Effect of cyanamide and DNOC/oil on budbreak, yield and fruit size of Golden Delicious apples

Abstract

Calcium cyanamide (CaCN₂), hydrogen cyanamide (H₂CN₂) and DNOC/oil (dinitro-o-cresol/oil emulsion) were evaluated as rest-breaking agents on Golden Delicious apples during two seasons and in two climatic zones. In the moderate climatic zone, a double and single application of DNOC/oil gave significant improvements in vegetative budbreak and the highest concentration of calcium cyanamide gave a significant improvement in yield relative to the control. In the marginal zone, most treatments significantly increased vegetative budbreak and fruit set but no treatment significantly increased the final yield relative to the control. Considering both cost and efficiency, DNOC/oil applied at the correct time and concentration should be the rest-breaking agent used on mature Golden Delicious trees.