Some Cultural Strategies to Help ManageBemisia Tabaci(Hemiptera: Aleyrodidae) and Whitefly-Transmitted Viruses in Vegetable Crops

Abstract

The sweetpotato whitefly, Bemisia tabaci (Gennadius), is an important global pest of numerous crops as a result of its feeding and whitefly-transmitted plant viruses. To help develop a strategy to manage this pest and associated viruses in three vegetable crops in the Egyptian agricultural system, experiments on several cultural techniques were conducted. Cultural practices of mulching with white polyethylene, intercropping with maize (Zea mays L.), and crop rotation with maize resulted in reduced whitefly populations and reduced incidences of viruses in cucumber (Cucumis sativus L.), squash (Cucurbita pepo L.) and tomato (Solanum lycopersicum L.). However, no benefit in whitefly abundance and virus incidence was obtained from modifying the planting time by one month earlier than standard planting. There was a high correlation between whitefly abundance and virus incidence. Based on viral symptoms, up to 75 % infection was observed in untreated plots, while most of the treated plots had less than 40 % infection. The viruses affecting the crops were Cucumber vein yellowing virus in cucumber, Squash leaf curl virus in squash, and Tomato yellow leaf curl virus in tomato; they are common problems in Egypt. The first-mentioned virus is caused by an Ipomovirus in the family Potyviridae while the other two are Begomovirus in the family Geminiviridae. The cultural management strategies utilized in this study are viable tools to help manage B. tabaci and associated viruses in vegetable crops.