Evaluation of Organic Pest Controls and Fruit Thinning on Multiple Apple Cultivars
Disease and insect control strategies suitable for organic farmers were evaluated in an apple variety block that contained 15 different cultivars. The organic treatments were compared to similar sets of trees that received either standard pest management treatments or were left unsprayed. Effectiveness of pest control programs and their impact on productivity was evaluated for 33 different parameters on each of the 15 cultivars. Due to the high insect and disease pressure in this orchard, neither the standard nor the organic treatments provided commercially acceptable levels of pest control. Insect damage was found on 41 to 53% of fruit at harvest, but the organic and standard programs were comparable for most of the insect pests evaluated. However, the standard program was more effective for controlling black rot, bitter rot, and lenticel spotting caused by Botryosphaeria species. Pesticides plus application costs totaled $650/A for the standard program as compared to $1,173/A for the organic program. Total yield per acre (including fruit damaged by pests) was 209, 409, and 861 bushels per acre for the unsprayed, organic, and standard treatments, respectively. Pest control costs per bushel were $2.98 for fruit from the organic block compared to $0.76 for the standard. Results from this trial show that pest-free apples can be produced organically in New York, but organic producers will likely need at least a 400% sales premium compared to standard growers due to the high costs and reduced yield associated with organic pest control. Further research may lead to cost reductions and improved productivity for organic systems, but farmers currently considering a switch to organic apple production should verify that their prospective produce buyers will be willing to pay a significant premium for organic fruit.