The influence of growth regulators on the increasing of resistance of reproductive bodies at low temperatures in blossoming period of some pear varieties

Abstract

The experimental plot it was placed in the orchard „Terra Vitis” Ltd. founded in 2010 year. The research was conducted during the period of 2017 year. The study subject of the experience was ‘Vistavocinaia‘ and ‘Noiabrskaia‘ pear varieties, grafted on BA 29. The trees were trained as spindle system. The distance of plantation is 4.0 x 2.0 m. To study setting processes of reproductive organs, fruit production and its quality were experimented the following variants of treatment: 1. Control - without treatment; 2. GA3 - 20 ppm (18.04.2017); 3. Prohexadione de Ca - 10 ppm + GA4+7 - 40 ppm (26.04.2017). During the research, it was studied degree of fruit setting, average of fruits, plantation production and their quality. It was established that the growth regulator GA3 in dose of 20 ppm can be included in the technology system when 30-60% of the flowers are open to increase the resistance of the reproductive organs at low temperatures, improving the physiological processes in the plant, increasing the degree of fruit setting, the amount of fruit in the pear tree crown and plantation production.