SPECIES COMPOSITION AND OCCURRENCE OF THRIPS ON TOMATO AND PEPPER AS INFLUENCED BY FARMERS'MANAGEMENT PRACTICES IN UGANDA

摘要

A biological monitoring survey was carried out in central Uganda for two consecutive seasons to provide information on species composition and occurrence of thrips on tomato and pepper as influenced by farmers' management practices. A total of 50 farms for each crop participated in the study. Data was collected on cropping system, crop variety, type of pesticide used, pesticide spray regime, and on thrips populations. Results indicated that a total of six thrips species: Frankliniella occidentalis, Thrips tabaci, F. schultzei, Scirtothrips dorsalis, Ceratothrips ericae and Megalurothrips sjostedti infest tomato in the region. Pepper had the same thrips profile with the exception of F. schultzei. There was a distinct seasonal effect on thrips occurrence in the case of tomato. Higher thrips populations (61%) were recorded in the first season of the study as compared to the second. The majority of the thrips were recorded in the flowering stage of crop development for both crops, and 100% in the caseof pepper. Generally, for both crops, plants in intercropped arrangements had higher thrips counts than the monocropped ones. Different tomato/pepper varieties sustained variable thrips populations. All the farmers applied pesticides to manage the complex of pests on the crops, albeit to variable extents. In this region, thrips populations were reduced when an increase in the number of pesticide applications in a given week was used.