CRIMSON C L 0V ER i n A lab1)a mna JLLETIN 335 TTEMBER 1961 Agricultural AUBURN E. V. Smith, Director Auburn, Alabama Experiment Station U NI V ERS IT Y CONTENTS Page ADAPTATION --------- 4-------------------- SEEDBED PREPARATION AND SEEDING-4 VOLUNTEER STANDS ---DATE OF PLANTING -------------------------------------------- --- 5 - 6 RATE OF SEEDING INOCULATION 6----------------- 8-------------------- LIME REQUIREMENT9--------------------------9 FERTILIZATION VARIETIES ----------------------- 11-------------------- -- - --- 12----- - --- - - ---- COMPARISON WITH OTHER WINTER LEGUMES-15 Forage Production ---- --- ------ ---G reen M anure------------------ - - - - SEEDING M IXTURES ---------------- - -15 16 -18 -------- ROTATION S M ANAGEMENT - - - - - - - - - - - - - - - - - - - - - - - - - --21--AND USE ---------------------- --------- 22 F ora g e -- - - - - - - - - - - - - - - - -- - - - - - - - - - - - -- - - - - - - - - - - - -22 G reen Manure ------------------------------------- 23 Seed Production ----------------------------------- 23 IN SE C T S - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - -2 4 Beneficial Insects ----------------------------------- 24 Injurious Insects ----------------------------------- 25 C aution -- - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - -2 7 D ISEASE S - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - -2 7 M ajor Diseases in Alabama--------------------------27 M inor Diseases in Alabama--------------------------28 LITERATURE CITED ---------------------------------- 30 ACKNOW LEDGM ENT-------------------------------------31 FIRST PRINTING 5M, SEPTEMBER 1961 CRIMSON CLOVER in Alabama E. D. DONNELLY, Plant Breeder J. T. COPE, JR., Agronomist one-fourth million acres are planted to crimson clover alone or in association with various grasses. This makes it one of the most extensively grown annual winter legumes in the State. An important seed crop in Alabama, crimson is also an excellent winter grazing crop for all types of livestock. It is also used for silage, hay, and green manure. The reseeding varieties will volunteer year after year when fertilized and managed properly. Crimson clover was grown in experiments in Alabama by Duggar (5, 6, 7) as early as 1896. In 1897, Duggar (5) recognized the potential of this legume and wrote "There is reason to believe that crimson clover will prove the most useful of all soil-improving plants for the cotton planter owning suitable soil." He conducted numerous experiments at Auburn and on farmers' fields throughout Alabama seeking methods to grow this crop successfully. Most of these plantings failed because of lack of inoculation. Duggar found that on land not previously in clover, inoculation was necessary for growth of this crop. Inoculum used in early experiments was imported from Germany. Later, soils on which clover had been grown were used for this purpose. In 1909, Duggar published a list of farmers from whom inoculated soil could be obtained for $1.00 per 200-pound sack (7). He recommended that clover be fertilized with phosphorus, potash, and lime and that it be planted in September or October. Duggar recognized the potential of crimson clover for pasturage, hay, and green manure. Since there was little interest in grazing crops at that time, his primary objective was the planting CRIMSON CLOVER is widely grown in Alabama. An estimated 4 ALABAMA AGRICULTURAL EXPERIMENT STATION of crimson in cotton middles to, be turned the following spring for green manure. As a result of the work by Duggar, crimson clover was promoted as a green manure crop. However, it was not as well adapted to planting in cotton and corn middles as were vetch and Austrian winter peas. Therefore, crimson clover almost disappeared from Alabama farms between 1920 and 1985. Because of the excellent growth occasionally made by crimson clover when conditions were favorable, the late Fred Stewart, first superintendent of the Tennessee Valley Substation, in 1984 began a new effort to grow it for forage. He found that early plantings on well fertilized, fallowed land were highly successful in producing early grazing. This led to a. great revival of interest in this crop in Alabama. The advent of reseeding strains of crimson clover in the early 1940's further increased interest in this legume. These reseeding strains made crimson clover much more useful in Alabama's expanding livestock program. This bulletin presents summaries of recent research on crimson clover by the Auburn University Agricultural Experiment Station. Also included is information on phases of clover production on which no research was conducted. This information is based on experience of personnel on the Main Station, substations, and experiment fields of the Experiment Station and observations of Extension. Service workers. ADAPTATION Crimson clover is adapted in all geographic areas of Alabama. It grows best on well-drained, fertile soils. Low or wet soils that are subject to overflow or soils with poor internal drainage, such as Susquehanna clay in the area surrounding the Black Belt, are not suited for this legune. Crimson will not grow on the calcareous or high-lime soils of the Black Belt because of iron deficiency. It is difficult to establish on extremely eroded hills and on the deep sandy soils of central and southern Alabama where it may suffer from drought, lack of nutrients, and poor inoculation. SEEDBED PREPARATION and SEEDING Earliest growth of crimson clover is produced by planting annually on a well prepared seedbed. Best results with new CRIMSON CLOVER 5 plantings result when land is turned 6 to 8 weeks before planting and fallowed. This controls weeds and conserves moisture for germinating the seed and maintaining the seedlings during fall droughts. After turning, harrowing is needed when each crop of weeds emerges. Following the last harrowing, the soil is smoothed and firmed just before seeding. Seed can be planted with a cultipacker seeder, grain drill, or broadcast seeder. About one-fourth inch is the correct depth. Whatever the method of seeding, it is important that the soil be firmed following seeding. When planting in grass sod, a light disking is done before seeding. After seeding, the soil is firmed with a roller or drag. If earliness is not desired, soil preparation with a disc harrow is sufficient following summer row crops. VOLUNTEER STANDS One of the good features of crimson clover is that the reseeding varieties will reseed from year to year. Several strains that have been selected for the high percentage of hard seed they produce are satisfactory reseeders. Grazing is usually 2 or 3 months later on reseeding stands than on clover planted annually on prepared seedbeds. Maintenance of a reseeding stand depends on fertility of the soil, intensity of grazing, competition from summer vegetation, and infestation of insects and diseases. A crop of seed can normally be obtained when clover is grazed provided the animals are removed by April 1 in southern Alabama and April 15 in the northern part of the State. Success of seed production depends on rate of stocking and the season. For reseeding only it can be grazed later if not overgrazed. Overgrazing can prevent reseeding since cattle will eat the seedheads if the stocking rate is excessive. To obtain reseeding stands in Bermuda or other summer grasses, close grazing or mowing in late summer is necessary. If mowed with a sickle-bar, heavy grass residues should be removed from the area. Summer grasses offer serious competition to young clover seedlings for light, moisture, and plant nutrients; and earliness of grazing will be affected by the amount of such competition. Light disking before frost is often beneficial in reducing grass competition and in getting an early stand. 6 ALABAMA AGRICULTURAL EXPERIMENT STATION DATE of PLANTING Planting at the proper time is extremely important for this crop. The following planting dates are recommended: Northern Alabama Central Alabama Southern Alabama Prepared seedbed July 15-Aug. 15 Aug. 15-Sept. 15 Sept. 5-Oct. 20 On pasture sod Oct. 1-Oct. 15 Oct. 15-Nov. 1 Oct. 20-Nov. 15 Late plantings, which usually suffer from fall droughts or early frosts, may produce poor stands or be poorly inoculated. Lateplanted clover grows slowly in the seedling stage and produces grazing only in late winter or spring. Type of seedbed is highly important in determining the best time to plant. Earlier plantings are possible on prepared seedbeds where competition from other plants is at a minimum. Plantings must be delayed on sods or following summer crops that deplete soil moisture in late summer. Seedings should be made immediately before or following good rains if possible. TABLE 1. GREEN WEIGHT YIELDS OF CRIMSON CLOVER PLANTED AT VARIOUS DATES, BREWTON EXPERIMENT FIELD, 1952-58 Date of planting Green weight production per acre 1952 1953 1954 1955 1956 1957 1958 7-year average Lb. Lb. ,Lb. Lb. Lb. Lb. Lb. Lb. 8,000 14,800 5,200 11,900 0 8,200 27,600 19,200 August 20.-----------September 5 __ 27,700 9,300 27,100 16,400 17,200 12,500 6,200 16,600 September 20-.... 29,000 21,900 32,200 12,500 21,200 19,800 18,200 22,100 17,400 28,000 19,400 14,200 19,600 24,000 15,800 19,800 October 5........ October 20-...... 16,800 21,500 24,000 15,100 14,600 16,000 7,700 16,500 November 5...... 10,800 20,100 14,800 12,900 3,600 12,800 8,000 11,900 November 20_.... 16,000 14,100 6,700 5,400 December 5 8,600 1.800 8,600 6,200 5,800 8,600 2,800 10,500 2,800 1,100 9,100 4,900 Data in Table 1 from an experiment conducted on the Brewton Experiment Field illustrate the importance of planting at the proper time. These plantings were made on prepared seedbeds. RATE of SEEDING Seeding rate for crimson clover is dependent on condition of the seedbed. As a general rule, the poorer the condition of the seedbed, the more seed should be used. The purpose for which clover is grown may influence the CRIMSON CLOVER 7 ._ - s °- - ---. _ 5$ .t FIG. 1. Shown is comparative growth of crimson clover in spacings of i,-inch (left) and 6 inches (right) on November 27, 1956, at Mississippi Agricultural Experiment Station. (From Lit. Ref. 9, used with permission of the authors.) seedlin)g rat(' desiredI. Kight and Hllowmell (9) foumd a close relationlship) each xear hetxx ei stand~ dlensity and carix growxth, Fig4ure 1. Cr'imsoni cloy cr in diense stands p;roduced earlier fall and( winter growxth and greater forage Yields than (lox er iln tin stands. These workers fou 1d( in 19.56 that clox er spacedl at 'i inch inlter xals p~rodui ced an axverage of 10,6:34 poltin5 (If green weigfht pracre by ecembher 5, l-ile a siiaxiedfo a 6inch spacing (lid not occur. Unitil Mlarchl 1. Results (of 5 x ears (If research on rate of seeding at the B~rewton and M onl roex ille experimen t fields are presented ini Tab le 2. (loxver in these tests was groxvn for green mnire in an an nuial rotation (ofcorn and Crimson clox er. Corn stalks were disked, seed were sown bx hand, and the area firmed with a ctiltipacker. The seedbeds were not good because (of the large aniotunts of T ABML 2. (1E1i iN WiEIGHiT YIELD tOF NA ii'., BRiEWxTON ANiD MONOIM CRMSeON Li. CiO E SEEDEHD Ai V AB1IlisiS ExieLiuxtFN r FiILS, 1952-56 ~i Year 1952 1953 19.54 1955-1956 AxVFRAGE. Green wxeight yields. at three seedling rates. Bri xxton DIonro x ile 1011b. 2~011). .301lb. 10)1lb. 2)) lb. :3011b. Lb. LI). Lb. LI) Lb. LI). 9,200) 11,800 113500) 8,500) 16,700 20.400 10,800 12,70)0 15.200 II 200 15,500 16,400 .----------------11.80)) 5.700 9.10)0 16.80)) 2x3.800 "12,200 .5,80)) 7.80)) 9),:300 2,7"00 4.500 .5.200 11.70)0 15.70)) 16,.00 17,2))) 25,000 27,00)) 8,600) 11,40)) 1,3,3))0 11,:300 17,100 2) 00 ALABAMA AGRICULTURAL EXPERIMENT STATION cornl stalks on the surface. Each \ ear at both lcations \ ields in~creasedl as seeding rate wxas increased from 10 to 20) to 30 pond per acre. Differences in growxth were greater earlx in tihe sea- son than when x jelds xx ere measuiredl. The reconmnended seeding rate is 20 to 30 p)oundi(s per acre. withl the hihrrte (desirahle. Amount to use dlepenids on condlitimii of the seedbhed. use to he madle of the clox er, price of seed, and coinpaniion crops planitedl wxith the (lov er, When planting -w ith small grain or rx egrass. the cloxver seediiig rate maxr lhe redulced1 to 15 to 20 pondi~s per acre. INOCULATION For hiealthx . x igorou s groxxth, crimnson cloeI li st he p~rope~rly mu inicuilated1 iuire 2. Inoclulants are commercialix av ailab~le for use xxithi clox ers. TJhese are mixtiires that hax e pro)\ed effectixve onl sp~ecies of the leme groupif for wxhiech thex are initended. lie blacteria are disper sed ini a carrier. uisually peat soil, ,xhich is ixied with mioistened seed to bin Ig the bacteria uito conltact xvith the seed. Onice coated wxith iliociillii the seedi should be~ planited as soo011 as possible. In ocu~late'd seed that most be hel 1 for sev eral (laxs before p)lantinlg should he pcjrotectedl from prolonged drxying. heating, or exposure to suinlighut. It is uuuuxxise FIG. 2. Crimson clover must be properly inoculated for healthy, vigo~rous growth. Plot at right was inoculated, that at left not inoculated. uary 3, 1952, at the Experiment Station Plant Breeding Photo was made Unit, Tallossee. Jan- CRIMSON CLOVER to reiy on inoctilt o when the expiration (late printed on the container has passed. W\hile n itrogen- fixing hacteria effectiv e onl clovers are extetisivel d'X(istribu tedl in agrici itinral soils, they b~ecome diminished in soil where clovers are not grown and~ in crease in numbers wber( cloy ers are prominent For this reason proper seedl mod ilatiou is (esential wheni p latin g crimson clox er onl new landl or where clovers hmave nmot recently b~een growni. The small cost is repaidl manyI times ov en in earl ier and1( greater groXth. LIME REQUIREMENT M ost of the soils on whihm crimson clox er is growxn are acid e ain need lime for satisfactory production . Figures 3 and 4. Altliot tgl tolerant of more acid ity than some other legumes, such as alfalfa. swe et clover, ( leX peas ari wh xite clx en, crimson responds to moderate lime applicatiomns on most soils hav.ing a pftl of less than .5.7. The effect of lime on crimson forage yijeldis ini several experiments is presented in Table :3. A soil test is the hest m ethod for dietermningm amonunt ofl ime neieded. Genm erally,. if the soil pH is less than 5.7. lime is needed and should be applied wxell in adX ance of seed in g -about 1 ton FIG. 3. Lime is needed on mony soils for top crimson clover production. This photo, made May 7, 1959, in Talladega County. shows effect of lime. Area in right background had not been limed since clover establishment in 1947. Area at left and in foreground received 2 tons of lime per acre in fall of 1958. 10 ALABAMA AGRICULTURAL EXPERIMENT STATION 4. )A ,~~ft Ii., i T4 FIG. 4. These clover plants are from unlimed (left) and limed areas shown in Figure 3. Plants from unlimed area were unthrifty and had small seed heads, whereas limed clover was vigorous and healthy. Field was grazed until April 15. ace lU Site I 191 11-15 Lb. I ,87 Site' 1052-5:3 I/o 1,856 2. 142 Sit( :3' L)147-1 [0 Site' 4' [((47-- I lh. 12,1201 Site 6' Sit' 3" 1948_0 O 921 1916- 4S 1. 1110 LI). 5,60 LI). 720 20,000 LI). 0 1(60)(1 1.00 1,01; 230(1(10 :3,00 ,0110 83000 453 1,187 4.9) 0 22.600 12:3(00 201,0211 12.040 10.31)(1 tll plot 0 [cck phshteadpoah I lnx( ii inlx sa Noriifolk lomlm lioiilii oilLi sadil) ii illdez Irties i. Fai atOM11iillrs iL'.. Xea in CRIMSON CLOVER on sand e~r\ pcr acre link it c niiucabot sIoils and~ 2 toiis o11 hca\ \-tcxti iltd soils. Ih( oftI I soils that hay c resccediiig stand~s sho1111( l)e dtetr: X cars. FERTILIZATION Crisoncloervv ll rodccsatisfacttoryX Xitits of h)I"t oin soils of1niiitlii fertility proX ided ia food stand isi iSstiil lislicti. I lowxcX (V. it responds to fertilizer as well as to link Ft I . 'i(gi 1111 (rcatest resp~onse to fertilizer andt limei has l)ctii obtainied dii ii i the call\ periodl of grioXXth. I'al\ fall gI-oXX ti is (sp~cciall imiportanit for (grazini bcauise fora es of g'ooti (fi alit\ are osiiallX little "ro~xtl a short timIC. unotil col s prng, whent it lh brwiXidy o tUsC of a soil test is rccoiiiii iCiid to tlctcrini~C tit kindl andi iuooiit of fertiliz'or to usc. 11f soil test is not imad(, '1f) poioids a of 0-14-14 per acrC is si ocstcd for soils jprcXioil" weX f irtiliztd. ll (hl soils that haX c niot l)ccli jpicX ioiisl\ welli fertilized, 100 pouinds of 1- 16-8 per ace is rVcoinihuiCI (d. (IC e lOXCl it)i ahone Ineeds( nol iiitrogCII fertilizCr. IlJiXXcX cr, whe pii1lanitCed cool-seasoni Xithi mrasses, suich as r\ tgrass, resceot, or small gainis, 50 pooundts of n itrogenH pcr acre isnee ihr beor 1 itiio or soo afIi ttr thei-ass conkis iif). llcsCetiIng standts ofi crimlson ci eltX shldt he' fer tiliztd taclh F&, . FIG.~ 5.Ti ~ 93poorp4md ~ tteodAmr Eprmn il hw (fG. 5. cotiste 1923 potgrht adeat the od fetilired Exprlimented.sw 12 ALABAMA AGRICULTURAL EXPERIMENT STATION CRIMSON CLOVER SEED YIELD poundsper acre 40q MEN Auburn Norfolk loomy sand Brewton Kalmialoamy fine sand Hartsell fine sandy loam -Crossville Camden Norfolk fine sandy loom Camp Hill Lloyd clay loom Tuskegee Boswell clay FIG. 6. Effect of applying 10, 20, or 30 pounds of borax per acre to crimson is illustrated by these seed yields on six Alabama soils during 1950 to 1954. No yields were obtained from Camp Hill in 1953-54, Camden in 1954, and Crossville in 1955 because of drought or early freeze. (From Lit. Ref. 11.) fall with about 300 pounds of 0-14-14 or every other year with twice this amount. Failure to fertilize adequately will result in loss of stands on most soils. Borax at 10 pounds per acre is required on clover grown for seed production (11). This is especially important on sandy soils. Experiments on four sandy soils showed large increases in seed yields from 10 pounds of borax, Figure 6. However, clover on the two clay soils did not respond to borax. Forage yields were increased when the soil was deficient in boron. In most cases, however, vegetative growth was not affected by borax application. VARIETIES Common or commercial crimson clover has been tested by the Auburn University Agricultural Experiment Station since before 1890. Reseeding strains were selected in the early 1940's and caused greatly increased interest in crimson clover. Many reseeding strains resulting from natural selection or survival have been grown in Alabama. Seven of the most popular varieties have been tested in recent years by this Station at three locations. Seasonal forage distribution was determined by clipping several times during the season, Table 4. In a second test at each location, the varieties O z A 7v 0 m TABLE 4. YIELD OF DRY HERBAGE PER ACRE PRODUCED BY CRIMSON CLOVER VARIETIES SEEDED ANNUALLY MORE TIMES DURING THE GROWING SEASON AT THREE LOCATIONS AND CUT Two OR Alexandria, northern Alabama Variety 3-yr. av. Total Early growth growth Lb. Lb. 1 Tallassee, central Alabama 3-yr. av. Early Total growth growth Lb. Lb. 1,686 2,009 1,548 976 1,773 1,888 3,262 3,475 3,292 3,090 3,564 3,705 1 Brewton, southern Alabama 3 4-yr. av. Early Total growth growth Lb. Lb. 1,192 927 635 978 749 568 2,301 2,495 2,214 2,240 2,395 2,069 2 5-yr. av. Total Early growth growth Lb. Lb. 1,448 1,741 1,331 1,055 1,507 .. 3,837 3,925 3,815 3,795 4,017 2,554 1,336 Auburn ........... 2,658 Autauga......... 1,247 925 2,885 Chief 565 2,534 Common........ 2,579 Dixie -...-.. 1,010 873 2,794 Kentucky ......... Talladega _....... 506 2,329 1 1956-58. 2 1955-58. S1952, 1953, 1956, 1957, 1958. 3-yr. Early growth Lb. 653 708 437 555 516 459 470 av. Total growth Lb. 2,174 2,387 2,640 2,799 2,401 2,504 2,612 1 4-yr. av. Early Total growth growth Lb. Lb. 640 390 515 505 401 465 1,981 2,141 2,282 1,988 2,077 2,166 w 14 I '.iis ,E ALABAMA AGRICULTURAL EXPERIMENT STATION 5. '1111 ) o1, HII xx IS THlE Atn 01.Pttili) (1 1 AT iuN (.~oyN( CLtiN , VAI oz 11,. CIT ONCE HAY STA(,l. IM 111, hI' \iNS niorther n Alabamva 4-N r..3-vr.' cciiti 3 i.' . Alauu i 6-\ i.' 4- .i LI). .3,67) .662 :3.150) .3.710 1.1. 3,759 :3,634 :3.7W) .3,955 southcriui Alabamai 4-xr. .3xr.' Lb. \iihiiri Aiitaiii~ .3,681 3,756 LI). 3,29)4 3.215 3,401 3,1-15 3,:357 Lb. 3,8.37 3,828 .3.7 18 :3.1534 LI). 2,768 2,903 LI). 2,68;3 2.939 :3,094 Chieft (>hiniou 3,844 3,548 3.1)31 3,018 2,602 D),xi Kiitink} I fllatcg ''3,671 3,48.5 .3,9,9 .848 .3,110 2.87 3.316 :),115 :3191 19.56-58. 1t954.19.56-58. 1951, 1952. 1954. 1956-58. w~ere cut only once when most varieties wxere ini full bloom. 'fable 5. Aiubnurn, Aurtauga, and D( ixie are earlier to reach fiuil1 flower than. Talladega, coifmme rcial, C:hie~f, and Rem ickx , Tal e 6. There is an 8- to 10-dav spread1 in matumrit\ amnong (v'arieties. The eal-flowvering varieties geeal poue morecapfr age thant the late-floweringf ones, Figrm me 7. 1Iowv er, the nagnituude of the difference among \ arieties ill earl forage producttion4 varies from v ear to \ ear an~d is inmlu ~eed b)\ suhl factors as (late of planting, soil moisture, teumperatmure, and stanid. (See chapter on Rate of Seeding. 1 Ch ief, conlmuni , Tlalladega, andl 1\.m tmme gen erally p)roduhced the most forage w\hent cut onl- once at the hay stage (fuil bloom 1 FIG. 7. Common (left) and Autaugo varieties show differences in early growth. Photo was made March 2, 1959, at Plant Breeding Unit, Tallassee. CRIMSON CLOVER I BILL 6. \ AHIArloN 1S D-IL oi l 111I AMrONG CIMSl~ON CLOVE VRITIIILSL. 195~9 Tallassee, centralI AilabamaI D ate of Da te of Alexandiai, northeurn AlabamaI~i aiet' 0 Date of Apil 20 Apri1 20) April D atc of 11(1 1)101(1readiness \1nty11 \1i' 1 \la\ 11 A\lu 15 \1ia 18 Alii 18 20) April 26t Apri1 24 April 28 \iuil I 1 Apil 5 Api i April (6 :Apil 8 Mi 9 \1ax 12 Mil ['3 Mal 15 Mayx 16 D iffercnces in) total produ ictioni ainouig \ arictics we rc sm mo1st cases. Thlcse data indicate that Aubhun, D~ixie arc slighltl\ sutpeior for cadl\ produIctionl. COMPARISON with OTHER WINTER Forage Production all ini \ltaipra, and1( LEGUMES Cr~imo el I 51 .o r is ani ecellent forage lcghln Ic. Its popuIlarity in recenit \ cars has beeni Iargcl\ becaulse ol its iiscf iiiss as a forage, Figure 8. It has bccn comparcd cxtelsiy\ w xith other foragc legtimcs bx this Stationl sincc 195:3. Langford (1 0) reportc(d that crimson cloxvcr produllced carhcer and mnorc total foragc than anix othcr wxiniter lcgume tested. Table 7 presclnts thc relativec INA M . a 06 -# ~,,,-4 FIG. 8. Crimson clover is an excellent grazing crop for hogs. The shown here was photographed in Autouga County in April 1959. field scene 16 ALABAMA AGRICULTURAL EXPERIMENT STATION 16 ALABAMA AGRICULTURALEPRMN TTO TABLE 7. RELATIVE EARLY AND TOTAL YIELD OF OTHER WINTER LEGUMES AS COMPARED TO CRIMSON CLOVER, 1953-56 (FROM LIT. REF. 10) Crop and number of testsFRhave -- Tl Pct. 100 5 Pct. 100 71 Crimson clover--------------- - Ball clover, 18-1772----Kenland red clover, 12-----------------------Rose clover, 54--7----------1 Mike clover, 12257---------La. S-i white clover, 10-8 Button clover, 13 Subterranean clover, 76----0----Hairy vetch, 18 ---- 1956-----85 57-----------------88 yields of Ball, Kenland Red, Rose, Mike, La. S-1 White, Button, and Subterranean clovers and hairy vetch when compared with crimson. Hairy vetch was the only legume that compared a forage. The favorably with crimson clover in performance other legumes grew much more slowly in the fall and winter and produced growth much later than crimson clover and vetch. Total production was also lower. as Green Manure Since crimson clover was brought to this country from southern Europe about 1819, it has been highly regarded as a soil builder. It was used primarily as a green manure crop until recent years when livestock farming became important in the Southeast. How- ever, larger soil building since they are generally easier to establish and require less seedbed preparation following row crops. When good stands of crimson are obtained, it compares favorably with the other legumes tested for green manure. It has produced about the same amount of growth as hairy and Monantha vetch, and more than Austrian winter peas, Table 8. Auburn Woollypod vetch produces earlier and more total growth than crimson clover or the other vetches. Crimson clover compares favorably with Warrior and Willamette vetches as a green manure crop. As a green manure crop, crimson clover has also been compared with and found superior to' Hungarian, Oregon (common), and Monala vetches; Caley, Dixie Wonder, and Papago peas; and blue, white, and yellow lupines. These crops were inferior be- seeded legumes such as vetch are better suited for A CH 0 z n r- 0 m TABLE 8. GREEN WEIGHT PRODUCED BY FOUR WINTER LEGUMES GROWN FOR GREEN MANURE, SEVEN LOCATIONS' Legume Tennessee Valley Substation 1931-45 (13) Lb. 17,200 Sand Mountain Substation 1933-45 Green weight per acre at seven locations Wiregrass Alexandria Aliceville Monroeville Field Field Field Substation 1994 1914 1915 19-1 Brewton Field 13-1 Weighted avrg (11) Lb. 12,300 1939)46 (5(1) Lb. 7,500 13-4 Lb. 9,200 (193151 191-1 (1(2)2) Lb. Lb. 13,800 8,600 (1931-51 Lb. 8,700 0ag Lb. 11,100 Crimson Hairy vetch___________________ Monantha Austrian winter clover -------------- vetch ------------peas ---------- 12,000 12,700 10,500 7,600 7,800 5,800 15,200 21,100 15,300 7,200 8,000 6,700 13,800 17,000 8,300 7,100 7,000 3,400 6,100 6,300 5,000 __ 9,300 10,400 6,800 I~Y( I~ ~~ l~L YIOY ~~l J ~ Numbers in parentheses are the number of years tests were conducted. ALABAMA AGRICULTURAL EXPERIMENT STATION FIG. Crimso mn ~ is cattle ~ w or l ~ 9. d rzn pe 4 o rmo s n lvri ocad nA o rzn tuoCut n re ea r Her orcard Te potorah ws mdeAprl cals of 160 od o-rdcinanprSICpiiitt iess sllpll 9. Cem.,na itr e f-uaat o nor c ord mrjnuremaHeriale wlontgazing cbrmson o er orhard the photograph ass mae Apirilrc 960.l 1otn trors gor end all hei enAtag Cnityen) i 3)t . ercenof Al t(Ie Celo tha maoocteii alI~ ite an or Sius contin l tu-rc ed oe c-o ( n pier-e (rel o r for nue thlat~e ohr\ ner.(lns lcuoe Crimsonl croes of Will p(cntaenlr othe eochars, thFitrel . no nreed ato eilofl-lpilfo e eelleto~e tea tes oluei Xx Iiutr eglle per dest Itt I itroi IS alaowed su to es.5 o becoltI')teI av)r- SEEDING MIXTURES Inc(leased idl ( andU loligel "ra~/ilt 1( cloX (r ill mlixturles plal Itil(g erl 11501 ter '(lasses, Fi'ffll' 1(0. Although~rh seasonI call be obitained b\ wXithI adlaptedl anna1 Xinwbd loat illcattle is less co)llnloI o1ilcilnsoll thlan 01n XXIite c-lox er, its inceidenice caln be (greatIx r '(ed d b\ ~ ra s ug c c wi th c-lox er. ue plalutil e grass a s a d s Som e grasses u s al g i s coIIIII~oIIuIXr e t CRIMSON CLOVER 19 yros mixtntFIG. 10 [Beef cattle make good gains on crimson clo. These cattle were on clover-grass pasture in Autauga County in April 1960. - 111(1 r- (. iiatioiis Besiilts (of se\ (ial e\)erilmeInts imi olxill" X ariolis 1 of, these are p)resen tedl in Tale 9. (0111b)- at abllit the AIIIIIIAl ln (rass 'ld~ rescileg(ratss seedllill~gs (c lop(i)j loTr. ( ra/inig call he miiathose of1 crilsoll cm salve rate as (d( tailied later ini the spriulg l\ lushig, these g;rases With crinlsoil to tihe mixiturle ('ither before or . clox er and( apl)l ink iitrogeli sooll alter p)lan tinig. hlesctiegrass is suisceptib~le to lildlex and( solle xears. ich iiiax seriollsh\ redulce x eldk inl sinut. whl Smnall gainis with crimsoni cloxver p~roduie miore carkX grrtiig thlan rx (girass or. reseliegass wxith crimlsoni (loxver. I~e ( (roĢ,s eIA miore rapidlx ini the fall than xx ha or oats. Sin ce rxc iaties the s1)1ilig( earlier, it is less Col11 1 )etiti\ e thati whciat and( oats ill d11lilli the periodl of maost rapid (loxcr (groxxtl. Smiall gratiils are the miost dIepend(alie crops ax ailahle for prodlicii fall anid sxiniter girailefr Becau se of comlpet ition f roin tihe sohall(ran erloes inot coitiilite iiuncih to the fall ail1(1 Toitei' crilisolil ci it Iixtu m1(1 res, 1)hiltaddsL to the foirm~e fomg prodnuc((l fromi snI the sprinig. The lonicst gi-ratinig seasoni is obtajined produced ili er, FiguIre I I. n rxgass. and~ crililson (Clm with a mIixtulre of i'x, Small gains and~ I-v(glass sh101ll iiot b~e seeded( at higrh rates wheni planited xxithl criliso clx er because the conipc)titioll ill crimsonl chlxer earLv groxxth stags ma prex eIlt a good stanid ofl Small grailns 111a\ be~ ixied to gixg( better dlisfronii Sunx i i. 0 TABLE 9. YIELDS OF CRIMSON CLOVER, SEVERAL WINTER ANNUAL GRASSES, AT SEVERAL LOcATIONS, 1953-5712 AND VARIOUS COMBINATIONS Dry forage produced per acre, seven locations Crops and mixtures Wiregrass Substation 1955-6 (1) Lower Ctastal Plain Substation 1953-6 (3) LowerTper Coastal Piedmont Plain SubstationSValey Substation 1953-5 (2) 1956-7 (1)61953-6(3) 19ubstation Lb. 7,136 7,362 6,923 5,852 VTennesseeaUp SMain 55-61)(1) Coastal bPlainn eI- location r Lb. Ryegrass-crimson clover______________ Ryegrass Rye-ryegrass-crimson clover Rye-ryegrass Abruzzi rye 2,959 Lb. ____ Lb. ' Lb. Lb. 6,021 Lb. 2,840 Lb. 4,775 3,060 5,939 4,366 7,437 4,115 4,622 3,486 -------------------------------------- 4,120 3,662 2,510 3,812 7,463_ 4,801 3,428 ------ ---------------------------3,409 3,634 __ 2,589-1,152 5,136 7,147 3,725 ______________----------------- 3,139 5,400 4,373 Oats______________________ _________ Oats-crimson clover Oats-woollypod vetch_________ Crimson clover --------------- 3,655 2,859 2,495 2,416 4,649 3,186 7,255 _____ 5,914 Rye-crimson _____ __ __ 4,378 4,318 4,249 4,413 4,479 ___ ___ __ ___ ___ 4,642 4,521 5,409 4,839-4,519 _____ -, __ 3,263 2,172 2,464 ----- C C 3,905 _4,613 3,380 2,954 Wheat-crimson clover________ clover____________ --'ala -m W heat Rescue-crimson clover ------------------------------ _-__-__ x z -- 3,081 --- 4,039 ----- 3,285 m m data from W. R. Langford, formerly of the Department of Agronomy and Soils, Auburn University Agricultural Unulse Experiment Station. 2 Numbers in parentheses are the number of years tests were conducted. z CRIMSON CLOVER 21 21 CRIMSON CLOVER FIG. 11. The graph shows seasonal distribution of forage produced by crimson clover, crimson-ryegrass, and crimson-ryegrass-Abruzzi rye and total forage production for each. Data are from six Alabama locations during 1956-57. tribution of grazing and to prevent excessive competition at any one time. Recommended seeding rates for mixtures. containing crimson clover are: 20 20 20 15 pounds pounds pounds pounds crimson clover, 20 pounds crimson clover, 25 pounds crimson clover, 80 pounds crimson clover, 15 pounds pounds oats, wheat, or rye ryegrass rescuegrass oats, wheat, or rye ryegrass, 60 Crimson clover and ryegrass seed should not be planted as deep as small grain. They can be seeded with a grass seed attachment on a grain drill or in a separate operation following planting of the small grain. ROTATIONS Cropping systems that are adaptable to use with crimson clover depend on utilization to, be made of the clover. Several 1-, 2-, 22 ALABAMA AGRICULTURAL EXPERIMENT STATION and 3-year rotations for use with crimson clover for grazing and for seed production are suggested below. Reseeding Crimson Clover for Grazing or Seed Production 1-YEAR ROTATIONS Crimson clover-Coastal Bermuda, common Bermuda, or crabgrass Crimson clover-millet, Sudangrass, or grain sorghum Clover Planted Annually for Grazing or Seed Production 1-YEAR ROTATIONS Crimson clover-millet, Sudangrass, grain sorghum, or soybeans 2-YEAR ROTATIONS Crimson clover-grain sorghum-small grain Crimson clover-soybeans-cotton or corn 3-YEAR ROTATIONS Crimson clover-grain sorghum-vetch-corn-cotton Crimson clover-grain sorghum-small grain-soybeanscotton or corn Crimson clover-grain sorghum-vetch-corn-small grain Crimson Clover for Green Manure 1-YEAR ROTATIONS Crimson clover-corn 2-YEAR ROTATIONS Crimson clover-corn-cotton MANAGEMENT and USE Forage Crimson clover normally makes most of its growth in late winter and early spring. However, it grows rapidly when planted in early fall if moisture is adequate. It makes little growth during cold periods in winter and should not be overgrazed, especially under these conditions. Removal of all of the leaves will reduce the rate of recovery. Since this plant starts from a small seed each year, it has little or no root reserve of stored food to promote new growth after close grazing. Grazing should not be started until clover is 4 to 6 inches tall and it should never be grazed below 2 inches. This will often mean that livestock must be removed if the stocking rate is high or during periods of slow clover growth caused by cold or drought. Although used primarily as a grazing crop in Alabama, crimson clover makes excellent hay when cut at the early to full bloom stage. It is not often cut for hay because it reaches the hay stage during a period of frequent rains and when farmers CRIMSON CLOVER 23 are usually busy with other crops. Crimson cures slowly because of a high moisture content and the season of the year. It makes excellent silage. Green Manure Annual winter legumes, such as crimson clover and vetch, are used widely for green manure ahead of corn. They may be used ahead of cotton if sufficient growth is made early enough to turn 2 or 3 weeks before cotton planting time. Early planting is desirable although not as essential for producing green manure as for grazing. A good growth of green manure will produce as much corn as 60 to 90 pounds of commercial nitrogen (4). Corn needs no additional fertilizer when following a good crop of legumes properly fertilized with phosphorus and potash. Crops following green manure should not be planted for 2 weeks after turning because of danger of damage from certain insects. Obtaining a good stand following a row crop is easier with vetch than with crimson clover and less seedbed preparation is required. If planted early enough to produce fall or winter growth, these crops may be grazed and still produce green manure by removing livestock in early spring. If needed for grazing, clover is worth more as forage than as green manure. Seed Production Production of good seed yields under Alabama conditions is another reason for the importance of crimson clover. If grown for seed only, early planting is not as necessary as for grazing. However, other phases of management are important. Thin stands often result in excessively high weed seed content. Seed yields will be greatly increased on most sandy soils by applying 10 pounds of borax annually (11), Figure 6. When used for both grazing and seed production, cattle should be removed by April 1 in southern and central Alabama and by April 15 in northern Alabama. The time to remove cattle may vary with season and intensity of grazing. Beneficial and harmful insects may greatly influence seed yields. Bees are needed to pollinate clover. Clover head weevils must be controlled if good seed yields are to be produced. These factors are discussed in detail in the section on insects. 24 TABLE 10. ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF SEED MOISTURE CONTENT DURING STORAGE ON THE 1 GERMINATION OF CRIMSON CLOVER SEED Initial seed moisture content Initially After 4 months Germination After 1 After 2 year years After 3 years Pct. 14.8 12.3 10.I - Pct. 30.0 90.0 93.0 Pct. 85.0 94.0 Pct. 11.5 86.0 Pct. 00.0 68.0 93.0 93.0 93.0 1 Unpublished data of H. S. Ward, Jr., formerly of the Department of Botany and Plant Pathology, Auburn University Agricultural Experiment Station. Seed are normally harvested direct with a combine when most of the seed heads are fully mature and the seed can be easily stripped between two fingers. Excessive wind or rain at this time can cause severe or total loss of seed by shattering. After combining, seed should be taken to, a cleaning plant for removing green material and drying. If heated air is used for drying, the temperature of the drying air usually should not exceed 1100 F. Germination of seed after storage is dependent on seed moisture content, storage temperature, and time in storage. The effect of various seed moisture contents during storage on the germination of crimson clover seed is shown in Table 10. The safe moisture content for crimson clover seed stored in Alabama is 10 per cent. INSECTS Beneficial Insects When crimson clover is grown for seed, it is important that bees be present for pollination, Table 11. Results of experiments by Blake (3) show that honey bees placed in or near clover TABLE 11. YIELDS OF CRIMSON CLOVER SEED PER ACRE IN THE ABSENCE OR PRESENCE OF HONEY BEES, 1951-52 (DATA FROM LIT. REF. 8) Seed yields at three locations during 2 years Treatment 1951 I Lb. II Lb. 7 92 601 509 III Lb. 40 575 535 I Lb. 19 300 281 1952 II Lb. 177 1,196 1,019 III Lb. 49 808 259 Bees excluded Bees present Increase - - 157 5411 84 CRIMSON CLOVER 25 fields will cause increases in seed yields, if the potential yield is high as a result of other good practices. Two colonies of bees per acre of clover are recommended. If the clover is well fertilized, moisture is not limiting, and cattle are removed early for good growth, three colonies of bees per acre will prove profitable. The bees should be placed in or along edges of the field, preferably in shaded areas, so the flight distance is as short as possible. If the clover is not to be harvested for seed but is expected to reseed the next fall, bees are still needed to produce enough seed for the volunteer crop. Less than one colony of bees per acre will be enough under these circumstances, and in many areas, wild bees will be sufficient. In areas where there is a dearth of both wild and domestic bees, approximately one colony is needed per acre of crimson clover. Where clover is to be used as a green manure crop and turned prior to seeding, there is no, need for pollination. Injurious Insects Several species of insects are destructive to crimson clover in the seedling stage, but effective control measures are known for them. The insects that normally cause the most injury in young clover are the fall armyworm, several cutworms, yellow-striped armyworm, and the Hawaiian beet webworm. Depending on clover size, 1 to 2 pounds of technical DDT or 2 to 4 pounds of toxaphene per acre will give satisfactory control of these pests. Either 10 to 20 pounds of 10 per cent DDT dust or equivalent amounts of DDT in sprays can be used. Do not graze lactating dairy animals on clover treated with DDT or toxaphene. Other animals may be returned to DDTor toxaphene-treated clover 7 days after treatment. Remove beef animals from treated clover 8 weeks before slaughter. On clover to be grazed by lactating dairy animals, 1 to 2 pounds technical methoxychlor may be used provided animals are kept off the clover for 7 days after treatment. Malathion at 1 to 2 pounds technical per acre may be used and cattle replaced 3 days after treatment; however, insect control is less effective than with DDT, toxaphene, or methoxychlor. At least two species of clover head weevils attack crimson clover heads, and may drastically reduce seed yields. The lesser clover leaf weevil and a closely related species are the most im- 26 ALABAMA AGRICULTURAL EXPERIMENT STATION 26 ALABAMA AGRICULURA XEIEN TTO TABLE 12. CRIMSON CLOVER SEED YIELDS FOLLOWING INSECTICIDAL TREATMENTS FOR CONTROL OF THE CLOVER HEAD WEEVIL, FIVE EXPERIMENTS' Per acre seed yields with different insecticidal treatment Dusts' 1958 Exp. 1 Exp. 2 Lb. Lb. 78 145 No treatment----134 317 8-----_. SeVin ------288 253 Cuthion-------------343 218 Heptachlor----___184 394 Endrin-______________. --------- ____ Malathion Treatment Parathion- Aldrin -----------Dieldrin DDT----- -- - -----Korlan----------------- 1960 Exp. 5 Lb. 127 182 157 219 182 ---222 187 Granules 3 1959 1960 Exp. 3 Exp. 4 Exp. 5 Lb. Lb. Lb. 132 288 346 550 436 Sprays 4 1960 Exp. 5 Lb. 130 222 470 716 -209 545 852 -200 -- 540 _-_ 646 376 240 12 _ 201 ----------- -------- 206 661 208 ---- Methyl Trithion Thiodan------Dimethoate__1____76 -226 --- 226 -- 215 Dibrom - -- - -- - 149 'Unpublished data contributed by Sidney B. Hays, formerly of the ZoologyEntomology Department, Auburn University Agricultural Experiment Station. Experiments conducted in Autauga and Talladega counties. 2 Dusts applied at full bloom stage, one application at 25 pounds per acre. 3 Granules applied in March, 2 pounds technical material per acre. applied at full bloom, 1/2 pound technical material per acre. 'Sprays portant of the weevils that attack clover heads. Research at this Station has shown that good control of these weevils may be obtained by treating clover fields in early spring before the clover blooms, using 1 pound of technical heptachior, endrin, or dieldrin in granular formulation, Tables 12 and 13. Twenty pounds of 5 per cent granules per acre is the correct amount. Lactating dairy cattle must be kept off clover fields treated with. these materials; however, all grazing animals must be kept off clover after blooming begins if a good seed crop is to be made. Treatment of clover when it is in 50 per cent bloom with either 20 pounds of 2 / per cent heptachlor or 5 per cent DDT, or 25 poumds of 2 per cent endrin or 2 per cent parathion dust per acre is also effective. Equivalent amounts as sprays may be used. Do not allow cattle to graze for the remainder of the season following application of any of these insecticides except parathion. Several species of mites attack crimson clover. They include the clover mite, strawberry mite, and the two-spotted mite. They can be controlled with dusts of 5 per cent malathion or 1 per cent parathion or equivalent amounts as sprays. CRIMSON CLOVER 27 CRIMSON CLOVER TABLE 13. CRIMSON CLOVER SEED PRODUCED WHEN TREATED WITH 1 HEPTACHLOR AT FOUR DATES DURING 1959-60, AUTAUGA COUNTY' 2 Date of treatment Seed yield per acre 1959 1960 March 22 (pre-bloom)----------------April 7 (10% bloom)--------------------------------April 18 (50% bloom)-----------------------April 25 (90 bloom)-------------------------Un tre a ted --------- ---------- ---------- ---------- ---------- ---------- --------- Lb. 715 561 854 507 28 8 Lb. 240 198 187 204 1 82 % pounds of technical material per acre. Unpublished data contributed by Sidney B. Hays, formerly of the ZoologyEntomology Department, Auburn University Agricultural Experiment Station. 2 'Two Caution The insecticides recommended for control of clover head weevil are highly toxic to honey bees. Honey bees are essential for clover seed production; therefore, these insecticides should be applied early in the morning or late in the evening when bees are not working on the blossoms. Care should also be taken to avoid dusting or spraying in or near bee yards. DISEASES Although crimson clover is attacked by several diseases in Alabama, no one disease consistently causes great damage. A brief description of these diseases follows. Major Diseases in Alabama Crown and Stem Rot, caused by a soil-borne fungus, S cierotinia trifoliorum, is widespread throughout the State, Figure 12. In addition to crimson clover, alfalfa, Ladino clover, and medium red clover are also susceptible to the disease. It is most destructive during the winter on seedlings, although plants of all ages are susceptible. It can develop and spread quickly and is recognized by circular, scalded patches of dead and in affected fields. Grazing tends to reduce the amount of damage from the disease. Knight (8) found more damage in thick stands than in thin ones and found that clipping the forage reduced the damage. Rotations using grass crops- resistant to the fungus also can be an effective way of checking the disease. -dying plants 28 ALABAMA AGRICULTURAL EXPERIMENT STATION Dead and dying crimsan clover plants show effects of crown and stem FIG. 12. rot, a disease that is widespread throughout Alabama. The bare spot shown is part of a circular area of dead plants, which is characteristic of crimson clover fields where the disease is present. The photograph was made March 1958 at the Plant Breeding Unit, Tallassee. Sootv Blotch mray- occur (hiring latt' wxinter and early spring. It is caused bx' a fungus, Cymadothca trifoii, wxhich produces dark-browni or black anu1lar blotcheits that afr' mofre prex alet']i onu the lower surface. The organism can cause partial defoliationI althouagh such leaf loss is uisually of minor conise'quene. No great loss will occur if affected areas are mowedc or grazed betfore sev erte leaf tdamage occurs. The regrow th will prohably hav e less disease. Minor Diseases in Alabamo Although considered of minor consequetncet tbrougho~ut the State, the follow ing tdescribedt diseases can cause considerable' damage to crimson clov er in localized areas: Southern Anthracnose is caused by a fungus organism, (.o1(etotrichium trifolii . Anthracnose occurs as small tdark spots on the stems, petioles, antd flower stalks. Girdling of these' plant tissues by the fungus can cause wilting and hrowning abovet the girdle. Frecjuently the organism attacks the upper part of the taproot andi crown, resulting in a taproot dlecay 01r crown rot that weak- CRIMSON CLOVER 29 ens or kills affected plants. The development of resistant varieties offers the most promise of control. Rust, caused by the fungus Uromyces trifolii fallens, may induce major damage on leaves and petioles. If pustules of brown rust are abundant and well developed, the upper leaf surface becomes reddish-brown to yellow, and the leaf then curls or withers and dies. The attacked petioles may result in a decreased supply of nutrients to the leaves. Mosaic is a virus disease that occurs commonly on crimson clover leaves. Its symptoms are leaf curling, crinkling, and mottling. Size of leaves may be reduced. Severely affected plants may be dwarfed or weakened and unable to withstand prolonged drought or severe cold temperatures. Root Knot, caused by the nematode Meloidogyne sp., is prevalent in most of the sandy soils in this State. Attack by this organism results in plants with yellow and stunted top growth and with knots, or galls, on the roots. Rotations, using crops resistant to nematode attack, will deplete nematode populations in infested soils. 30 ALABAMA AGRICULTURAL EXPERIMENT STATION LITERATURE CITED Auburn (1) ADAMS, FRED. Response of Crops to Lime in Alabama. Univ. (API) Agr. Expt. Sta. Bul. 301. 1958. (2) BAILEY, R. Y., WILLIAMSON, J. T., AND DUGGAR, J. F. Experiments with Legumes in Alabama. Auburn Univ. (API) Agr. Expt. Sta. Bul. 232, 1980. (3) BLAKE, GEORGE H., JR. The Influence of Honey Bees on Yield of Crimson Clover Seed. J. Econ. Ent. 51 (4) :523-527. 1958. (4) COPE, J. T., JR. Grow or Buy Nitrogen for Corn? Highlights of Agr. Res. Auburn Univ. (API) Agr. Expt. Sta. Vol. 2, No. 3. 1955. (5) DUGGAR, J. F. Soil Inoculation for Leguminous Plants. Auburn Univ. (API) Agr. Expt. Sta. Bul. 87. 1897. . Experiments with Crimson Clover and Hairy Vetch. (6) -_----------Auburn Univ. (API) Agr. Expt. Sta. Bul. 96. 1898. (7) .---------------------Crimson Clover. Auburn Univ. (API) Agr. Expt. Sta. Bul. 147. 1909. (8) KNIGHT, W. E. The Effect of Thickness of Stand on Distribution of Yield and Seed Production of Crimson Clover. Miss. State Univ. Agr. Expt. Sta. Bul. 583. 1959. HOLLOWELL, E. A. The Effect of Stand Density on (9) Physiological and Morphological Characteristics of Crimson Clover. Agron. Jour. 51:73-76. 1959. (10) LANGFORD, W. R. Crimson Clover - Still the Top Forage Producer. Highlights of Agr. Res. Auburn Univ. (API) Agr. Expt. Sta. Vol. 4, No. 4. 1957. (11) WEAR, JOHN I. Boron Requirements of Crops in Alabama. Auburn Univ. (API) Agr. Expt. Sta. Bul. 305. 1957. ---- -AND CRIMSON CLOVER 31 CRIMSON CLOVER 31 ACKNOWLEDGMENT This report covers data obtained by workers of the Agricultural Experiment Station of Auburn University over many years and draws on the experience of personnel on the Substations and Experiment Fields, and County Agents of the Extension Service of this University. Tests on the Substations were conducted by J. K. Boseck, C. A. Brogden, V. L. Brown, W. W. Cotney, S. E. Gissendanner, E. L. Mayton, and H. F. Yates. Work on the Experiment Fields was conducted by F. E. Bertram, F. T. Glaze, and J. W. Richardson and on the Plant Breeding Unit by J. W. Langford. Data on drying and storing crimson clover seed were obtained by H. S. Ward, Jr.; data on the control of the clover head weevil were furnished by S. B. Hays; the section entitled "Inoculation" was prepared by A. E. Hiltbold; the section entitled "Insects" was prepared by W. G. Eden; and the section entitled "Diseases" was prepared by J. A. Lyle. Data concerning forage yields of varieties were obtained as a part of regional tests conducted cooperatively with the Forage and Range Research Branch, A.R.S., U.S. Department of Agriculture, and several states in the southern region. L'=. .si3t is widely grown in Alabama, using know-how provided by research of Auburn University Agricultural Experiment Station. Studies dating back to 1896 have been done in all parts of the State (see map below) to learn best methods of production. In the early research, crimson was tried as a soil builder. Later emphasis was shifted to growing it as a forage crop. The cover photograph made April 21, 1960, shows Autauga reseeding crimson on the form of William E. Mathews, Ill, in Autauga County. Growing in Coastal Bermudagrass sod, the clover was planted in 1951 and has reseeded each year. The grass was established in 1954 as a perennial hay crop. It is clipped close in the fall to ensure a good stand of crimson. 7~, ~a