Alternative Control Method for the Whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) on Soybean Plants

Abstract

Soybean [Glycine max (L.) Merr.] is one of the most important crops cultivated all over the world. The cotton whitefly, Bemisia tabaci (Genn.) is an important piercing sucking insect pest attacking several crops. Using chemical insecticides in pest control causes several problems in the environment and agroecosystems so using non-chemical alternative applications are becoming more needed. The current work examined the effect of using salicylic acid (SA) and sodium meta silicate (SMS) at 2 mM concentration, as inducers, to enhance some biochemical contents and trichome density of soybean plants (Giza 111 and Giza 35 cv.) and their relationship with whitefly biology under laboratory conditions. For each variety, seven treatments were categorized including treated seeds, treated seeds + foliage spray and untreated seeds + foliage spray in addition to untreated check. The results showed that activities of catalase (CAT), polyphenol oxidase (PPO) and peroxidase (POX) increased significantly due to all treatments compared with control in both varieties. Treated seed + foliage spray with SMS induced significantly the highest increase in total protein; by 11.05% and 7.65% for Giza 111 and Giza 35, respectively. Based on biology of whitefly on the two soybean varieties, the results indicated that treated seed + foliage spray with SA and SMS were the most effective treatment against different developmental stages of whitefly from egg to adult. Using chemical inducers such as SA and SMS enhances the resistance of soybean plants and reduces whitefly development.