Agron. Sustain. Dev.
Volume 26, Number 1, January-March 2006
Page(s) 55 - 59
Published online 24 January 2006
Agron. Sustain. Dev. 26 (2006) 55-59
DOI: 10.1051/agro:2005060

Antibiosis of forage soybean as an ecological alternative for the control of corn earworm

Iqbal Javaid, Robert B. Dadson, Fawzy M. Hashem and Jagmohan Joshi

Department of Agriculture, University of Maryland Eastern Shore, Crop Research and Aquaculture Building, 30921 Martin Court, Princess Anne, MD 21853-1299, USA

(Accepted 25 October 2005; published online 24 January 2006)

Abstract - The present study is the first to document some antibiosis type of resistance in forage soybeans. The production of forage soybean is increasing in the United States where about 500 000 acres are now grown annually in various soybean growing areas. However, production is limited by the corn earworm Helicoverpa zea Boddie, which is a major insect pest of soybean. An in vitro study of field grown soybean leaves was conducted to select forage soybean genotypes for antibiosis type resistance to corn earworm. The feeding tests were conducted on excised leaf material from a randomized complete block design. The results showed significant differences in the weight of corn earworm larvae, which were allowed to feed on different genotypes of fodder soybean. The mean larval weights on genotypes Tara, 7P116 and 8 GH 85-2 were 245.8, 242.1, and 169.3 mg, respectively. These genotypes were found to be most susceptible to corn earworm while the tall growing vegetable cultivar Moon Cake with the mean larval weight of 94.8 showed some antibiosis types of resistance.

Key words: antibiosis / corn earworm / forage soybean / host plant resistance

Corresponding author: Iqbal Javaid

© INRA, EDP Sciences 2006