHH anaemH amonHH manomH moema mmmenH H wagon *om ommmm mmmHHH Hemem momma mummn HmHes n oeoz omboe canoe n 282 .nuquqummqullrI[uniquqqmuuuurnquqqmmme.zuumumuq|4raqaamqmmaunlannnumwmnnaunuqmmmuljuqqualnuuuuuuuudluumu dobonmsm 3oz _ mm nomnoo league tumoua mo uoNaHHuuoh mazuzaaama name 02 .oz .tl1 Itllftilzfiiiwwu HA . a .nflirsn lliritl Q. .mnfinafina onowmm opo¢ pom mommm mcwfldoom Mo 90965? wopmHSOHmo on» do mudmsumoua doom can umNHHHpuoh Mo pommmm I mm chaa 29. «$3 Show 88H nHmHm 2.92 HomHm 88H moss: omme Hmsmm oeme nHmHm momsH mmwmm H sang aoom opogmmonm nomsm Ree aooe mnemH mmeom mmmeH omomm nHmsH mosHm H onwaawonm nonsm was aooo mmsmH smmmm smHeH mHmmm mmHsH momom m mafia aoom momHm ammHm emmmH smmmm Hmomm cameo m oeHH aoom nonpom mo opansz aces momHm ammom momom momma smmHm osmHm m season mo asussa.*ooe ommHm mmon momma HmmHm oeomH semHm H mason aom semmH sHHmm mOHmH assmH meomH mmomH n oeoz NOO¢H moowa n odoz .unnmmnnawlaIuannnmmmnnmwuannnnmmmmnn.snmnmnmmwnnarnaamnnuxwu.Illnqqaquuxudaaaquannnnannfiuuuguuquqquuuu: co>OHQMM 3pm “ounce Iougso uuooua mo nouHHHpuoh m name 02 .oz .1- .mquaHna noumd ouqd uom opoom Mo nopsdz vopoHSoHoo on» no mpqoapooua doom was noNHHHpaoh Mo poommm I am oHpoa 30. moosH meOHm a HasmH mewoo mmmsH memom HQNNH mowwosa HHomH moaom mHomH ammom momsH ooemm H maHg *oom opwsmmoam nonsm «as aooe HammH mmsmH smHeH eHsmm momoH ammom H osmagmogm hogan mew «00¢ HammH mmmmm oemmH esmHm camoH soHom m oeHH *oom mHaHm momHm monH manna momom macaw m maHH *oom nmmpom ho a opaHnsa aooe ammom Hmeom mmHom mmmHm mHmHm onsom m season Mo mamawsa-aooe «moon omomH moomm ommom memoH moon H wawom aom nmmmH Hmmoo eomHH «mmoH oHonH omeaH n oeoz Hmmmfl Henna w onoz anIL. .nmmmmmanflIIIIIInmmmmmme:ImnummmmwurInmmmnmquJ.Imqmmqmmom, .ImeHo an no InmnumflIIIIIInnnmeamm doboumsa 3oz . mm. nonmoo Ionmso Ipooua Mo uoNHHHpnoh II. .II» Imwzazaamma gnaw oz .02 IIIII XIII, .III4nnmwdnmwdquunququnamaIw. Innunuuununnnunu .oaHa pmobhom . p4 oped uom mpoom Mo nopEdz uopoaaoaoo on» so mpqospoona doom duo youHHHpnoh mo poommm I fim oapoa 31. + mo.mH mb.mH mm.0H mo.mH mm.HH on.mH mm.0H momoaoa< 3.2 No.2 3.2 8.3 mmHH 3.3 H 33 $8 oponmmomm nomnm was $58 8.2 m3: 2a was: 8.2 8.3 H oponamofi hogan aflw $oov Ho.mH mo.mH ow.m mo.wH mH.HH mm.NH m oqu *oom 8.3 aHaH Hm.HH 85H 3...: 8.2 m 23 doom. amopom mo «.2252 $00... pm.NH om.HH mH.mH mm.mH Hm.wH mp.mH m geopom mo ouoHaszoaoow 0H.mH um.0H mm.mH HN.NH NH.HH mm.mH H Houom *om mm.HH om.mH mm.m mm.NH wm.m mo.mH n oqoz mm.0H mm.0H n oaoz IAnmammmflIaIIIIII4mmnHmmWILIJfiummflfifiI5I4uunnnxwllflammxmmanWIIallnquo duos do>ommmH mom I? mm nommoo Iougso Inooua mo uoNHHHpaoh m92fixaoamaH 3oz . nommoo Ioamso Ipooae no nouHHHoaoh m a gnaw on .02 hl II! .onod mom howdm oapoaobooom mo pqdoad dopoHSUHmo on» no mucospoona doom duo nouHHHpaoh mo poommm I mm oHpoa The experimental data show that the following seed treatments decreased disease losses at East Lansing in 1939: Cuprocide (Red Copper Oxide); 2 per cent Ceresan (organic mercury compounds). Treat— ment with Copper Carbonate gave results intermediate between those of the above-mentioned seed treatments and the check. Vasco-4 (a zinc compound) was about equal to the non-treated plots. Plots receiving fertilizer in addition to the general application were better than those which did not receive the extra fertilizer. Borax appeared to give very good results under the conditions which existed at East Lansing. In combination with Vasco-4 it resulted in almost twice as many beets per acre at harvest time as the plots treated with Vasco-4 without the additional borax. The addition of lime to plots fertilized with either potash or phosphorus resulted in an increase in beets per acre and recoverable sugar over the plots which received potash or phosphorus alone. Tonnage of beets and recoverable sugar per acre were closely correlated. The percentage of sucrose and per cent purity showed very slight variations. The plots receiving fertilizer were slightly higher in quality than those hich received no fertilizer. Summary Some general conclusions may be drawn from the experimental work which was carried out on this problem. The addition of sodium compounds (salt and sodium sulfate) to the soil, in these experiments resulted in fewer seedlings being lost by damping-off: and gave increased tonnage and recoverable sugar per acre without a decrease in sucrose percentage or a decrease in the purity coefficient. Seed treatments with c0pper and mercury compounds cut down on seedling losses at East Lansing i- 1939. The application of borax to the soil at East Lansing indicates that boron deficiency may reduce beet yields very materially on some of our beet growing soils in the state. Lime applications seemed to be slightly beneficial on soil from Ohio which was used in the greenhouse. This seemed to hold true, even though the soil did not show an acid reaction. 35. anclusigns Experience has shown experimental workers that there is no "cure-all" which will prevent the loss of beet-seedlings from damping- off. Control of the disease can apparently be accomplished by the adoption of good cultural practices. Proper drainage is one of the first essentials. (Page 12). Damping-off organisms thrive under wet conditions, therefore it is necessary that the beet grower have facilities for getting excess water from his fields as soon as possible. Crop rotation is another important factor. (Coons and Kotila, Page 9). The rotation should be long enough to allow all beet refuse to decay in the soil, since this refuse may carry the organisms which cause damping-off and other diseases. The recommended length of rotation is from four to five years. I Fertilization is another essential (Brock and Gallagher, Page 10; Lill, et al, Page 10). While most beet soils are naturally fertile, it is profitable to supplement this with additional fertilizing materials. Commercial fertilizers, barnyard manure, green manure and the plowing down of plant refuse are all valuable for adding plant-food elements and humus to the soil. The addition of sodium compounds (Page 14) helps to reduce damping-off but seems to give best results when plenty of other plant food elements are present. Early cultivation, for the purpose of getting air into the surface of the soil, is oftentimes very valuable in reducing losses from damping-off. The dusting of seed probably should be regarded as a form of insur- ance. As yet it cannot be recommended for commercial use, due to the great 36. variations in the results it has given. Summarizing the above conclusions, we note that they are the practices normally followed by good farmers. While these practices may not give absolute control of damping-off in all cases, yet they will reduce it to a minimum. In addition, the adopting of these practices will probably increase yields and net profits sufficiently to more than pay for the extra labor which their adoption may require. 37. LITERATURE CITATIONS Coons, G. H. and Dewey Stewart - Phytopathology, May. 1927, 1. 2. 3. 9. 10. 13. 14. Vol. $311, No. 5. Coons, G. H. Root diseases of sugar beets. Facts About Sugar 18: 158-160, 1924. Drechsler, Charles. The cottony leak of cucumbers caused by Pythium aphanidermatum. Jour..Agr. Res. 30: 1035-1042, 1925. Duggar, B. M. Three 1 ortant fungous diseases of the sugar beet. .N. Y. (Cornell Agr. Exp. Sta. Bul. 163: 339-363. 1899. , and F. C. Stewart. The sterile fungus Rhizoctonia , as a cause of plant diseases in America. N. Y. (Cornell) Agr. Exp. Sta. Bul. 186: 58-61, 1901. Edson, H. A. Seedling diseases of sugar beets and their relation to root rot and crown rot. Jour. Agr. Res. 4: 135-168, 1915. Frank, A. B. Ueber Phoma betae, einen neuen parasitischen Pilz, welcher die Zuckerrfiben zerstbrt. Ztschr. Rubenz. Indus. 42: 904-916, 1892. Hellriegel, F. H. Welche Bedeutung hat die Schadigung der Jungen then durch wurzelbrand (schwarze Beine) and welche Mittel gegan dies Uebel sind bekannt? Deut. Zuckerrindus Jahrg. 15: 745, 1890. Jensen, 0. N. Fungus flora of the soil. N.Y. (Cornell) Agr. Exp. Karlson, Emil. Der Rfibenwurzelbrand. Ztschr. Rfibenz Indus. 41: 371-895, 1891. Krfiger, Friedrick. Phoma betae (Frank) als einer der Erreger von Wurzelbrand der Rfibenpflanze. Ztschr. Rfibenz. Indus. 43: 730- 743, 1893. Pammel, L. H. Preliminary notes on a root rot disease of sugar beets. Iowa Agr. Exp. Sta. Bul. 15: 243-254. 1891. Peters, Leo. Ueber die Erreger des Wurzelbrands. Arb. Biol. Anst. Land. u. Forstw. 8: 211-259, 1911. Pool, V. W., and M. B. McKay; Phoma betae on the leaves of sugar beets. Jour. Agr. Res. 4: 169-177, 1915. Rumbold, Caroline. Sugar beet seed disinfection with formaldehyde vapor and steam. Facts About Sugar 18: 322-825, 1924. 38. 15. Selby, A. D. Sugar beet investigations. Ohio Exp. Sta. Bul. 126: 168-174, 1900. 16. Winner, G. Beitrag zur Kenntnis des Wurzelbrandes Junger Rfibenpflanzen. Ztschr. Rubenz. Ind. 42: 309-333, 1892. 17. Wilfrath, H. Veruche‘fiber den Wurzelbrand der Ruben. Ztschr. Rubenz. Indus. 47: 139-140, 1897. 18. Brock, J. A. Facts About Sugar, Continental Sugar Co., 25: NO. 28. 19300 19. Coons, G. H. and J. E. Kotila. Phytopathology. Vol. 25, 1935. P. 13. 20. Leach, L. D. and B. R. Houston. Phytopathology. Vol. 28, 1938. P. 671. 21. LeClerg, E. L. University of Minnesota Agricultural Extension _ Division Circular 57, March, 1937. 22. Lill, J. G. et al. Journal of the American Society of Agronomy, Vol. 30, No. 2, February, 1938. 23. Nuchols, S. B. and C. M. Tompkins. Phytopathology, Vol. 19, No. 3 March, 1929. P. 317. (I. I ‘1 a fiv.o vanso‘y‘ J‘ J! .. .n 's‘? \"~ '- r a pg: .. "2.5 ~ 7‘.‘, J L ..I' :3»: I. -1. ..‘4 "4‘ I“ I -( 'l I.»- .' r) 5.x” .a , ',.;.’ j i .54 a. x“. ‘c‘. , . './ 't.;; ’hl 3.2? 1‘ (I; ('f' 0 4 / - n P ' . Ilia “30‘5""; .-.( . t - A - ‘ .v' > . t I " 3 pg. 9 3‘ .I.‘\ ? .jy_ 5; 7 .4 ‘ 49 III' I' ll' I'll l l l I II II ' II II III all III II II I II III III 1293 03168 90 3 llllllllillllillllllllll