IMPROVING ECONOMIC AND ENVIRONMENTAL SUSTAINABILITY IN TREE-FRUIT PRODUCTION THROUGH CHANGES IN ROOTSTOCK USE

With the highly competitive market, demand for high quality fruit by consumers, pressure to reduce chemical use, and a need to enhance the economic efficiency of production, tree-fruit growers must look to economically and environmentally sustainable management schemes of production. Growers who want to stay profitable must establish high-density plantings with smaller trees using new cultivars. High-density plantings cost more to establish than low density plantings, thus increasing economic risk. Potential returns of high-density plantings, however, far exceed those of low-density plantings, particularly during the first 10 years. The central component of a high-density system is the rootstock, which provides control of final tree size allowing for closer tree spacing and greater number of trees per land area. The rootstock also influences productivity, fruit quality, pest resistance, stress tolerance, and profitability. Size-controlling rootstocks are lacking for many fruit crops, and those rootstocks that are available have inherent weaknesses. Past research has identified efficient rootstocks for apple and cherry, but inefficient rootstocks remain a problem for other tree fruits. Continued tree losses due to cold temperature injury, disease, scion incompatibility, and poor soil conditions are an economic cost for the industry that can be ameliorated by improving rootstock choices for growers. NC-140 recommendations and educational programs will guide the planting of 200,000 acres of fruit trees in the next 5 years, resulting in a more economically and environmentally sustainable fruit industry. By utilizing NC-140 recommended rootstocks, farmers will receive earlier returns on investments related to orchard establishment. With NC-140 recommended rootstocks, mature yields will increase by 20%, fruit size by 10%, and the percent meeting the highest grade category by 20%. The financial benefit to U.S. fruit growers from earlier returns, greater yield, and higher fruit quality will be $250,000,000 as a direct result of the use of NC-140 recommendations.The use of NC-140 recommended rootstocks will result in a 50% reduction in canopy volume and a concomitant 50% reduction in pesticide usage on 200,000 acres. The reduction in pesticide use will net environmental benefits and save $150,000,000 in pesticide cost and application. Because of the use of NC-140 recommended, disease-resistant rootstocks and better selection of susceptible rootstocks, tree losses will decline by 10%. Cumulative, measurable benefits to the U.S. temperate tree-fruit industries will be more than $400,000,000. Less easily measured benefits, such as averted losses and enhanced environmental quality, will increase the financial value of NC-140 to well beyond $500,000,000 in the next 5 years.