Comparison of Bacillus thuringiensis corn hybrids and insecticide-treated isolines exposed to bivoltine European corn borer (Lepidoptera: Crambidae) in South Dakota.
The performances of Bacillus thuringiensis (Bt) corn hybrids and permethrin-treated isolines were evaluated in South Dakota from 1997 to 1999. The corn hybrids were exposed to natural seasonal fluctuations of a bivoltine ecotype European corn borer population. Larval injury parameters, grain yields, and gross incomes were quantified during the 3-yr study. The use of either Bt hybrids or whorl-applied permethrin granules resulted in significant yield advantages in only 1 out of 3 yr of performance testing. Under high corn borer pressure in 1997, the performances of the Bt corn hybrids and permethrin-treated isolines were similar, and significantly better than the untreated isolines. However, injury-free corn did not necessarily translate into higher yields in some of the hybrid groups. Grain moisture at harvest, which can result in moisture penalty or dockage, was significantly higher in some Bt corn hybrids. Neither the Bt hybrids nor the permethrin-treated isolines produced significant advantages in yields in 1998 and 1999 when infestations of first-generation corn borer were almost nonexistent and infestations of second-generation European corn borers were moderate.
Catangui
Michael A
MA
Department of Plant Science, South Dakota State University, Brookings 57007-1096, USA. michael_catangui@sdstate.edu
Berg
Robert K
RK
D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics / Q000502:physiology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001427:Bacterial Toxins / Q000235:genetics; D018556:Crops, Agricultural / Q000191:economics; D004731:Endotoxins / Q000235:genetics / Q000502:physiology*; D005060:Europe; D006460:Hemolysin Proteins; D007306:Insecticides; D009036:Moths / Q000502:physiology*; D026023:Permethrin; D010572:Pest Control, Biological / Q000191:economics / Q000379:methods; D030821:Plants, Genetically Modified; D013023:South Dakota; D003313:Zea mays
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D026023:Permethrin