The deposition and retention of a microencapsulated oriental fruit moth pheromone applied as an ultra-low volume spray in the canopy of three peach cultivars

Abstract

Microencapsulated oriental fruit moth pheromone (Checkmate OFM-F) was applied using airblast sprayers at a rate of 15 g a.i./ha either in 635 or 40 litres of water/ha for high-volume and ultra-low volume (ULV) application, respectively. Trials were conducted in peach orchards composed of "Dixired", "Redhaven" and "Glohaven" cultivars in northwestern Turkey in 2006 and 2007. Male moth catches were significantly higher in the insecticide control plots (mean 5.58/week) than those in both high volume (3.38/week) and ULV (1.40/week) pheromone treatments. The ULV application deposited 1.6 times greater number of microcapsules per cm(2) leaf and fruit than the high-volume application. Significantly more microcapsules per cm(2) were deposited on peach leaves (0.06 +/- 0.003) than fruits (0.03 +/- 0.002). "Dixired" leaves and fruits retained significantly more microcapsules per cm(2) than "Redhaven" and "Glohaven" leaves and fruits. The relatively open canopy of "Dixired" may have allowed the accumulation of more pheromone microcapsules around midrib of curved leaves. The differences in microcapsule density did not significantly differ between upper and lower surfaces of peach leaves but leaves in the upper tree canopy had significantly more microcapsules per cm(2) than those in the lower canopy. Unlike leaves, neither fruit surface nor canopy height had any significant effect on the microcapsule deposition on fruits of any cultivar.