Evaluation of variety resistance as amangement srategy for thrips (megalurothrips sjostedti trybom and frankliniella occidentalis pergrande) on french beans (phaseolus vulgaris l.)

Abstract

French bean, phaseolllus vulgaris l. is a major horticultural crop in kenya mainly grown for fresh export market. A major contraint in succesfull production of the crop is pests and diseases. thrips are considered as one of the major inscect pests attacking mainly flowers and causing losses of above 60percentage A lot of pesticides use and hence pesticide resideu has been attributed to thrips control. In view of the introduction of maximum pesticides level by importing countries, there is need to develope intergrated thrips mangement strategy with less pesticide use . Towards this goal, nine french beans varieties were evaluated for resistance to thrips (megalurothrips sjostedti frankliniella occidentalis)during the period (november 2001 to april 2002). This was done in two planting phases using randomised complete block design in four replicates. It was evident from the study that there significant diffrences in resistance to thrips by varieties. monel variety was found to be the most susceptibleand impala the least.Frankliniella occidentalis was more abadunt than megalurothrips sjostedti during the study period. The ratio of M . sjostedti to F. occidentalis on flowers was 1.5and 1.7 during the 1st and 2nd planting respectively.