Efficiacy of some plant growth regulatory substances and kaoline and fogging applications on flowering time, yield and quality of hacihaliloğlu apricot variety

The biggest problem encountered in apricot growing regions in the world and in our country is late spring frosts. This study was conducted at the Malatya Apricot Research Institute Directorate between 2016 and 2019. The effects of some plant growth regulators, kaolin and fogging applications on yield and quality by delaying the flowering time of the dried Hacıhaliloğlu apricot variety, which is the most produced in the world and in our country, were investigated. 100 ppm etefon application applied during the defoliation period of 2016 delayed the flowering date by 2 days, 200 ppm by 3 days and 400 ppm by 5 days. 100 ppm etefon application applied during the defoliation period of 2018 delayed the flowering time by 4 days, and 200 ppm by 2 days. GA4+7+GA3 200+100 ppm doses applied in both years delayed flowering by one day. Pro-Ca, a gibberellin inhibitor, contrary to expectations, either did not change the flowering time or brought it forward by 1 day. While kaolin application delayed the full flowering time by 1-2 days, fogging application on the trees delayed the flowering time by 9-11 days. Gibberellin applications applied in the autumn period caused thinning of the plant but also increased fruit size. Ethephon 100 ppm dose delayed the flowering time and had a thinning effect on the fruits without causing stress on the trees. As a result of the study, the fogging application among all applications prevented the loss of yield and quality due to late spring frost that occurred during the flowering period in 2019. For this reason, it is recommended to apply fogging via overhead sprinklers to dwarf/semi-dwarf apricot orchards.