Effect of some biorational insecticides on Spodoptera eridania in organic cabbage

BACKGROUND: To reduce pest attack, several biorational products are allowed for use on organic vegetables in Brazil. This study investigated eight biorational products applied singly or in combination against Spodoptera eridania Cramer in field plots of cabbage intercropped with coriander. The treatments were applied once a week over a 5 week period, beginning 34 days after transplanting. The evaluations consisted of counting the larvae of S. eridania on the day before and 7 and 21 days after spraying. The damage to leaves and cabbage head, the commercial weight of head and the percentage of head losses were evaluated. RESULTS: Leaf injury in plots treated with Beauveria bassiana and neem oil (Dalneem) yielded scores of 1.3 and 2.5 (scale ranging from 0 to 4) respectively, in comparison with a score of 3.6 from untreated plots. Head weight losses were 6.1, 5.3 and 4.9% with an aqueous extract of neem leaves, neem oil and B. bassiana respectively, compared with 24.6% lost from untreated plots. CONCLUSION: Dalneem((R)), B. bassiana and the extract of neem leaves at 20% exhibited the best performance for control of S. eridania. (c) 2008 Society of Chemical Industry.