Organochlorine pesticide residues - a review of some recent findings

Investigations to determine the optimum timing and placement of a supplementary food spray, Envirofeast® on the abundance of predatory insects on cotton was conducted in irrigated commercial cotton fields at Yarral near Narrabri, New South Wales, Australia, in 1998 v - v 99. Plots treated with the supplementary food product at the four-true leaf stage recorded a significantly higher number of predatory beetles, bugs and lacewings per metre compared with plots treated at two, six and eight-true leaf stages and unsprayed (control) plots. The cumulative total number of predatory beetles, bugs and lacewings recorded throughout the season in both treated and control plots was 23.81 per m. Of this total, plots treated at four true leaf stage recorded the highest (7.15 per v m) (i.e 30.03%), followed by two true leaf (5.81 per m) (24.41%), six true-leaf (4.31 per v m (18.12%), eight true-leaf stage (4.63 per v m) (i.e. 19.44%) and the unsprayed (control) plot recorded the lowest (1.91 per m (8.03%). The number of spiders per metre were not significantly different ( p v > v 0.05) among treatments and the control plots. The number of predators recorded in cotton crops treated with the supplementary food product as a band spray (33 v - v 50% band) or skip row spray (i.e. to every second row) was not significantly different ( p v > v 0.05) from plots where the product was applied as a solid spray to the entire crop (no skip row and/or no banding). Thus, tailoring Envirofeast® treatment in this way will ultimately reduce the quantity of product used, the cost of the product and allow cotton growers to adopt a multiple-use pattern for the product to support integrated pest management programmes in cotton.