GROWTH ACTIVITY OF APPLE TREE ORCHARDS UNDER A HAIL-PROTECTIVE NET AT DIFFERENT SOIL MANAGEMENT SYSTEMS

Abstract

An anti-hail net is an effective protection of fruit orchards from hail, sunburn and bird damage. The grid slightly changes the microclimate of plantations and, as a consequence, the activity of tree growth. The purpose of the study was to evaluate the growth activity of the intensive apple orchards, cv. Jonagold (Wilmuta), on dwarf rootstock M.9 T337. The soil management system in the inter-rows was the following: a grass mowed stripe and black fallow in the inter-rows, herbicide fallow and spring mulching with a two-layer agro-cloth of 30 + 50 g / m2 density (a white side up) and a lightreflective film in the tree-strips one meter wide which was spread one month before harvesting. After flowering, a black anti-hail net with 0.3 x 0.3 cm cells and a density of 0.08 kg / m2 was spread above the tree crowns at a height of 3.4 m. It was found out that the increase in the trunk girth did not exceed 0.36 cm and did not significantly depend on the factors studied. During the study period, the increase in the girth of the trunk on the plots with a grass mowed stripe in the inter-rows exceeded the same rate of the plots under black fallow in the inter-rows by 19.3%. The number of one-year apple shoots in the plots without a net with pure fallow in the rows and agro-cloth in the tree-stripes exceeded the indicator of the plots under an anti-hail net with a grass mowed stripe in the inter-rows and herbicide fallow in the stem stripes.The value of this indicator was mostly influenced by the method of the stem stripe management - 13.8%. As compared to the indicators under the net, the shoots were a third longer in the plots without the anti-hail net with black fallow in the inter-rows and herbicide fallow or a light-reflective film in the stem stripes. On average, over the years of research shoots were 11% longer in the plots without a grid, as well as with black fallow in the inter-rows. In general, in the areas covered with a net with black fallow in the inter-rows, the shoots were shorter and their total length was 10-12.3% less.The one-year increase in the girth of the tree trunk was 19% higher on the grass mowed stripe in the interrows, and the number of shoots was 17% higher in the tree-stripes with agro-cloth.