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

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

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.

Mots clés: antibiosis; corn earworm; forage soybean; host plant resistance

Domaines: Sciences agricoles; Ecologie, Environnement

Iqbal Javaid, Robert B. Dadson, Fawzy M. Hashem, Jagmohan Joshi. Antibiosis of forage soybean as an ecological alternative for the control of corn earworm. Agronomy for Sustainable Development, 2006, 26 (1), pp.55-59. ⟨hal-00886322⟩