BULLETIN 253 MARCH 1942 Vetch Varieties for Soil Improvement and Seed Production in Alabama By H. R. ALBRECHT Assistant Agronomist AGRICULTURAL EXPERIMENT STATION OF THE ALABAMA POLYTECHNIC INSTITUTE M. J. FUNCHESS, Director AUBURN, ALA. Contents Page Introduction -- - 1 1 7 9 Evaluation of Vetch Varieties as Green Manure Crops Methods of Planting Vetch for Seed Production Methods of Harvesting Vetch Seed -______________ Insects and Diseases Attacking Vetch -------------------- 11 Summary---------------------------------------L iterature Cited ----------------------------------------13 15 Vetch Varieties for Soil Improvement and Seed Production in Alabama INTRODUCTION increased yields of cash crops which have resulted from turning under winter legumes and the value of these legumes in erosion control (4) have served to stimulate interest among Alabama farmers in winter cover crops. The progress of the winter legume program in Alabama has been extremely rapid; whereas, only 1,500 pounds of winter legume seed were planted in Alabama in the fall of 1918 when the program began, almost 22,700,000 pounds were planted in 1940. It is believed that the progress of the winter legume movement in Alabama would have been even more rapid if seed costs had been lower or if more seed had been produced within the State. The magnitude of the cash outlay for winter legume seed greatly handicaps the program. For example, of the 4,251,270 pounds of hairy vetch seed planted in Alabama in 1940, only 812,970 pounds were home-produced. This means that approximately $320,000 worth of hairy vetch seed alone was imported into Alabama for planting in the fall of 1940. Production of vetch seed within the State has failed frequently enough to discourage many farmers from setting aside a portion of their acreage for seed. The failures have been due to several causes: notably, adverse weather conditions, such as excessive heat during the flowering period or heavy rains during the harvesting season, the lack of adequate harvesting equipment, and the prevalence of destructive insects and diseases. It is also significant that the most commonly grown variety, hairy vetch, is a relatively uneconomical seed producer in Alabama as compared with certain other vetches now available or in the process of development by the Alabama Agricultural Experiment Station. EVALUATION OF VETCH VARIETIES AS GREEN MANURE CROPS THE Bailey, Williamson, and Duggar (2) and Tidmore and Sturkie (5) have emphasized the value of hairy vetch for increasing corn and cotton yields in Alabama. (Figs. 1 & 2.) Although hairy vetch, when adequately fertilized and properly planted, will produce ample green matter to supply the nitrogen requirements of the succeeding crop, most of its growth is made relatively late in the spring (Fig. 3). This, may, in certain years, cause delayed planting of the summer crop which is to succeed the vetch. Sometimes, in unfavorable years when growth is severely retarded, little or no benefit is derived from the vetch by the summer crop which follows. Efforts of workers in the Alabama Experiment Station have been directed toward the development of vetches which will pro- . = r I, *i~ ~/A~'t _ plrttatinjg oiperat1ionIs. Vcetch ,yieldls w\ill increase greatlyv with spit is lelavedi, but it is not rectfiomend~ed that this priact ice ltnig if he followedi sillce( poort standts andi~ contseq(uently- log', yie'lds of the Ithe extrleftt' int yields of the sev'erl reslt. stimmner crop matil ltests conduocted( inl three ge'n(ral sect ions of t he TABLE 1.-Yields of winter legumes tested in three general of Alabama, 1926-1940. sections La unl 1 (1d vetc'h Itiin~ai'iatt vetch Ietch .itiatitha liliiN Ietch' Wilamiette veItcht 7812 60118 88s10 7:t88 87W 590 615 1;92,7 7-1: 880:; 7527 7~ 4:{G6 8500 9:8;8 t1i 6tt19 6198 Vail to 18:817 ttt0 to 176,12 Fail to 290t54 215612 1 5682 700 (Io 11181 7:85 to :82779 Fail to t1751 697 tol 9257 820- 1 W I ,2,1 I;956 88 to A\Iha vetch' Crimon clverVI Aus~trian peas '~iT on e o aly 48 Go Gt 380:t 12.11tt4 7281; % 44881 51;58 1-:to sa d A i 59,4 1197 G;Tttt a di) aP ,112 Nnu ti d ta d in l w vaireties of vettchi rQcordledI in TFable 1 indicate the mini- gree overli yew' 1a0ter (P1hal la periled ofi s. Tw v aria- ly to U athller' con(lit is. H airyv vetch is thei mlost generlally ada;ii)tedl vetch for Alahltiia. It is sufficientlIy haridy anl suiccetds on mosfl1t soil types prllXidl- edl the land is well(Ilainell. H airy is ol1e Ut dr( gh the m111st -Ittt resistanit age U .Ntnot 10 busihels of corn per acre veltches. A seiIuts; dlisialit hairy \elcb is its limOitedi g r U NVt hi durling thbe wiltel. wariie hIvse rmtisfed oae Smootlh Nctth (IV at lasic slag and B)ouInds of njuiate potash per acre. Auburn, April 4, 19 41. adaplted(( (1(0n (i to less p roduc t ivxe lands. Because of its resemb~lance to etchI only certii ed Willanette retch seed should b~e pur- Alla ve ilIike Willamnette, is a variety developed by the U nit ed \tch of Agricturt i e. It is not as \igo romus a grower )prtmeIneit Staite s D as WXillIamoette vetch ( 10ab1e 1), nor is it generally as good a seedi produtcer. Comtnparttd with hairy retch, it is a supteriorl seetder and is earlier in mit urity, but it does ntot consistenttly produice as mitch green matter. Alba \etch is readily recognized by its wvhite flowers. whIiich is a (listioct advaittage from the standpo4 int of certiticat itn Alba vetch, whItich is also a variet v of i urn~ sot 1,0, is hardy enoug-h for use it Alab ama. Like Willamette retch, it is likely to fail on soils of low fertilit. p0010o0/o (Crantz.) is one of the most II tiigariaii etch (Viirtt cold- resistainti vetches tested hy the A labatma I'xperiment Stat ioit. bttt it has ne\ er prtved to be a consistently abuittant protduicer oft gov relatively no-gresv genmatter.I utgarian vetch is er, and( is geiieiall'v a [toor seedl prtoducetr in Alabama. Its use in prieferience to) hairy.,m mont ha, tr Wi ilamette retch is itot recoinmtentetd eveit though ini fatvortable rears wrhen planted on good land it is perfectly capale of Iprodutciitg adequate quantities ot greeit matter. Wool lx'i vtt etch (Vicioi dmlo' cmIrpo Teit.) has not been intc lu ded iin the wiitter legume v ariety tests in recent rears because seed has not been available. Tests conducted by Bailey, Williamson, and Duggar (2), however, indicate that woollypod vetch is sufficiently hardy for all sections of Alabama and that it generally produces more green matter than does hairy vetch. It is about one week earlier in maturity than hairy vetch, has the same range of adaptability, and closely resembles it in growth habit. The selection, Auburn woollypod vetch, now being multiplied by the Alabama Experiment Station shows considerable promise and it will soon be available to the Alabama farmer. It is earlier in maturity than the strain from which it was selected and is a good seed producer. Auburn woollypod vetch grows well during the winter and is outstanding in its ability to produce green matter on less productive soils. Other vetches, such as purple (Vicia atropurpureaDesf.), Augusta (Vicia angustifolia Reich.) and various strains of common vetch (Vicia sativa L.) have been tested by the Alabama Experiment Station, but none are recommended for green manure purposes. Augusta, or native vetch, ordinarily will not produce as much vegetation as either hairy, Willamette, or monantha vetch, but certain strains are now available in commercial channels which are more productive than the native vetch commonly found growing in the wild state. These strains seed well, shatter excessively, and are excellent from the standpoint of their ability to volunteer. They are, therefore, used frequently as cover crops in orchards, or wherever a volunteering winter legume is needed. Another vetch, Vicia grcandiflora, would be recommended more readily instead of Augusta vetch even for this purpose if seed were available. Grandiflora vetch is also an excellent seed producer, shatters severely, volunteers well, and produces larger quantities of green matter than does Augusta vetch even on poor lands. Purple vetch and most strains of common vetch are generally not hardy enough to survive the more severe winters of Alabama. They are also very susceptible to injury by aphids. Common vetch produced in this country is preferred to that which has been imported because it is usually more hardy. As has been pointed out earlier, however, Willamette vetch is the only common vetch recommended for planting in Alabama. METHODS OF PLANTING VETCH FOR SEED PRODUCTION The Alabama Experiment Station has released several publications (Bailey, Williamson, and Duggar (2) ; Tidmore and Sturkie (5); Diseker (3)) giving recommendations for the handling of winter legumes for green manure purposes. These recommendations also apply when it is intended to save the vetch for seed, but certain adjustments should be made to assure maximum seed production. First of all, lower rates of seeding should be used in order that the yield of green matter will be reduced; this is particularly important when conditions favoring dense growth prevail and long periods of wet weather occur during the flowering period. Small seeded vetches, such as hairy vetch should be planted at rates of 10 to 15 pounds per acre, and the larger seeded varieties, such as common and monantha, should be planted at rates of 20 to 25 pounds per acre. These rates of seeding are particularly desirable when plants are grown without support. The rates of seeding recommended for vetch being grown for green manure purposes (20 lbs. per acre for the small seeded varieties and 30 pounds per acre the larger seeded) can be used if the vetch is grown with support. The seed should never be broadcast; plots planted in this manner have consistently failed as compared with those on which seed has been drilled. Tests conducted with hairy vetch suggest that support provided by a small grain favors seed production particularly when heavy rates of seeding have been employed (Table 4). This is probably due to the fact that the grain minimizes the extent of lodging, thus holding the flowers in a drier, more favorable environment, and making it possible to harvest a greater portion of the plant. Wheat, barley, or rye is preferred to oats as a companion crop since oats have too great a tendency to lodge. It should be pointed out that small grain-vetch mixtures are very satisfactory combinations for use in winter grazing. Seed crops can be harvested from such fields if the livestock is removed by April, before the crops are due to flower. When vetch and small grains are planted in association, the harvested seed must be separated if the vetch or small grain is to be sold as seed. Spiral and disc-type separators have proved satisfactory for this purpose when hairy vetch is to be separated from a small grain, but these devices are inadequate for the separation of the larger seeded varieties, like Willamette vetch, from grain. For this reason, it is not recommended that such vetches when planted for seed production be grown with a small grain. However, it is recommended that all varieties be planted in cotton middles so that the dead, erect stalks may lend the necessary support. The number of tests conducted to determine the benefit of support of plants by cotton stalks is limited, but plots on which such support TABLE 4.-Influence of methods and rates of seeding of hairy vetch, Auburn, 1937. on seed production Method Drilled Broadcast Drilled Broadcast Drilled Broadcast 'Average Rate of seeding Lbs. 20 20 10 10 7.5 7.5 Seed yield per acre, pounds Increase due Hairy vetch Hairy vetch to planting alone with rye' Average with rye 145 0 184 22 133 2 223 38 177 57 125 8 184 19 181 40 129 5 78 38 -7 35 -8 4 'Abruzzi of four 1/100 acre plots. rye planted at rate of 40 pounds per acre. was provided to vetch have in every case produced substantially greater seed yields than have check plots on which no support was provided. Rogers and Sturkie (5) found that inoculation of vetch seed and fertilization with phosphate, dolomite and potash were necessary for maximum yields of green matter on a very light, Norfolk sandy soil. They also found it advisable to mix superphosphate or triple superphosphate with the soil prior to planting in order to avoid injury to the inoculum by these fertilizers. The use of dolomite substantially counteracted the lethal effect of phosphatic fertilizers planted in contact with the seed, and it was also determined that basic slag, even when planted in contact with the seed did not injure the inoculum. These experiments were conducted in 1937. The next year, the same plots were again planted in the same manner, but the vetch was saved for seed. Although the seed yields in 1938 were relatively low, it was found that generally the same elements responsible for abundant production of green matter served to increase seed yields. The experiments indicated that potash particularly plays an important role in seed production of hairy vetch on light sandy 'soils. Tests conducted at Auburn suggest that some increase in seed yield of vetch can be expected when boron has been applied to a light, sandy Norfolk soil. METHODS OF HARVESTING VETCH SEED Vetch seed should be harvested as soon as the bulk of the seed crop is mature. Losses of seed accompanying harvest delays are due to excessive shattering of matured pods and to lodging of the crop, particularly during periods of heavy rains and wind. Probably the most satisfactory method of harvesting vetch, whether it is grown alone or supported by cotton stalks or a small grain, is with a combine. (Fig. 5.) Proper adjustment and speed of the combine cylinder are necessary in order to minimize cracking of the seed. The cylinder should be spaced about 3/8 to 1/2 inch from the shelling plate and should not be run in excess of 1,000 R.P.M. On machines which have auxiliary engines, the cylinder speed can be reduced to as low as 800 R.P.M. To further insure against cracking of the seed, particularly when larger seeded varieties are being combined, it is advisable to replace the concaves with blanks. When vetch is planted with a support crop, such as wheat, barley, oats, or rye, it is often necessary to increase the cylinder speed above these rates to accommodate the enormous volume of straw that must pass through the machine. The height of the cutter bar is determined by the condition of the field to be harvested. If the vetch has lodged, the cutter bar must be lowered almost to the ground, but if the vetch is supported either by cotton stalks or by a small grain, it can be run relatively high. The dead cotton stalks will not cause damage to the combine unless canvases are used. However, since higher yields of seed usually result when vetch is planted in cotton stalks, and y 5ILKi.-Comlini haiuy vetch