BULLETIN 396 NOVEMBER 1969 * YUCH I ARROWLEAF CLOVER Agricultural Experiment Station Auburn E. V. Smith, Director/ University ubrn Alabama ON THE COVER. Yuchi arrowleaf clover has a distinctive appearance that makes it easy to recognize at all stages of growth. The cover photograph, made in central Alabama during late June when seed heads were near maturity, shows the characteristic appearance near end of the growing season. SUMMARY Yuchi arrowleaf (Trifolium vesiculosurn) is a highly productive winter annual clover that is adapted to well drained soils in most of Alabama and areas of similar climate. Some features of this clover, which was released by Auburn University Agricultural Experiment Station, are: (1) 2 months longer productivity in the spring than crimson, (2) excellent drought tolerance, (3) high percentage of hard seed and good reseeding ability, (4) better seed germination at low temperature than crimson, (5) high forage quality throughout the productive season until maturity in June, and (6) excellent resistance to alfalfa weevil and clover head weevil. Based on results of Alabama experiments, these suggestions are offered for growing Yuchi arrowleaf clover: 1. Select well drained soil. Avoid poorly drained and highlime soils of the Black Belt. 2. Soil test to make sure fertilizer and lime needs are met. Yuchi is not a low fertility clover and will not produce well on very acid soil. 3. On prepared land, plant early to obtain maximum autumn growth. In northern Alabama, this means late August or early September. Farther south, mid to late September is fine. Plant 5 to 8 pounds of scarified and inoculated Yuchi seed with 1 bushel of rye per acre. Use special arrowleaf clover inoculum. Plant clover seed at a depth of 1/8 to 1/4 inch. 4. Plant only certified Yuchi arrowleaf to be sure of obtaining high quality seed of the right variety. 5. Plant on bahia or bermudagrass sods later, after they become dormant. Grass should be mowed or grazed closely in the fall before overseeding with clover. 6. To prevent seedling loss by striped field' crickets, apply1 pound active Diazanon granules per acre. Do not depend on natural reseeding of clover under continuous grazing. Overseed grass sod each fall. 7. Permit clover plants to make 6 inches of growth before grazing. 8. If a hay or seed crop is desired, stop grazing in early April. CONTENTS Page SUM M A RY -- - ------ -------- - - - ----- - - - - - - - - - - -- 3 - --- - ORIG IN- - -- - - - - - - -- - - - - - - - -- - - - - - - D ESCRIPTIO N -- - -- - - -- SEED GERM INATION --- - 5 -- - - -- - -- - -- - -- -- 6 --- - - ----- ---- --- ------ 7 FORAGE PRODUCTION ON PREPARED LAND-9 Clover A lone -----Clover-Grass FORAGE SOIL --- ---- -- - ---- --- -- ------ -- 9 Mixtures - - - - - -- - - 11--- PRODUCTON ON SUMMER GRASS SODS-12 -- --- --- -- --- ---- --13 REQUIREMENTS ------ Soil Fertility and pH -- -- ---Soil D rainage--------- - -- -- -- -- - ----------- -13 -15 MANAGEMENT FOR PASTURE AND HAY-16 FORAGE QUALITY AND ANIMAL PERFORMANCE -------------- 18 Forage Digestibility---------------------------------18 Steer G razing Results ------------------------------- 20 SEED PRODUCTION ------------------------------------- 20 25 27 Weed C ontrol ------ -- ---- -- -- ------ --- ------- --- -- 22 D essic an ts _- - -- - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - -2 3 B ees -- - - - -24-- - - - -- - - - -DISEASES AND LITERATURE INSECTS --------------------------------- CITED --------------------- FIRST PRINTING 4M, NOVEMBER 1969 YUCHI ARROWLEAF CLOVER C. S. HOVELAND, E. L. GARDEN, G. A. BUCHANAN, E. M. EVANS, W. B. ANTHONY, E. L. MAYTON, and H. E. BURGESS* UYCHI ARROWLEAF CLOVER (Trifolium vesiculosum Savi), a reseeding winter annual legume, is adapted to well drained soils in Alabama. It makes high yields of forage in late winter and spring, maturing about 2 months later than crimson clover. ORIGIN Released by the Auburn University Agricultural Experiment Station (5) and named for an Indian tribe that once inhabited eastcentral Alabama, Yuchi is a selection of arrowleaf clover introduced from Italy in 1956. The introduction, P.I. 233816, was first grown at the Southern Regional Plant Introduction Station, Griffin, Georgia. Plantings were made in Alabama by the Soil Conservation Service. It probably dates back to selections made in the 1930's by Prince Tuleo Ruffo of Calabria from T. vesiculosum plants growing in uncultivated places in the district of Segni (Rome), Italy (11). Favilli (3) in Italy described this species as being drought resistant, high yielding, hard seeded, and having considerable cold resistance. Two other arrowleaf clover varieties have been released in the United States. Amclo (2), released by the Georgia Agricultural Experiment Station and Soil Conservation Service, matures 2 to 4 weeks earlier in the spring than Yuchi. The Mississippi Agricultural Experiment Station and the Soil Conservation Service released Meechee (10), which is somewhat later maturing than Yuchi and is reported to be more cold hardy. ' Respectively, Professor, Research Associate, Assistant Professor, and Associate Professor, Agronomy and Soils; Professor of Animal Science; and Superintendent and Assistant Superintendent, Piedmont Substation. ALABAMA AGRICULTURAL EXPERIMENT STATION DESCRIPTION Yliehi arro~s eat cloy (r maflk(s its ( al grow01 1-r0111 a leal rosette, similar to crimlsoni clo\er, later productin~g 1)ranceIin'g stem;1 that culr\ c upw\\ard andi attainit l(Jt1 of 24 to 6() ines. Illc ae thick houllow~ stems are of tent purple, beeoifi filnrotis and( hardi neoar l11atlifit\ \\hite stipoiles, v\ hicho to a p)oint, are at the hasc~ ofl the p~etioles. Theo leax es are lark, each of, the three leaflets 1 eiu i 1 _ to :3 inc(hos lon g ai 1 to 111 inchles wideo. Each aiIIow-s hap e(1 Iion-hoir\ leaflet has 1 pniioiou cl cinand (10 dle\ ('lops a large, xx bte. \'"-shapced mark as it mjatuires, Fiittre 1. Coiisiderahle xariatiolo ill plat tyKpe occurs \ ithiui the \ arietx. Leaf petioles are 3 to 8 iiiches loi.. Lolig uartliw of tet (eecedlili __ inchdes in lenth~~ andi1 I iojles in tdiamieter, Fi(rc 2. F'ro)i 150( to lit) ii idea jlt florets mike upl the head, thet Corolla hciiigr \x lute initially an later tuiriing; pinik to puriple. This (,ix es each head at pinik-purpleo Thet floxverbeads are conical, FIG. 1. Pronounced veins and large V-shaped mark on each leaflet are identifying features of Yuchi arrowleof clover. YUCHI ARROWLEAF CLOVER 14, fP.a/ , FIG. Yuen. orrowleat clove r heads neor mnatwil in late June in central Alabama. ai swn in this photo made whilte strip~ed il)apearace. I'loxx rii~ini tiall\' o)tturI' Iioiu ini eutial Alabama, lt 1 )honlhiI' rn bxie d''lax ed b)\ grazinlg and~ or goodl so il iiioisti ire. [~al-l floret produces( two to three rotw4i ( i n~W 5(eeds, each ab~ou t tw ice the sire of wh ite clo\ (F seed. There are abouit 400,000)( seedl pe-r poundi~. ad( late Mla\ to luIN SEED GERMINATION Yutchi airo l( at cloy er germniates mlore raipily at 40) I temipeatr thain croison (loxer. Iji(ire 3. At alt(-rnating temiperaturo-s. such as one igtht expect at the soil suriface, low temper~~'ahure olurit tr the seed sxx l lilw peiriod redu ces gem liuiat ioni and1 x ilgor of cr1imison c-lox er 1bu~t has io effect on Y ic-hi arroxxleaf () 8 V Per cent germination 80 ALABAMA AGRICULTURAL EXPERIMENT ~~L~Yr STATION 60 40 F 20 Days FIG. 3. Germination of Yuchi arrowleaf clover seed at constant 40°F temperature is compared with that of ball and crimson clovers. The ability of Yuchi arrowleaf to germinate well at low temperature may be a valuable adaptive feature enabling it to produce new plants throughout the winter. Field observations in Alabama indicate that the number of new clover plants increases through December and January when moisture is good and temperatures are often low. Crimson clover, on the other hand, is less likely to germinate successfully during this period. A dry autumn followed by a cold winter may result in poor stands of crimson clover, while seeds of Yuchi arrowleaf frequently continue to germinate and grow throughout the winter. The seed coats of this clover are unusually hard and require more scarification than most other reseeding winter legumes. Hard seed content of combine harvested seed may exceed 70 per cent. Mechanical scarification of Yuchi arrowleaf by commercial scarifiers reduces the hard seed content to about 25 per cent. Thus, it is essential that scarified seed be planted to ensure a stand the first year. Non-scarified seed may lie in the soil several years before seed coats break down sufficiently for germination. Good stands of Yuchi have been obtained in fields where no natural reseeding had been permitted for 4 years. YUCHI ARROWLEAF CLOVER 9 FORAGE PRODUCTION ON PREPARED LAND Clover Alone Yuchi arrowleaf has been tested at 10 Alabama locations by Auburn University Agricultural Experiment Station. It has been compared with crimson, ball, and Amclo arrowleaf clovers. In these tests, the 5- X 20-foot plots were replicated four times and clipped every 4 to 6 weeks after the clovers were 6 inches tall. Total annual yields of Yuchi arrowleaf have generally equalled or exceeded those of crimson or ball clovers, Table 1. At Muscle Shoals and Alexandria (near Anniston) in northern Alabama and at Prattville in central Alabama, Yuchi has been considerably more productive than crimson clover. Late spring droughts severely reduced Yuchi yields during several years in southern Alabama. Yuchi made poor growth at the Black Belt Substation on Sumter clay. Winter forage production of Yuchi arrowleaf has generally been lower than that of crimson clover. One factor contributing to less winter growth of Yuchi has been slow nodulation by nitrogenfixing bacteria, particularly on fields where it is planted for the TABLE 1. TOTAL FORAGE YIELD OF CRIMSON, BALL, YUCHI, AND ARROWLEAF CLOVERS, TEN LOCATIONS AMCLO Location and soil Years tested Per acre yield of dry forage Yuchi Amclo arrowleafarrowleaf Lb. Lb. 5,420 4,150 5,290 3,560 Lb. 3,930 3,680 Lb. 3,702 3,740 Northern Alabama T.V.A. Forage Research Area, Muscle Shoals, Sango silt loam.... Alexandria Exp. Field, Decatur clay __ _ _ Central Alabama Tuskegee Exp. Field, Boswell fine sandy loam Plant Breeding Unit, Cahaba fine sandy loam Prattville Exp. Field, Lucedale fine sandy loam Lower Coastal Plain Sub., Amite sandy loam _1 Black Belt Substation, Sumter clay Southern Alabama Monroeville Exp. Field, Magnolia fine sandy loam-........ Brewton Exp. Field, Kalmia fine sandy loam Gulf Coast Substation, Marlboro fine sandy loam -. - 2 4 2 8 6 1 2,550 3,890 4,770 4,780 2,120 8,230 3,670 4,940 1,660 3,180 4,020 3,640 3,750 3,230 4,260 4,060 1,790 2,360 5 5 7 4,060 4,210 3,220 3,740 3,560 2,830 4,140 4,490 3,810 3,000 4,180 2,520 10 ALABAMA AGRICULTURAL EXPERIMENT STATION first timie. \\er p112Jlanits nodu101(s early, wxiniter g~rowxtht o1 (1(\ lop YliJi has exceedled that of cim son . Yllchi arr)xx laf c2ontinuzes to groNN for ablout 2 mionths longier than crimsoni and~ 1 miouthi af ter ball closer iiatiires. Sinc u mu of, 'nich i s growthf is m] ade in late sprin1]g. hot (drx wc ather in Nx Iax and~ Juni n ta redu ce yijelds. I low ex cr, (drou1ght toleran ce is eccellel t and recox (lx is rapidl after rains. Ini con1trast, b all cloy et is loss dIrouight toleranit and~ forage x ieldls hax e fluct~uated more froiih xear to x ear. idnh hats gen erally be1 m~ lore produocti\ e thani tlhe Am1c1) \ ariots in Alabama, Table 1. \\ imter produictioni has p)een eojial or superior to Anwlo, but Xtichi has a longer spi-iig pit (luI(ti\ ( period. l3loontiiig of Anido b~eg~iis 2 to f xx((ks earlier than 1ncioi Iiguc4 redluc(ing forage dligestib~ilitx in late spring orag haested Nlax 17 at P~rattx ille hiad (ligestil ole (lrx Iiatter x alncis of, S pcr cen t for Yuichi and (65 pcrV cen t for Amloil. 92 f4 4.4 FIG. 4. Amclo arrowleof deft) was already in bloom when photo was made 18 at Plant Breeding Unit, Tallassee, but Yuchi (right) was still vegetative. May YUCHI ARROWLEAF CLOVER 11 TABLE 2. FORAGE YIELD OF CRIMSON AND YUCHI ARROWLEAF CLOVER MIXTURES, FOUR LOCATIONS Per acre yield of dry forage Location Crimson and Yuchi arrowleaf Lb. 3-year test Yuchi arrowleaf Lb. 5,360 4,530 4,800 5.560 Crimson Lb. 8,310 4,160 4,660 4,850 Prattville Experiment Field Plant Breeding Unit 2-year test Monroeville Experiment Field________________. Brewton Experiment Field 4,310 4,880 5,340 5,930 Since crimson generally produces more early winter growth and Yuchi arrowleaf more late winter and spring forage, mixtures of the two clovers would appear desirable. However, in experiments at four locations where the clovers were seeded together and harvested every 4 to 6 weeks, total yields were generally improved only slightly over Yuchi arrowleaf alone, Table 2. At Prattville, yields of the mixture were considerably lower than Yuchi arrowleaf alone. Winter forage yields of the mixture at all locations were generally higher and late spring production considerably below that of Yuchi arrowleaf alone. Clover-Grass Mixtures On prepared land, Yuchi arrowleaf can be planted with rye or with rye and ryegrass for a high quality, long season pasture. Yuchi grown in combination with rye or ryegrass has been productive over a longer period than crimson clover in similar mixtures, Table 3. In the 2-year experiment at the Plant Breeding Unit, Tallassee, planting was in mid-September on prepared land, and plots were harvested every 4 to 6 weeks. All treatments received 80 pounds of nitrogen per acre. TABLE 3. FORAGE YIELD OF CLOVER-GRASS MIXTURES, BREEDING UNIT, TALLASSEE, 2-YEAR AVERAGE PLANT Per acre yield of oven dry forage Mixture NovemberJanuaryApril- December Lb. Rye-Yuchi arrowleaf clover-...... Rye-ryegrass-Yuchi arrowleaf..... Rye-ryegrass-crimson clover ...... Rye-crimson clover.... 1,670 1,440 1,600 1,790 March Lb. 3,070 3,120 3,230 3,310 May Lb. 2,840 2,510 1,970 750 Total Lb. 7,580 7,070 6,800 5,850 12 ALABAMA AGRICULTURAL EXPERIMENT STATION Adding ryegrass to rye and crimson clover nearly tripled April and May forage yields, Table 3. This was not the case with rye and Yuchi arrowleaf clover, where ryegrass did not improve spring yields. Rye and crimson produced slightly more early winter forage than rye and Yuchi arrowleaf. April and May production by the rye-Yuchi mixture was nearly four times that of the ryecrimson mixture. Quality of the maturing forage in the latter mixture was much lower than in the rye-Yuchi arrowleaf. Further information on quality differences between the two clovers is given in the section, "Forage Quality and Animal Performance." FORAGE PRODUCTION ON SUMMER GRASS SODS Overseeding of bahia and bermudagrass sods with winter annual clovers can extend the grazing season by 4 to 8 weeks and provide higher quality forage. Good natural reseeding by the clover is desirable. In northern Mississippi, Yuchi arrowleaf reseeded well on Coastal bermuda sod over a 3-year period (9). At this location, most of the Yuchi growth was after May 1 and drought reduced clover yields slightly below that of crimson. However, total annual grass-clover yields were similar for both clovers. Reseeding of Yuchi was excellent on Coastal bermuda the second year at the Upper Coastal Plain Substation, Winfield, Table 4. In this experiment the grass was cut to 2 inches in late fall. Natural reseeding of clover and vetch occurred where these species grew the previous spring. Early spring forage yield of crimson was slightly higher than for Yuchi arrowleaf, but late spring growth of the latter resulted in considerably more total production. Reseeding of clovers is generally more uncertain on bahiagrass sod than on bermudagrass. In the Georgia Piedmont, researchers reported stand failures of Amclo arrowleaf 50 per cent of the time TABLE 4. FORAGE YIELD OF LEGUMES FROM NATURAL RESEEDING ON COASTAL BERMUDAGRASS SOD, UPPER COASTAL PLAIN SUBSTATION, WINFIELD, 1966-67 Legume Yuchi arrowleaf clover Autauga crimson clover Per acre yield of dry forage April 4 April 27 May 16 Lb. 1,620 2,100 Lb. 690 80 Lb. 1,100 0 Total Lb. 3,410 2,180 Ball clover 840 380 770 770 480 410 2,090 1,560 Hairy vetch YUCHI ARROWLEAF CLOVER 13 YUCHI ARROW~LEAF CLOVER TABLE 5. EFFECT OF BAHIAGRASS STUBBLE HEIGHT ON YIELD OF YUGHI ARROWLEAF AND.CRIMSON CLOVERS, STAND AND FORAGE AUBURN, 1968-69 1 Height of bahiagrass stubble, inches Plants per square foot, December 27 Per acre yield of oven dry clover April 16 May 23 Total No. Yuchi arrowleaf 1---------------------------------------- Lb. 830 Lb. 2,310 1,950 2,310 0 0 0 Lb. 3,140 2,630 2,430 1,340 1,220 68 0 3--------------------------------------6-------------------------------------- 17 19 14 680 120 Crimson 1---------------------------------------3---- -30 26 1,340 1,220 6 ---------------------------------------- ------------------------- ---------- 26 680 on bahiagrass, regardless of sod scarification or fertilizer treatment (1). Stubble height of perennial warm season grasses left in the fall may affect clover forage production. In an experiment at Auburn, bahiagrass was cut to different stubble heights in early November prior to seeding clover, Table 5. Stubble height had little effect on the number of clover seedlings in late December. However, a 6-inch grass stubble drastically reduced early spring production on both Yuchi arrowleaf and crimson clovers. The 3-inch stubble reduced forage yield only slightly below that of the 1-inch stubble. Recovery growth in late April and May was excellent on Yuchi arrowleaf at all stubble heights, producing over twice as much forage as crimson clover. Little information is available on natural reseeding of Yuchi arrowleaf on grass sods under grazing. It has been observed that cows continue to consume stems and heads of Yuchi in June and July on Coastal bermuda sod. This suggests that the clover plants may not produce enough seed for dependable reseeding under continuous intensive grazing. The earlier spring grazing and' improved quality forage obtained should offer enough incentive to replant Yuchi arrowleaf on grass sods each fall, especially since the required seeding rate is low. SOIL REQUIREMENTS Soil Fertility and pH Yuchi arrowleaf is more sensitive than crimson" clover to low soil phosphorus, Figure 5. Response by this clover to phosphorus, potassium, and lime on a previously unfertilized Marlboro fine ALABAMA AGRICULTURAL EXPERIMENT STATION '3P' FIG. 5. Response of Yuchi arrowleaf (top photos) ond crimson clover (bottom) to phosphorus fertilization is shown by growth in plots at Gulf Coast Substation, Fairhope, on January 6. Plots of both clovers in left photos got 13 pounds of P per acre, whereas plots at right were fertilized with 52 pounds P per acre. 1\iiLL 6. \\Ii I4:iiA (411 lil' EI iiiixi COxxi BAL xii (:Ox lxN \113 eiil\xi: or1 \i IS xiiiOH noon Stoxir xaaii'. I' MMiiLi'L ' 1i lis ci .Aiix ini'. e S xxiix kii l\xiii x. (ilAixin, IOiAAi,' Phosphor iiius andii piitixxi lii pondsil P addedl per acre Fo .igc %itli (Aftssc Yuchi III i'~\laf as((peieeiitagi ofi lest treatmaunt Cr ixsti P'it. 100 75 :35 1 79 (50 Io] Pctl. Soil pH 6(.0 Pct. 100) 52 1:3 0 85 78 52 26 1-3 0 52 52 Soil pH 5.0 .52 100) 100 100 100) 25 0 100 55 6 0 90 41 I00 62 77 58 Soiil text al ties at 1beginnjin o f C piiomenL t: 1 1 ,ieie (\vcaik aecid extraetuille ) a11d o .5.1). 3 pon ds 1Pand 4)) pi mods K per YUCHI ARROWLEAF CLOVER 15 sandy loam at Gulf Coast Substation, Fairhope, Table 6, shows Yuchi arrowleaf and ball clovers both made poorer growth than crimson at low soil phosphorus levels. When no phosphorus was added to this soil, Yuchi and ball clover plants died in the seedling stage, whereas crimson plants survived. Most cultivated soils do not show such extreme phosphorus deficiency, but low phosphorus level could be a problem on some pastureland that has received little fertilizer over the years. Yuchi arrowleaf growth also was less than the other two when soil potassium was low. The clovers differed considerably in their growth at pH 5.0. Yuchi arrowleaf and ball are less tolerant of soil acidity than crimson clover. As previously noted, Yuchi is not adapted to lime soils of the Black Belt. On these soils having a pH of 7.5 or higher, Yuchi plants were chlorotic and made little growth, apparently because of iron deficiency. Rogers (12) reported iron deficiency chlorosis of crimson clover on such a soil. Soil Drainage Yuchi arrowleaf makes little growth on poorly drained soils (8). This is an important consideration since flooding and wet soils are common in many areas of the State during the winter and early spring months. Field observations and greenhouse experi- Flooded 3 days in 10 BALL *****..* . . . .. over 3-mo. period H IM w Flooded 6 days in 0 ::IT.... "":::::::::""""""" .... . ;;; over 3-mo. period YUCHI :ARROWLEAF 20 40 60 80 100 Forage yield-per cent of clover on well drained soil FIG. 6. Yuchi arrowleaf showed less flooding tolerance than white or ball clovers, but performed better than crimson clover under both flooding treatments. 16 ALABAMA AGRICULTURAL EXPERIMENT STATION ments indicate that Yuchi is less tolerant of poor drainage than ball or white clovers, Figure 6, but will make more growth than crimson clover under these conditions. MANAGEMENT FOR PASTURE AND HAY As with most forage species, management has a substantial effect on Yuchi forage yields (6). Frequent cutting (to simulate frequent close grazing) reduced yields in a 2-year experiment at the Plant Breeding Unit, Table 7. Forage yield was highest when Yuchi arrowleaf was cut every 6 weeks. Harvesting at 5- or 6-week intervals (hay stage) decreased the productive period as did cutting every 4 weeks. Extended early spring droughts both years reduced yields. As expected, total yields were reduced by clipping weekly. However, yields differed little among 2-, 3-, or 4-week cutting intervals. There was a sharp reduction in number of live shoots on clover plants cut every 4 weeks as compared with the 3-week cutting interval, Table 7. Shoot numbers were even less on clover cut every 5 or 6 weeks. In general, the number of new buds and TABLE 7. FORAGE YIELD OF YUCHI ARROWLEAF AS AFFECTED BY CUTTING FREQUENCY, PLANT BREEDING UNIT, TALLASSEE, 2-YEAR AVERAGE Time between cuttings Live shoots per Dry forage yield foot of row in May per acre No. Lb. -2 5,240 6 weeks (hay stage) 5 weeks (hay stage) 4 weeks 3 weeks 2 weeks 1 week -21 -22 --- 1 10 29 3,950 3,250 3,080 2,830 2,120 TABLE 8. EFFECT OF CUTTING DATE ON FORAGE YIELD OF YUCHI ARROWLEAF, PLANT BREEDING UNIT, TALLASSEE, 1968-69 Per acre yield of dry forage Treatment season Cut every 2 weeks until Cut every 2 weeks until Cut every 2 weeks until Cut April 15 Cut April 1 and May 1 Cut every 2 weeks until then cut May 1 April 1 April 15 May 1 April 1, 2.170 - Early May 1 Lb. May 21 Lb. 5,220 780 210 0 0 0 Total Lb. 7,430 3,920 3,510 4,610 4,140 4,710 - Lb. 2,210 3,190 3,300 4,610 3,020 1,120 2,540 YUCHI ARROWLEAF CLOVER 17 shoots declined as cutting interval was lengthened, but the reduction was much greater when cut at the hay stage. The sharp decline in live shoots in late spring as the cutting interval was lengthened suggests that there is an approximate date at which grazing should be terminated if hay or seed production is desired. Results of an experiment at the Plant Breeding Unit show that cutting (or grazing) should cease around April 1 in central Alabama for maximum hay yield, Table 8. Similar results were obtained in another trial at Prattville. Two reasons may account for the poor regrowth and death of clover plants when a large cutting of hay is removed in mid-April or early May. First, fewer buds remain active under the dense shade of the hay canopy than when frequently clipped, Figure 7. More frequent defoliation, as is the case under continuous grazing, permits more sunlight to penetrate the sward and maintain buds in an active state. Second, the lack of reserve food storage in the stubble after a large hay cutting means that little energy is availLive shoots per foot of clover row 501- 30 Cut every 2 weeks until April I a Cut every 2 weeks until April 15 20 Cut every 2 weeks until May I X Cut April I and May I 10- " I I 0 May Cut every 2 weeksuntil April 1, then May I Cut one time April 15 March April FIG. 7. How time of cutting affected live shoot production of Yuchi arrowleaf was determined in the test at the Plant Breeding Unit, Tallassee. ALABAMA AGRICULTURAL EXPERIMENT STATION r1. a. in tis January scene in central seeding stand of Yuchi arrowleaf clover. iaaama, Deer catric are grazing a e s s. ilt contrast, more I rrab le for dlex (loping nexx leaxe andtemSt (J11(1 tly cut or gra/el Yuc arrowxxleaf (lox cr has short prostrate thi stem s containing 1)oth act i\e buds and food1 storage areas. From a practical standlpoint, hoxw shiould Yucehi be ttuniaged for maximum prodnetix itx? Cotntinuous grazin g after plants are 6 in ches tall xxill permit a long productix e season. Yutc 1hi has con siderable tolerance to animal trampling. Cloxver stand~s andi growxth haxve been good cx en when gFred durin g the xx,(4t xx iiter mouths, F'igure S. If it appears that there wxill ie surpltms formge duintg thn peak groxxing period of April and MIay , confining grazimor animals to a part of the pasture ini carlx April perm its the uingrazed portion to be cut for hay in Max or seed combined ill J1une. Since heax y groxxth can be expected, the ose of a crimper or stein crasher xx ill speedultp field clr\ ing. FORAGE QUALITY AND ANIMAL PERFORMANCE Forage Digestibility Fotage duoality of Yutchi arrowxleaf from a mianagem Itnit expot: tuet t at the Plant Breeding Un it xxas ex alnated onl the basis of digestible drv matter (1)1 \I ). 1)1 )\I xxas determined bw placig nyxlon 1bags cotntainting( form~e sanmples in the ruimten of steers fite xwith fistulas ( openings inl the rtmuen). The bags xxere reit ox od after 24 hours andl ility calculated on the 1basis of uni-l gestedl matter renaitingi in the bag. dIigestib YUCHI ARROWLEAF CLOVER 19 Digestible dry matter, per cent 90 80 Yuchi arrowleaf 3-week cutting 70 60 6 Yuchi orrowleaf 6-week cutting 50 40 0 Autauga crimson 3-week cutting February March April May June FIG. 9. Cutting frequency affected digestibility of Yuchi and crimson clovers. DDM of Yuchi arrowleaf remained at a high level (70-85 per cent) throughout winter and spring regardless of cutting frequency, Figure 9. Forage from the other cuttings made at 1-, 2-, 4-, and 5-week intervals had digestibility similar to that of the 3and 6-week treatments. Results were similar in both years of the experiment (6). For Coastal bermuda in the same trial, DDM was only 43 per cent. Generally, forages with about 65 per cent DDM or more are considered to have high quality. Thus, results of this experiment show that Yuchi arrowleaf cut at the hay stage has high quality. Quality also remained high during the blooming period in late May. In another experiment, hay cut May 21 and yielding over 21/2 tons per acre had DDM of 70 per cent, Table 8. In contrast, digestibility of crimson clover cut every 4 weeks was high in winter but declined rapidly in late March and April. Autauga crimson clover normally reaches full bloom by early April in central Alabama. In forage cut at the early bloom stage, DDM of leaves was similar for arrowleaf (84 per cent) and crimson (78 per cent). However, DDM of stems was 68 per cent for Yuchi but only 50 per cent for crimson. The high digestibility of stems probably accounts for the apparent high quality of Yuchi arrowleaf in late spring when it becomes more stemmy. These results agree with findings of Georgia experiments (13) that the amount of less digestible cell walls of arrowleaf clover remained relatively low until bloom stage, even though the percentage of stems in the forage was high. 20 ALABAMA AGRICULTURAL EXPERIMENT STATION Steer Grazing Results Rye, ryegrass, crimson clover, and Yuchi arrowleaf clover were planted on prepared land in September of 1967 and 1968 at the Piedmont Substation, Camp Hill. This 10-acre hilly red clay area had been fallowed during the summer months. Phosphorus and potassium were applied according to soil tests, with 80 pounds of nitrogen per acre added in fall and winter. Ten yearling beef steers grazed the pastures continuously from stocking in December until June each year. Steers were given a 24 mg. stilbestrol ear implant at the beginning of the experiment. No supplemental feed was used. Ten heifers were added to the grazing area from April 4 to May 16 in 1969 to utilize surplus forage. Excellent results were obtained both years, although there were greater gains over a longer period in 1968-69, Table 9. This is probably because of the better stands of Yuchi arrowleaf the second season. Rye furnished most of the early season forage and Yuchi arrowleaf produced most of the grazing from early April to June. Crimson clover made only a minor contribution, especially the second season. Ryegrass furnished grazing in late February and March when rye was booting. The average daily gains of 1.96 pounds in 1967-68 and 2.39 pounds in 1968-69 are highly satisfactory. Although per acre gains were good, it is likely that carrying capacity would be higher on less droughty soils. Steers were slaughtered directly off the pasture and graded high Good. SEED PRODUCTION Yuchi arrowleaf begins blooming in late May or early June and matures seed in late June or July. Seed are borne in clustered pods produced at tips of stems that remain erect if plants have not TABLE 9. PERFORMANCE OF STEERS ON RYE-RYEGRASS-YUCHI PASTURE, PIEDMONT SUBSTATION, CAMP HILL ARROWLEAF I Performance measure Dates grazing began and ended Average initial live weight, lb.-........... Average final live weight, lb.--............ Total gain per acre, lb. - . .. ... -341 Average daily gain per steer, lb. -------------.. . . . Resultant Winter 1967-68 Winter 1968-69 Dec. 13-June 3 590 931 1.96 Dec. 2-June 3 574 1,012 483 2.39 'Stands of Yuchi arrowleaf were thin the first year but excellent the second. Some crimson clover was present in the pastures, especially the first year. YUCHI ARROWLEAF CLOVER 21 FIG. 10. This Yuehi seed field in a pecan orchard, photographed June 23, shows promise of a good seed crop after being grazed until early April. mnade too muilch \ egetatx e grow th. Thie \ at 1 t is it foodl seed produtcer and seedl xieldLs of 1O() to 5300 pollllds per acre hlaxe lbeen rep)orted (1y) farmers. Sexveral p)ractices are necessary for satisfactory seed y ields5 of Yuchi arrow leaf love(r: (1) Potcu tial seed fields should be ,razed (hiringr winter until carly April. Failure to graze -,ill often result in extrely ei heax x growyth that miats dow II. rots, and produ~ces oly a small lnmber of seed heads. Regrow dl after grahllgr in a seed field undI~er pecans~ is show n in Fi gure 10. Thlin standt~s of clox er or late' planited clover urax (gixe little or no( gra/inl b lut often are tihe muost producetiv e seed fields. (2) Fields need to be checked careflly for dodder (C(uiscuitu sp. ) , andl anyx present should be remov ed. D~odder seedl are extremely (difficulit to separate from Yuclhi arrow leaf clover seed since bothl are of sinmilar size and1 has roullgih seedl coats. :31) Bees are esse(n tial for pollination. If nlot enloulgh nativ e bees are present, one colony per acre should be placed ini thec seed field. 4f) Seed harvsSt shlould be started in late June xx het weather is usually sunny, dry, and hot. Jlyx is genterallix a et motnth in Alabama, makinlg seedI harvest difficult an d somnetitmeUs impossib~le. Yuchi continues to flower and the stems may remtaitn green muchl ( ALABAMA AGRICULTURAL EXPERIMENT STATION ~. FIG. 11. Being combined in mid-July, Yuchi still has some immoture seed heads. of J nix\, cIt though there is at c% ~l Iteax ) Crop of' mature seed head;. 1i(rr 11. iDrx ite of' the p~lant mnaterial Cal 1he (lotne Im\ euttilir andi swv athit g, bitt so11 e seedi losses ttax ocecur \v iti this melthod. Dessieaitts are more (flectix e andt p~ermit dlireet eomn titiilg of th dryx plaits 2 to 5 day s after appliceation. ( See seetioni 01n lesicantts. Weed Control Wcedtls plesenit a mtajor prolemti illthe ecultutr( of Yn ii arr ow leaf cl)\ cr. Broadleaf \\ itter wee(d(1 ate itsutallthe mtost trotublesome. Atual xx inter gasses of tent occiur but se1lom offer attx seiouts comltpetitiont. Cir IF\ lock (Rlw cir0 isp/i.s ), oiitlea, ce ii It primi rose (Ocnothc('(1 laninit ata) pt'pperwxeed (Lcp idii, Ot r1 ) , atnd( Campho red(( 11 cttroleci s .s iltla is) Jcomptri~1se atgro(ill oft the tmost imtportatnt ottes. 1IJeltiit ( Laotillm amtpje vicatlc ), caroling "gealtittlt ((A'rc tmnI/ill o i illr ), atnd little lharle\ ( Itordtiii /)tisillili Nutt) atc also of tetn foiund int Vtli atros lea. W\eeds are particutlarl y botberSOl I e dUr-ingI cloxer establish n et t. gilt11icut YUCHI ARROWLEAF CLOVER 23 YUCHI ARROWLEAF CLOVER TABLE 10. 2 WEED CONTROL AND FORAGE YIELD OF YUCHI ARROWLEAF CLOVER AS AFFECTED BY PREEMERGENGE HERBICIDE TBEATMENT, AUBURN AND PRATTVILLE, 1969 Herbicide, pounds per acre active vWeed control," Prttile Prattville Dry forage per acre Auburn Prattville DCPA, 4.0-----------------------90 DCPA, 8.0 ---------------------------------------90 DCPA, 12.0----------------------Chiorpropham, 2.0---------------------------55 70 Chiorpropham, 4.0----------------------95 Chiorpropham , 8.0---------------------------80 Pct. 65 Lb. 3,300 2,880 Lb. 3,380 3,240 2,580 950 220 3,720 3,890 3,150 4,150 ------------Benefin, 0.5 ------------------------80 540 Benefin, 1.0 ------------------------------------- 3,890 0 2,670 80 -Benefin, 2.0--------------Check ---------------------------1 0 1,620 2,780 3,090 - 0 3,720 No weeds at Auburn because of non-uniform weed populations. Weed seeds will often germinate ahead of the clover, when plantings are made during relatively dry periods. Especially when given the initial competitive advantage, weeds cause severe reduction in yield of forage and seed. DCPA (Dimethyl tetrachloroterephthalate), benefin (N-butylN-ethylcc, ac, cc ,-trifluoro-2,6-dinitro-p-toluidine), and chiorpro- pham (isopropyl m-chlorocarbanilate) have shown the most promise for preemergence weed control in Yuchi arrowleaf, Table 10. DCPA and benefin are primarily grass herbicides but give some control of small seeded broadleaf weeds. Chlorpropham is effective against annual grasses and many broadleaf weeds at 4 pounds per acre. Usually cool weather during weed control period favors results with this herbicide. None of the herbicides (except the 2 pounds per acre of benefin) mentioned in Table 10 caused any injury to Yuchi arrowleaf at Prattville. At Auburn, chlorpropham and benefin caused substantial injury. The major factors contributing to the greater injury at Auburn were lighter textured soil and a severe drought during the 12 weeks after herbicide application. When moisture did become available, temperatures were unfavorable for good growth. Consequently, the clover made no appreciable growth until mid-spring. Dessicants Dessicants may aid in drying plant material sufficiently for rapid seed harvesting at an earlier date, thus increasing seed saved. At the Prattville Experiment Field over a 2-year period, 24 ALABAMA AGRICULTURAL EXPERIMENT STATION 24 ALABAMA GRICULTURA XEIEN TTO TABLE 11. EFFECT OF DESSICANTS ON DRY MATTER CONTENT OF YIJHI ARROWLEAF CLOVER, PRATTVILLE EXPERIMENT 1968 AND 1969 FIELD, Dry matter content of plants 1968 1969 2 days 5 days 2 days 5 days Pct. Pct. Pct. Pct. Paraquat, 0.5 ----------------------------------86 90 69 68 Paraquat, 0.75 .--------------------------------84 88 64 66 Endothall, 0.75 --------------------------------- 60 68 88 59 Sodium cacodylate, 3.0--------------------. 77 90 58 62 Clytac (diesel), 1.5 -------------------------72 90 64 74 DNBP (diesel), 1.5 --------------------------88 96 73 76 Check ------------------------------ ---------76 79 54 54 Cut and windrowed-----------------96 92 A t application-------------------------------66 56 -- Dessicants, pounds per acre active' 'Applied June 26 in both years. dessicants were applied June 26 and seed harvested 2 and 5 days after application, Table 11. Dry matter content of the clover was determined at time of application and at each harvest date. Severe drought in 1968 reduced moisture content of the plants to a lower level at application time and caused faster drying than in 1969. Seed yields averaged 240 pounds per acre in 1968 and 440 pounds in 1969. Seed germination was not affected by any of the dessicants in these experiments. Dinoseb (2-sec-butyl-4,6-dinitrophenol) in diesel oil was one of the most effective dessicants in both years. Paraquat (1,1'-dimethyl-4,4'-bipyridinium) and Glytac [ethyleneglycol bis (trichloroacetate) ] in diesel oil also caused fairly rapid drying. Sodium cacodylate (arsenic acid) and endothall (7-oxabicyclo However, none of the dessicants caused plants to dry as rapidly as cutting and windrowing.* The latter treatment likely may result in a greater seed loss than when the clover is combined directly. Bees [2.2.1]1 heptane-2,3-dicarboxylic acid) resulted in slower drying. Yuchi arrowleaf clover requires bees for seed production. In two 1969 tests in central Alabama, a honey bee colony was placed in the center of clover fields. Seed per head were counted in 100 seed heads collected at various locations in the fields, including those from plants in a screen cage that excluded bees. Numbers of seed per head from the caged areas were 0 and 3, whereas heads outside the cage had 96 seed per head at one location. and 49 seed at another. No difference was noted in distance from the YUCHI ARROWLEAF CLOVER 25 bee colony. The large number of native bumble bees present in both fields was probably sufficient to pollinate the clover. DISEASES AND INSECTS No serious disease problems have been encountered with Yuchi arrowleaf clover. It is susceptible to crown and stem rot (Sclerotinia trifoliorum) like other clovers, and stand losses may occur during warm, wet, winter periods. The problem is more severe where a heavy accumulation of forage occurs. Grazing the clover to remove surplus growth and permit light to penetrate the sward will reduce disease losses. Yuchi arrowleaf is remarkably resistant to insects that attack many other legumes. Clover head weevil (Hypera meles) causes severe seed losses in crimson clover but has little effect on Yuchi. Weevil counts made weekly during late spring at the Plant Breeding Unit showed populations were much lower on Yuchi than on ball or crimson clovers. Alfalfa weevil (Hypera postica) numbers have been extremely low on Yuchi arrowleaf clover adjacent to mike clover that was severely damaged by large numbers of weevils (4). Little or no alfalfa weevil damage has been noted on leaves of Yuchi as compared to severe damage on alfalfa. YUCHI ARROWLEAF CLOVER 27 YUCHI RROLEAF CLOVER 2 LITERATURE CITED (1) (2) (3) E. R. AND J. D. POWELL. 1969. Forage Production of Amclo and Crimson .Clover on Pensacola Bahiagrass Sods. J. Range Mgt. 22:36-39. ______________________, J. D. POWELL, AND R. A. MCCREERY. 1968. Amclo Arrowleaf Clover. Crop. Sci. 5:284. FAVILLI, R. 1958. Alcune richerche ed osservazioni sopra 11 "Ruffo di Calabria" (Trifolium vesiculosum Savi). (Research and Observations on Ruffo di Calabria clover.) Pisa Univ., Esperienze e Richerche 6:33-51. HOVELAND, C. S. AND M. H. BASS. 1963. Susceptibility of Mike Clover (Trifolium michelianum Savi) to Alfalfa Weevil. Crop Sci. 8:452-458. _------------------ 1967. Registration of Yuchi Arrowleaf Clover. Crop Sci. 7:80. 1970.'------------------------ AND J. P. CUNE. L. CARDEN, W. B. ANTHONY, NINGHAM. 1970. Management Effects on Forage Production and Digestibility of Yuchi Arrowleaf Clover (Trifolium vesiculosum Savi). Agron. J. 62: (in press). AND D. M. ___________________________ELKINS. 1965. Germination Response of Arrowleaf, Ball, and Crimson Clover Varieties to Temperature. Crop Sci. 5:244-246. BEATY, trifoglio (4) (5) (6) ---------. (7) Annual Clovers. Agron. J. 57:8-4. (9) KNIGHT, W. E. 1966. Comparative Reseeding and Forage Production of Crimson and Arrowleaf Clovers Grown in a Coastal Bermudagrass Sod. Proc. Assoc. South. Agr. Workers 68:84. (10) _____________ V. E. ALDRICH. AND M. BYRD. 1969. Registration of Meechee Arrowleaf Clover. Crop Sci. 9:398. (11) PETRI, L. 1939. Survey of Phytopathological Records in 1988. Boll. Staz. Pat. veg. Roma. AND H. L. WEBSTER. (8)----------------------------1965. Flooding Tolerance of 19:115-188. (Herbage Abstr. (12) Clover on a Cal1947. Iron Deficiency of careous Soil and Method of Diagnosis. J. Amer. Soc. Agron. 89:688639. ROGERS, H. T. Crimson 10:1045. 1940.) (13) STANLEY, R. L., E. R. BEATY, AND D. N. PALMER. 1968. Effect of Age at Harvest on Yield and Cell Wall Content of Amclo Clover. Aaron. 1. 60:843-844. AGRICULTURAL EXPERIMENT STATION SYSTEM OF ALABAMA'S LAND-GRANT UNIVERSITY With at a grictulturtal reseatrcht Itnit in everx' iiajor soil area, Auburn tlic Unix ersity serves needs of field crop, li estock, foresttrx,. and horticultiiral producers in each regiot iti Alahaiiia. Exverx citizen of the State has a stake in I U - .1 1 Q this reseali program, since anx ad(vanta e f rom neWt and more xxa\ s of 1o : nL >®. ® ec oilnical produttcing and handling Lunt produ 'lcts directly publllic. Research Unit Identification 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. Tennessee Valley Substation, Belle Mina Sand Mountain Substation, Crossville. North Alabama Horticulture Substation, Cuilman. Upper Coastal Plain Substation, Winfield. Forestry Unit, Fayette County. Thorsby Foundation Seed Stocks Farm, Thorsby. Chilton Area Horticulture Substation, Clanton. Forestry Unit, Coosa County. Piedmont Substation, Camp Hill. Plant Breeding Unit, Tallassee. Forestry Unit, Autauga County. Prattville Experiment Field, Prattville. Black Belt Substation, Marion Junction. Tuskegee Experiment Field, Tuskegee. Lower Coastal Plain Substation, Camden. Forestry Unit, Barbour County. Monroeville Experiment Field, Monroeville. Wiregrass Substation, Headland. Brewton Experiment Field, Brewton. Ornamental Horticulture Field Station, Spring Hill. Gulf Coast Substation, Fairhope.