Je možné oddálit nástup kvetení meruněk aplikací sójového oleje? [Is it possible to delay bloom of apricots by soybean oil application?]

Apricot orchards are not only in our conditions strongly endangered by the occurrence of late spring frosts. They can have a negative impact on the vitality of the tree, but particularly on the fruit yields. One of the indirect frost protection methods is the bloom delay. Growth regulators, such as ethephon have been used in this research area, but negative effects on treated trees have often been observed. Soybean oil, which is also used as a protection method against overwintering pests, has also been tested as a bloom delayer with varying efficiency. Its single and double application was tested on three apricot varieties. However, the results did not show a greater effect on the bloom delay. The observed delay ranged from 1 to 3 days. Similar results were obtained when Ethrel with the active ingredient ethephon was used alone. The combination of Ethrel with a white paint of the trees and double application of soybean oil was also tested. This combined method resulted in a more significant 5day flowering shift for the ’Darina’ variety. Thus, the application of soybean oil or ethephon alone did not have a significant impact on delaying flowering, but the combination of these treatments seems to be promising.