Final Report for FNE93-031
Note to readers, attached is the complete final report for FNE93-031.
Spray volumes per acre were reduced 10.2%-49.7% in the block where the crop care system was used, resulting in a savings of $59.59 per acre in pesticide costs. Savings with the crop care system increased after pruning the trees to the "Christmas-tree", pyramid shape to eliminate low, over-hanging limbs that had caused the top sonar "eyes" to sense foliage in the tops of the trees when this wasn't really the case. In addition, time savings by allowing the operator to treat more acres with a tank load of spray solution would be realized.
Apple scab was higher in the block where the crop care system was used, but the scab was late-appearing lesions that did not affect the processing quality of the fruit. Oblique-banded leafrollers caused damage in both blocks and processing grades showed 1% damage in both blocks. The OBLR damage was caused by delaying the control spray for too long so that it was not effective on the larger larvae. This grower decision was based on previous experience where similar OBLR levels had not caused any financial loss. As with any system that offers these levels of cost savings, the system will require a higher level of knowledge of what is happening in the block, and less tolerance for problems when they are identified.