Harvest Date Influences Fruit Size and Yield of ‘York’ and ‘Golden Delicious’ Apple Trees

Abstract A delay in apple harvest caused an increase of fruit diameter, weight, price, and crop value, but allowed for increased fruit drop of ‘York’/MM.111. Economic returns for ‘York’ and ‘Golden Delicious’ were increased approximately 16% by delaying harvest by 3 weeks. Crop load of ‘Golden Delicious’/MM.111 trees (from 50 to 120% crop load) did not affect growth rate of fruit in the critical 6.1 to 6.4 cm diameter category. AVG did not influence the rate of ‘Golden Delicious’ fruit growth, but fruit were more firm and had higher starch levels, which allowed for a harvest delay compared to those not treated. Non-treated samples of ‘Golden Delicious’ taken from the same trees in 1997 and 1998 were 32 days more “advanced” in equivalent fruit firmness, 19 days in starch, 11 days in soluble solids, and 21 days in fruit diameter in 1998, thus demonstrating that in some years the normal harvest date could be delayed to gain additional crop value. Sprays of AVG delayed Gala/M.27 fruit ripening which allowed for an increase in fruit size; however, three sprays of Accel at 10 to 20 mm fruit diameter did not cause a delay in maturity or increased fruit diameter.