Effect of Alar on Bloom Date of Richared Apples

Abstract

Late spring frosts are one of the hazards confronting New Mexico apple growers. Orchard heating is generally required if full crops are to be obtained. A delay in blossoming of a few days may, in many years, reduce or eliminate the need for orchard heating. Rather extensive experimental work has been done with the growth retarding compound, N-dimethyl amino succinamic acid (Alar). It has been reported to suppress terminal growth of apple trees, increase red color and firmness of fruit, and reduce fruit drop. Limited reports indicate that Alar may be useful in retarding bloom. Fall applications of Alar delayed blossoming of Bartlett pears the following spring (2). Pre-bloom sprays of Alar resulted in one to three days in blossoming of apples (1).