The effects of a summer spray of succinic acid-2, 2-dimethylhydrazide on the incidence of physiological disorders and quality of Jonathan and Delicious apples after cool storage

Abstract

A foliar spray of succinic acid-2, 2-dimethylhydrazide (daminozide) applied in late summer to Delicious and Jonathan apples delayed fruit maturity and softening in subsequent storage. This difference was usually retained throughout storage especially with Jonathan. Development of superficial scald was effectively delayed in stored Delicious. Jonathan spot, and, to a lesser extent, low temperature breakdown, were reduced in Jonathan. After three consecutive years of application at 1000 p.p.m. there was no reduction in effects on firmness or breakdown in Delicious. There was also a carryover effect into the third season when daminozide at 1500 p.p.m. was applied in the first two years but not used in the third.