Corn oil emulsion for early bloom thinning of trees of 'Delicious' apple,'Feng Huang' peach, and 'Bing' cherry

Corn oil emulsions at 1%, 3%, or 5% were sprayed to 'Delicious' apple, 'Fen g Huang' peach, and 'Bing' cherry trees at prebloom, 20%, 50%, and 80% full bloom (FB), respectively, and the effects of these combinations on bloom t hinning, fruit set, foliage injury, and return bloom were studied. The thin ning effect of oil emulsion was concentration and application time dependen t, with the higher concentration applied earlier being most effective. On a pple and peach trees, 3% to 5% of corn oil applied between prebloom and 20% FB thinned adequately. They were less effective when applied at 50% FB and were not effective at 80% FB. At 1%, oil emulsion was not effective even w hen applied at early stages. In cherries, oil emulsions at 1% and 3% applie d at prebloom to 20% FB thinned fruit to acceptable degrees. Oil at 5%, how ever, over thinned. Oil emulsion was less effective when applied at 50% FB and not effective at 80% FB even at high oil concentrations. Oil at 3% or 5 % applied at 20% FB increased fruit weight and soluble solids but reduced t otal yields in cherries. Oil treatments did not injure fruit or foliage eit her at application or afterwards. Return bloom was not affected in peaches and cherries but was improved in apples by oil treatment.