DETERMINATION OF BIOLOGICAL INSECTICIDE EFFECTIVENESS FOR THE APHIDS AND WHITE FLIES CONTROL IN MELON. LOS SANTOS, PANAMA. 2002.

Abstract

Insect pests are one of melon's major economic constraints, to the point that insecticide applications have been increased. As a result, problems with aphids (Aphis gossypii) and white fly (Bemisia tabaci) are intensified yearly. An experiment was done to evaluate products harmless to beneficial organisms and with low persistence on the environment. A Completely Randomized Block Design with four repetitions was applied. Treatments to be evaluated were Metasav (Metharrizium anisopliae), Biocrack (garlic based extract), imidacloprid (chemical control) and a Check without pests control. Three imidacloprid applications (2, 27 and 39 dat) and seven Metasav and Biocrack applications were tested. Sampling was done to estimate pests populations and to assess biological efficacy of treatments. Evaluated variables were: yield of fruits, plants and fruits harvested, fruits per plant and aphid and white fly populations. Square root transformation was applied to aphid and white fly populations. Statistical analysis of aphid population revealed highly significant differences (P<0.01) starting from samples taken on february 22 (20 dat). Metasav showed good aphid control while Biocrack's effectivity was reduced, starting from march 8 sampling. Same results were found for white fly. Highest yield, 42.83 t/ha, was obtained with imidacloprid, followed by Metasav (31.36 t/ha) and Biocrack (23.33 t/ha) treatments. Lowest yield was the result of no pest control by elimination of plants due to aphid attack.