Optimization of Heat Stress Mitigation Measures for Strawberry Plug Transplant Establishment

摘要

The Florida strawberry (Fragaria xananassa Duch.) industry continues to experience competition for the winter market from California; but of particular concern has been Mexico where strawberry acreage has been expanding. Moving Florida strawberry production to earlier in the season to take advantage of the higher prices for early yield may improve the state's economic sustainability. Early planting in Florida, however, exposes strawberry transplants to heat stress. In order to address the problem ofheat stress in a system designed to eliminate the use of overhead irrigation for strawberry transplant establishment, the utility of s-ABA and kaolin on 'Florida Radiance' strawberry plugs was assessed. In the first year s-ABA was applied at 250,500,750,and 1000 mg/L as a five-second root dip just prior to transplanting. Because of adverse outcomes, which were worse at the higher rates, s-ABA application rates were decreased to 100,150,200, and 250 mg/L in the second year. Kaolin (56 kg/ha) was appliedin both years as either a single spray shortly after transplanting or as two consecutive sprays—the first at the same time as the single spray application and the second at seven days after transplanting. The results indicate that plug transplants treated with either 100 mg/L s-ABA treatment or with single or double kaolin sprays exhibited better survival, vigor, vegetative growth, and early marketable yield than untreated transplants.