Cabbage Flea Beetles, Phyllotretaspp (Coleoptera: Chrysomelidae) Management on Ethiopian Mustard, Brassica carinata A. Braun, in Arsi Zone, Oromia

Abstract

The effect of varying seed rate and screening o f insecticides were done in Kulumsa Agricultural Research Center by sowing Yellow Dodolla mustard in year 2011. The experiments were laid-out in a randomized complete block design (RCBD) with four replications. Two rows o f lm length were used fo r sampling o f flea beetles and their damage. Yield was obtained from 1.5m x 2m area o f each plot and expressed in kg/ha. The six seed rates revealed no significant difference in mean number of flea beetles but the mean number o f damaged plants was found to be decreased from plots sown with the lowest to the highest seed rates fo r all phonological stages o f the crop. Productive plants and plant population reduction were maximum fo r plots o f the highest seed rate (10.8g) and minimum fo r the lowest (2.7g) seed rate. Maximum mean seed yield (1917.8kg/ha) was obtained from plots sown with seed rate of 5.4g (lOkg/ha). The higher rate of Carbaryl, Maiathion and the two rates o f Fenitrothion reduced significantly the mean number of flea beetles and the damage (P<0.05) they caused to the plant. Productive plants and yield (kg/ha) were higher fo r plots treated with higher rate o f Carbaryl, Maiathion and lower rate o f Fenitrothion. This study generally revealed that the recommended rate of seed rate and Fenitrothion at its recommended rate can be used in cabbage flea beetle management.