ESTABLISHING SERICEA LESPEDEZA at LOW SEEDING RATE with a HERBICIDE CIRCULAR 174 FEBRUARY 1970 AGRICULTURAL EXPERIMENT STATION A U BUR N E. V. Smith, Director U N IV ERS IT Y Auburn, Alabama CONTENTS Page EXPERIMENTAL PROCEDURE---------------- R E SUL T S - - - - - - - - - - - - - - - -- - -- - -- - -- - -- - - - 4 Year of Establishment---- ---- --- - --- - - 4 Second Year Stand --------------------------- 7 SUMMARY AND CONCLUSIONS----------------------------8 ACKNOW LEDGM ENT------------------------------------- 9 LITERATURE CITED ------------------------------------- 10 A P PE N DIX - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - 1 1 FIRST PRINTING 3M, FEBRUARY 1970 Establishing Sericea Lespedeza at Low Seeding Rate with a Herbicide C. S. HOVELAND, G. A. BUCHANAN, and E. D. DONNELLY Department of Agronomy and Soils ERALA, an improved sericea (Lespedeza cuneata) variety with good forage quality (2,3) has stimulated new interest in this crop. Farmers at times experience difficulties in establishing sericea. Even with good stands, generally no forage is obtained the year of establishment. Unfortunately, sericea seedlings are weak and compete poorly with spring and summer weeds. Heavy seeding rates of 30 or more pounds per acre have been recommended to allow sericea to be more competitive with weeds. Additional cost of heavy seeding rates limits planting of new improved sericea varieties. Several herbicides give acceptable control of grasses and broadleaf weeds in sericea (1). EPTC (Eptam) gives good control but may cause injury to sericea, particularly on sandy loam soil. Vernolate (Vernam) is the most promising herbicide as it gives good weed control and has caused no injury to sericea with rates as high as 9 pounds per acre. The objective in this study was to determine if satisfactory sericea stands and first year forage yields could be obtained using a low seeding rate with vernolate. S EXPERIMENTAL PROCEDURES Experimental plots were planted in March, 1968 and 1969 on Cahaba fine sandy loam at the Plant Breeding Unit, Tallassee (central Alabama). Another test was planted in April, 1969 on Decatur clay at the Tennessee Valley Substation, Belle Mina (northern Alabama). Vernolate was incorporated preplant with a disk harrow adjusted to run 4-6 inches deep. Vernolate was applied at 0, 2, 3, and 6 pounds per acre. In 1968 the 2 pounds per acre rate was not used. Application was made with a knapsack sprayer using 15-20 gallons of water per acre and a spraying pressure of 30 p.s.i. Serala sericea was seeded broadcast at rates of 10, 20, and 30 pounds per acre and cultipacked. Better stands result from broadcast seeding than drill seeding (4). Plots 10 X 20 feet were replicated four times. Counts of grass and broadleaf weeds and sericea seedlings were made during the spring. Forage was harvested once during the year of establishment on all experiments and twice the second year at the Plant Breeding Unit. One-half of each plot was not harvested the year of establishment to determine the effect of cutting on yield the next season. Samples were collected from each plot at harvest and hand separations made of sericea and weeds. RESULTS Year of Establishment Excellent weed control was obtained with 3 pounds of vernolate per acre at the Plant Breeding Unit in 1968. Stand counts showed virtually no grass or broadleaf weeds on vernolate treated plots, Table 1. Weeds, which were numerous on untreated plots, were primarily pigweed, crabgrass, and goosegrass. Sericea stands were not affected by vernolate. Herbicide application doubled or tripled sericea forage yields and resulted in sericea stands free of grass or broadleaf weeds. TABLE 1. EFFECT OF HERBICIDE AND SEEDING RATE ON STANDS AND YIELDS OF SERICEA IN ESTABLISHMENT YEAR AT PLANT BREEDING UNIT, 1968 Verno- Sericea late seeding rate rate rate rate Lb./ b Dry forage yield, Aug. 8 Stand, May 7 Weeds Weeds eSericeaSericea Grass Broadleaf Grass Broadleaf DI .v "1- ,c / , DI A,,Ln ,aiIi 6sq. ft. rti Lb./A. 6sq. ft. ra L b./A. 6sq. ft.A. b./A. 670 1,180 650 0 0 0 0 0 0 950 620 1,390 2,430 2,920 2,950 2,190 2,300 2,890 / 0 3 6 10 20 30 10 20 30 10 20 30 16 28 5 0 0 0 0 0 0 8 5 6 1 0 0 0 1 1 34 54 47 28 44 58 32 44 55 1,690 2,040 900 0 0 0 0 0 0 [4] Sericea seeding rates had only a small effect on weed stands or on yield of weeds and sericea. Increasing the seeding rate from 10 to 20 pounds per acre increased sericea stands but had little effect on yield. Another experiment, planted in 1969 adjacent to the 1968 test at the Plant Breeding Unit, had an additional treatment with a rate of 2 pounds of vernolate per acre. Results in this test were similar early in the season to those in 1968, Table 2. There was a sharp reduction in stands of grass and broadleaf weeds at all herbicide rates with no harmful effect on sericea. Much higher rainfall during May through July (17.6 inches in 1969 versus 8.4 inches in 1968) encouraged grass growth. Considerable fall panicum was present and this weedy grass was not adequately controlled by vernolate. Nevertheless, vernolate at 3 pounds per acre resulted in sericea yields about the same as 1968. Untreated seedings yielded virtually no sericea forage in 1969. Two pounds of vernolate per acre decreased weed stands in May but did not give satisfactory sericea yields because of weed growth later in the season. Heavy grass growth during the wet summer competed seriously with sericea. With no herbicide, grass yields of 3 tons per acre were obtained compared with about 11/2 tons per acre with 3 pounds of vernolate per acre. There was no advantage in increasing vernolate rates from 3 to 6 pounds per acre. Seeding rates, as in the previous year, had no effect on grass or broadleaf weed stands, Table 2. Increasing the seeding rate TABLE 2. OF EFFECT OF HERBICIDE AND SEEDING RATE ON STANDS IN ESTABLISHMENT YEAR ABREEDING AT PLANT AND SERICEA UNIT, YIELDS 1969 Sericea Vernoseeding late rate raGerate rae Stand, May 21 Weeds Sericea rass Broadleaf Plants/ 6 sq. ft. 7 6 6 1 1 3 1 0 2 2 2 1 Plants 6 sq. ft. 27 42 75 52 54 87 45 84 62 51 61 59 Dry forage yield, July 24 Weeds Sericea Grass Broadleaf Lb/A. 5,340 7,510 6,840 4,610 4,840 5,690 2,420 3,750 2,840 720 2,810 2,060 Lb./A. 20 0 410 170 100 60 0 100 20 60 490 290 Lb./A. 300 60 20 880 550 1,010 3,920 2,070 2,550 4,860 3,000 2,710 Lb./A. Lb./A.Plants / 6 sq. ft. 0 0 0 2 2 2 3 3 3 6 6 6 10 20 30 10 20 30 10 20 30 10 20 30 38 38 33 12 11 10 16 7 18 12 14 12 [5] from 20 to 30 pounds per acre increased sericea stands on nonvernolate treated plots. However, differences in sericea stands in May because of increased seeding rate had no effect on the yield of forage harvested in late July. Results at the Tennessee Valley Substation were similar to the 1968 test at the Plant Breeding Unit, Table 3. May through July rainfall totaled only 11 inches with most of this (6.4 inches) falling in May. Weed species at this location were mainly crabgrass, goosegrass, prickly sida, smallflower morningglory, tall morningglory, and red root pigweed. Stands of grass and most broadleaf weeds were sharply reduced by all rates of vernolate. Slightly higher broadleaf weed counts are attributed primarily to prickly sida and tall morningglory, species not controlled by vernolate. Sericea stands were unaffected by the herbicide. Although production was severely reduced by drought, sericea treated at all vernolate, rates yielded 3 to 4 times more than untreated plots. Seeding rates on this clay soil had no effect on grass stands but 30 pounds per acre seed reduced broadleaf weed stands and broadleaf weed yields, Table 3. Sericea stands increased with seeding rate but increased stands had no effect on forage yield. As shown in the photo, the sericea stand appeared sparse from 10 pounds seed and 3 pounds vernolate per acre but good forage growth had been made one month later. TABLE 3. EFFECT YIELDS OF OF HERBICIDE AT AND SERICEA SEEDING VALLEY RATE ON STANDS 1969 AND SERICEA TENNESSEE SUBSTATION, Verno- Sericea Stand, June 12 , Dry forage yield, Aug. 25 late seeding rate rate e rae Lb./A. Lb./ Lb./A. Lb./A. 0 0 0 2 2 2 3 3 3 6 6 6 10 20 30 10 20 80 10 20 30 10 20 30 Weeds Grass Broadleaf Plants/ 6 sq. ft. 24 29 10 4 7 4 1 2 4 2 2 1 Plants/ 6 sq. Sericea Plants/ 6 sq. ft. 54 92 174 52 124 118 69 127 151 48 131 154 Grass Weeds Broadleaf Lb./A. 900 870 670 1,180 450 640 790 470 460 400 500 210 Sericea Seriea Lb./A. 140 340 540 1,030 1,260 1,080 1,590 1,630 1,310 1,160 1,390 1,700 ft. Lb./A. 1,400 870 1,160 120 580 490 250 180 220 230 200 100 41 39 6 7 3 6 2 4 1 0 2 2 [6] ', - iv r S e its Seralo sericea seeded at 10 pounds per acre, Tennessee Valley Substation, left above, no vernolate and below, 3 pounds vernolate per acre, June 23; right above, no vernolate and below, 3 pounds vernolate per acre, July 24. Second Year Stand o11( Scricea stands at thte PlIant I-redinti Unit rx ()0 ('r' the seey ear, regatrdlless of 5(('(lill or hbi id~e rates the prex 10115 Seic)oar jatiton ined968, eeicrae 4l. apll 1 Tahle lear] Iota] h y ield(s the second~ eod\crhhricide ear mi re about .50 pet et thligher on sericea seeded at 10 pout11ds per acre' and( recei xing 3 poun1(15 -enolate per ace as comp1 1 ared xxitht no(herbicnide at the 1(10ound seedintg r ate. \'ertml ate-treatedl plots y ieldled more( fota("e than non-treated plots at both the xxhere and Juniy 24 hai (st dlates. althotugh stan ds wxere foodl v-ere nolate a o been appliedl the prex jots tyxear, sericea plan ts wxer~e small atnd less able to comp)ete xxiti xxeed(s. aecou nting~ for heaxAx xeedl gnth at 1)0th harv ests. TABLE 4. EFFECT OF HERBICIDE, SEEDING RATE, AND PREVIOUS CUTTING WEED-FREE FORAGE YIELD OF SECOND YEAR SERICEA AT PLANT BREEDING UNIT, 1969 ON rate Sericea seeding rate Lb./A. 10 20 30 10 20 30 10 20 30 Dry forage yield in 1969 Harvested in 1968 Not harvested in 1968 May 22 July 24 Total May 22 July 24 Total Lb./A. 1,410 1,870 1,880 2,910 3,280 2,480 3,210 3,400 3,570 Lb./A. 3,140 3,490 4,010 3,960 4,220 4,180 4,470 4,470 4,790 Lb./A. 4,550 5,360 5,880 6,870 7,600 6,660 7,680 7,870 8,360 Lb./A. 1,860 2,040 3,320 3,140 4,210 3,820 4,490 3,130 4,340 Lb./A. 3,990 3,670 4,530 4,070 4,820 4,400 4,820 4,530 4,470 Lb./A. 5,850 5,710 7,850 7,210 9,030 8,220 9,310 7,660 8,810 Lb./A. 0 0 0 3 3 3 6 6 6 Sericea seeding rates had little effect on forage yields the second year. This indicates that 10 pounds per acre was a sufficiently high seeding rate and that planting additional seed did not improve competition with weeds. Cutting sericea in the year of establishment caused an average 10 per cent reduction in forage yield the following year, Table 4. The yield reduction was greatest at the first harvest. This small yield reduction was more than compensated by forage harvested the establishment year. Sericea seeded at 10 pounds per acre and :treated with 3 pounds vernolate per acre yielded a 2-year total of 9,300 pounds per acre when cut the first year and 7,220 pounds per acre when not cut the first year. SUMMARY AND CONCLUSIONS Serala sericea was planted in field experiments to evaluate seeding rates and vernolate herbicide on establishment. Grasses and most broadleaf weed stands were sharply reduced and sericea unaffected by vernolate. Sericea seeding rate had little influence on establishment, weed competition, and forage production. Reducing the sericea seeding rate from the presently recommended 30 pounds seed per acre to 10 pounds per acre and applying 3 pounds vernolate preplant was the most economical and productive method of establishment. Sericea yields the year of establishment were increased 2 to 10 times when vernolate was applied. The beneficial effect of the [8] vernolate continued the second year because sericea plants were larger and more vigorous, and better able to compete with weeds. It has been customary to plant sericea at high seeding rates and expect no return from it until the following year. Application of vernolate with a low seeding rate (with ample rainfall) permits a cutting of hay in early August or grazing during the year of establishment with only a small reduction in yield the following year. ACKNOWLEDGMENT The assistance of J. K. Boseck and W. B. Webster, Tennessee Valley Substation; J. W. Langford, Plant Breeding Unit, Tallassee; and E. L. Carden and R. F. McCormick, Department of Agronomy and Soils, is gratefully acknowledged. [9] LITERATURE CITED (1) BUCHANAN, (2) C. A. and E. R. BURNS. 1969. Weed control in sericea lespedeza. Auburn Univ. Agr. Exp. Sta. Cir. 165. DONNELLY, E. D. 1963. Serala - a new sericea variety. Agr. Exp. Sta. Leaflet 70. Auburn Univ. (3) HOVELAND, C. S., W. B. ANTHONY, R. R. HARRIS, E. L. MAYTON, and BURGESS. 1969. Serala sericea, Coastal bermuda, Coar tall fescue H. E. grazing for beef cows in Alabama's Piedmont. Auburn Univ. Agr. Exp. Sta. Bull. 388. (4) PATTERSON, R. M., E. D. DONNELLY, and C. W. GANTT. 1967. Broadcast seed for best sericea stand. Auburn Univ. Agr. Exp. Sta. High- lights of Agr. Res. Vol. 14, No. 1. [10] APPENDIX APPENDIX TABLE 1. CHEMICAL, COMMON AND TRADE NAME OF HERBICIDES MENTIONED IN THIS PUBLICATION Common name EPTC___. Chemical name Trade name Eptam' Vernam' S-ethyl dipropylthiocarhamate Vernolate S-propyl dipropylihiocarhamate 1 Trade name of herhicide sold hy Stauffer Chemical Company. - APPENDIX TABLE 2. COMMON AND SCIENTIFIC NAMES MENTIONED IN THIS PUBLICATION OF WEEDS Common name Annual grasses large crahgrass------goosegrass ----------------- Scientific name Digitaria sanguinalis (L.) Scop. Eleusine indica (L.) Gaertn. _Particum ------. fall panicum --------------Broadleaf weeds red root pigweed-----------prickly sida .--------------tall morningglory dichotomifloritm retroflexus L. Michx. .Amaranthus ----------smalifiower morningglory----- _Sida spinosa L. Ipomoea purpurea L. Roth Jacquemontia tamnifolia L. Griseb. [ 11 ] AGRICULTURAL EXPERIMENT STATION SYSTEM OF ALABAMA'S LAND-GRANT UNIVERSITY \Vith an agricultural research unit in every major soil area, Auburn University servxes they needs of field crop, livestock, forestry, and horticultural producers in c each region in Allabama. Ever citizen of the State has a stake in this research program, since any advantage from new and more economical ways of producing and handling ' I 0 ,z 10 > 8 (F farm products directly benefits the consuming public. Research Unit Identification 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. Tennessce Valley Substation, Belle Mina. Sand Mountain Substation, Crossville. North Alabama Horticulture Substation, Cullman. 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, Aitauga 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, Monroevillc Wiregrass Substation, Headland. Brewton Experiment Field, Brewton Ornamental Horticulture Field Station, Spring Hill. Gulf Coast Substation, Fairhope.