Spray deposition and abscission efficacy of CMN-Pyrazole in mechanical harvesting of valencia orange

Abstract

Tests were conducted to investigate the efficacy of an experimental abscission chemical, CMN-Pyrazole (CMN-P), in a commercial orange grove in south Florida. Application variables included sprayer type, spray volume rate, spray release height, and application time. Spray deposition was assessed by fluorometry and the chemical efficacy was quantified by measuring fruit detachment force and fruit removal by a trunk shaker. CMN-P deposition decreased when spray volume increased. However, high volume applications produced better loosening effects and fruit removal. At low volumes, nighttime application resulted in higher depositions than daytime application. Spray release height had significant effects on spray penetration within the canopy, fruit detachment force, and fruit removal. Depositions on the outside and at lower canopy locations were generally higher than those on the inside and at higher canopy locations.