Dissipation of Mefenoxam Residue in Watermelon and Soil Under Field Conditions

Abstract

Mefenoxam is the systemic phenylamide fungicide, which is widely used in controlling phytophthora disease of tomato, cucumber, pepper and watermelon, etc. The dissipation behaviour of mefenoxam residues in watermelons and soils was studied. The whole watermelon, melon flesh and soil matrices of mefenoxam were analyzed by GC-NPD. At three different spiking levels mean recoveries and relative standard deviation from spiked samples in six replicated experiments for each matrix were in the range 89.6-98.2% and 1.5-8.1%, respectively. Under field conditions, mefenoxam dissipation rate was found to be faster in the whole watermelons than in the soils. The results showed that the half lives in whole watermelon and soil from Beijing were 3.9 and 10.0 days, respectively, and the half lives in whole watermelon and soil from Shanxi were 3.7 and 28.4 days.

Identification of sources of seedling resistance to Phytophthora capsici in Cucumis melo

“…The currently available chemical and cultural methods to control P. capsici are neither effective nor economically viable (Lamour et al, 2012). The frequent sprays with fungicides increase the risk of environmental contamination as well as the undesirable occurrence of agrochemical residues in the fruit (Liu et al, 2009). In addition, control based upon fungicide applications can exert a selection pressure on the pathogen, favouring the emergence of tolerant populations (Dunn et al, 2010).…”