Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-24T11:06:05.243Z Has data issue: false hasContentIssue false

PRODUCTIVITY AND PERSISTENCE OF DECLINING ALFALFA STANDS AS INFLUENCED BY THE ALFALFA WEEVIL, WEEDS, AND EARLY FIRST HARVEST IN OKLAHOMA

Published online by Cambridge University Press:  31 May 2012

M.A. Latheef
Affiliation:
Departments of Entomology, Agronomy and Statistics, Oklahoma State University, Stillwater, Oklahoma, USA74078
R.C. Berberet
Affiliation:
Departments of Entomology, Agronomy and Statistics, Oklahoma State University, Stillwater, Oklahoma, USA74078
J.F. Stritzke
Affiliation:
Departments of Entomology, Agronomy and Statistics, Oklahoma State University, Stillwater, Oklahoma, USA74078
J.L. Caddel
Affiliation:
Departments of Entomology, Agronomy and Statistics, Oklahoma State University, Stillwater, Oklahoma, USA74078
R.W. McNew
Affiliation:
Departments of Entomology, Agronomy and Statistics, Oklahoma State University, Stillwater, Oklahoma, USA74078

Abstract

Importance of cultivars, harvest schedules, and pest infestations as determinants of alfalfa, Medicago sativa L., productivity and stand persistence was investigated using the unimproved “OK08” (Oklahoma Common) and the multiple-pest resistant “WL 318” cultivars. Beginning in the 5th year of production, treatments including three first-harvest schedules (early bud, early bloom, and full bloom) were imposed in a factorial arrangement with unsprayed subplots and three pesticide options for control of alfalfa weevil, Hypera postica (Gyllenhal), or weeds such as downy brome, Bromus tectorum L., or both. In addition to estimating population levels of alfalfa weevil and percentage composition of weeds in forage during each year, alfalfa dry matter yield and stem densities (no. per square metre) were determined during the 3-year period from 1986 through 1988. The seasonal forage production (2-year mean) of WL 318 was nearly 5.4 Mg per hectare greater than that of OK08. There was no consistent trend for greater seasonal alfalfa yield with any of the first-harvest schedules. Timely application of pesticides, as well as use of the improved cultivar were essential for maintaining productivity in years 5 through 7 of stand life. At the termination of the study, only the herbicide + insecticide treatment of WL 318 had close to sufficient stem (and plant) numbers remaining for continued production.

Résumé

L’influence de la nature des cultivars, du calendrier des récoltes et des infestations d’organismes nuisibles sur la productivité et la survie des cultures de luzerne, Medicago sativa L., a fait l’objet d’une étude au cours de laquelle les cultivars OK08 (Oklahoma Common) non amélioré et WL 318 résistant à plusieurs organismes ont été utilisés. Au cours de la 5ème année de production, divers traitements, notamment trois calendriers de première récolte (début du bourgeonnement, début de la floraison, faîte de la floraison), ont été essayés. Ces traitements ont été imposés selon un arrangement factoriel sur des grilles-échantillons non vaporisées et sur des grilles-échantillons vaporisées selon trois options d’arrosage au moyen de pesticides destinés au contrôle du Charançon postiche de la luzerne, Hypera postica (Gyllenhal), ou au contrôle de mauvaises herbes telles le brome des toits, Bromus tectorum L., ou au contrôle des deux. En plus de mesurer les densités de population du charançon et la composition en pourcent des mauvaises herbes dans les récoltes chaque année, nous avons déterminé la production de luzerne (masse sèche) et la densité des tiges (nombre par mètre carré) au cours d’une période de 3 ans, de 1986 à 1988. La production saisonnière (moyenne de 2 ans) de luzerne de type WL 318 s’est avérée de près de 5,4 Mg par hectare plus élevée que celle de la luzerne de type OK08. La date de la première récolte n’affectait pas de façon particulière la production saisonnière de luzerne. Deux facteurs, l’application de pesticides à des moments précis et l’utilisation de cultivars améliorés, se sont avérés essentiels à l’obtention d’une productivité stable au cours des années 5 à 7 de la vie de la culture. A la fin de l’étude, seules les grilles échantillons de WL 318 traitées à l’herbicide + insecticide avaient encore des nombres suffisants de tiges (et de plants) pour assurer une production continue.

[Traduit par la rédaction]

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Beard, D.F., and Kawaguchi, I.I.. 1978. Registration of WL 311 and WL 318 alfalfa cultivars. Crop Sci. 18: 523.CrossRefGoogle Scholar
Berberet, R.C., Morrison, R.D., and Senst, K.M.. 1981. Impact of the alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), on forage production in nonirrigated alfalfa in the southern plains. J. Kansas ent. Soc. 54: 312318.Google Scholar
Berberet, R.C., Senst, K.M., Nuss, K.E., and Gibson, W.P.. 1980. Alfalfa weevil in Oklahoma: The first ten years. Oklahoma Agric. Exp. Stn. Bull. B-751.Google Scholar
Berberet, R.C., Stritzke, J.F., and Dowdy, A.K.. 1987. Interactions between alfalfa weevil (Coleoptera: Curculionidae) and weeds in reducing yield and stand of alfalfa. J. econ. Ent. 80: 13061313.CrossRefGoogle Scholar
Godfrey, L.D., and Yeargan, K.V.. 1987. Effects and interactions of early season pests on alfalfa yield in Kentucky. J. econ. Ent. 80: 248256.CrossRefGoogle Scholar
Godfrey, L.D., and Yeargan, K.V.. 1989. Effects of Clover root curculio, alfalfa weevil (Coleoptera: Curculionidae), and soil-borne fungi on alfalfa stand density and longevity in Kentucky. J. econ. Ent. 82: 17491756.CrossRefGoogle Scholar
Hsieh, F., and Armbrust, E.J.. 1974. Temperature limits of alfalfa weevil oviposition and egg density in Illinois. J. econ. Ent. 67: 203206.CrossRefGoogle ScholarPubMed
Lamp, W.O., Yeargan, K.V., Norris, R.F., Summers, C.G., and Gilchrist, D.G.. 1985. Multiple pest interactions in alfalfa. pp. 345364in Frisbie, R.E., and Adkisson, P.L. (Eds.), IPM on Major Agricultural Systems Symposium. Texas Agric. Exp. Stn. Publ. MP-1616.Google Scholar
Latheef, M.A., Caddel, J.L., Berberet, R.C., and Stritzke, J.F.. 1988 a. Alfalfa forage yield, stand persistence, and weed colonization as influenced by variable first harvest in Oklahoma. J. Prod. Agric. 1: 155159.CrossRefGoogle Scholar
Latheef, M.A., Caddel, J.L., Berberet, R.C., and Stritzke, J.F.. 1988 b. Alfalfa production as influenced by pest stress and early first harvest in Oklahoma. Crop Prot. 7: 190197.CrossRefGoogle Scholar
Norris, R.J., Cothran, W.R., and Burton, V.E.. 1984. Interactions between winter annual weeds and Egyptian alfalfa weevil (Coleoptera: Curculionidae) in alfalfa. J. econ. Ent. 77: 4352.CrossRefGoogle Scholar
Rommann, L.M., Caddel, J.L., Williams, E. Jr, and Berberet, R.C.. 1984. Alfalfa varieties for Oklahoma. OSU Extension Facts 2078. Oklahoma State Univ. Coop. Ext. Serv.Google Scholar
SAS Institute. 1988. SAS User's Guide: Statistics. SAS Institute, Cary, NC.Google Scholar
Steel, R.G.D., and Torrie, J.H.. 1980. Principles and Procedures of Statistics, 2nd ed. McGraw-Hill, New York, NY.Google Scholar
Walton, P.D. 1983. Production and Management of Cultivated Forages. Reston Publishing Co., Reston, VA.Google Scholar
Woodall, T.K. 1987. Effects of fall forage removal and pesticide treatments on weeds in alfalfa. M.S. thesis, Oklahoma State University, Stillwater, OK.Google Scholar