Response of Bt and Non-Bt Cottons to High Infestations of Bollworm (Helicoverpa zea Boddie) and Tobacco Budworm (Heliothis virescens (F.)) under Sprayed and Unsprayed Conditions

Autor: Kerry C. Allen, Randall G. Luttrell, Nathan S. Little, Katherine A. Parys, Omaththage P. Perera
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Agronomy, Vol 9, Iss 11, p 759 (2019)
Druh dokumentu: article
ISSN: 2073-4395
DOI: 10.3390/agronomy9110759
Popis: Early-maturing and full-season Bt and non-Bt cottons were exposed to high densities of tobacco budworm (Heliothis virescens (F.)) and bollworm (Helicoverpa zea Boddie) in 0.04 ha field cages during the summers of 2011 and 2012 to measure the possible need for supplemental use of insecticides on Bt cotton. Fruit survival within-season and at-harvest was carefully mapped on individual plants within comparative plots of all cottons untreated and sprayed with lambda-cyhalothin (0.0448 kg a.i./ha) or chlorantraniliprole (0.1009 kg a.i./ha) following insect infestations. Differences in lint yields among cotton maturity groups were not always detected, but early-maturing Bt cottons were among the higher yielding experimental plots for both years. Depending on the insecticide treatment, average harvested fruit ranged from 0.3 to 7.1 open bolls per plant for non-Bt cotton plots, while Bt cotton plots ranged from 1.8 to 7.5 open bolls per plant during the two-year study. Bt cottons generally protected fruit from insect damage and resulted in final yields comparable to those of insecticide sprayed Bt and non-Bt cottons. Unsprayed non-Bt cottons were significantly damaged by insects in these high-infestation environments.
Databáze: Directory of Open Access Journals
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