Fruit growing
and viticulture of South Russia

Annotation

The research was carried out on the basis of the laboratory of physiology of fruit stability plants of VNIISPK in 2016-2017. The objects of the research were apple cultivars selected by the Institute and growing on a semi-dwarf rootstock 54-118. The variety of Antonovka Obyknovennaya was taken as a control. The experiments were started in 2013, with the scheme of the trees plantings is 5 � 3 m. The crown was spindle�shaped. The row-spacing and trunk strips were kept under black steam. To determine the heat resistance of apple cultivars, the method of heat shock +50 ºC (1.5 hours) was used. The purpose of the research was to study the heat resistance of apple cultivars based on determining the parameters of the water regime in the laboratory. The following parameters of the water regime were determined: total hydration, water deficit, restoration of leaf hydration. As a result of two-year studies, the studied apple cultivars were characterized by average water content (61.2...64.9 %), low water deficit under the field conditions and average deficit after exposure to heat shock and high ability to restore water content of leaf tissues (85.2...108.1%) after exposure to high temperature. The distribution of precipitations and temperatures under the field conditions during the passage of the studied cultivars of individual phenophases affected the hydration and water deficit of apple leaf tissues. There was a decrease in total water content and an increase in water deficit of leaves tissues during the fruit formation period (August) and during the onset of dry and hot conditions in the summer period. After exposure to high temperature +50 ºC in the laboratory conditions, the leaves showed an increase in water deficit in apple cultivars compared to the data under the field conditions. It was found that all the studied apple cultivars had an average level of heat resistance at the level of the control cultivar of Antonovka Obyknovennaya.