APPLE TREES PRODUCTIVITY UNDER THE HAIL-PROTECTIVE NET IN DIFFERENT SOIL MANAGEMENT SYSTEMS

Abstract

Effective growing of horticultural products is achieved by the protection against extreme factors, such as hail and sunburn, which becomes especially relevant in the face of climate change. The article highlights the effect of the black anti-hail net on the yield and quality of the fruit in the irrigated apple orchard on the dwarf rootstock. The purpose of the study is to comprehensively evaluate the effectiveness of hail protection and to improve the quality of apples by a rational soil management system in the inter-rows and the strips in the tree rows. The studies were conducted in a fruitful orchard with a 4×1 m planting scheme and the formation of trees by a slender spindle type. The soil management system in the inter-rows was the following: a grass mowed stripe, herbicide fallow in the inter-rows, spring mulching with a two-layer agro-cloth of 30+50 g/m2 density (a white side up) and a light-reflective film in the tree-strips one meter wide spread one month before harvesting. After flowering, a black anti-hail net with 0.3×0.3 cm cells and a density of 0.08 kg/m2 was deployed above the tree crowns at a height of 3.4 m. It has been found out that a black anti-hail net has a negligible effect on the productivity of irrigated apple-tree orchards of cv. Jonagold (Wilmuta) on M.9 T337 rootstock, but the total yield of trees under the net was 4.1 % lower. Among the studied methods of soil retention, it was 5.8 % higher in the plots with grass mowed inter-rows as compared with black fallow, but regularities in high-yield seasons were not established. In the first year, 64.8 % were more productive areas with grass mowed inter-rows, and in the next year – on the contrary - steam-planted plantations were a third more productive. Crop capacity does not depend much on the mulching of the strips in the tree rows with agro-cloth or light-reflective films. In general, under black fallow or grass-mowed alleys and herbicide fallow in the tree rows, the yield amounts to 41.7–42.7 t/ha with or without the anti-hail net. The apple-fruit weight under the net is lower by 1.4 % and it does not depend much on the inter-row management, but apples are larger under mulching of the around-trunk stripes. The output of the marketable fruit under the net is lower by 1.8-2.2 %, the marketability is higher by 4.7-10 % under black fallow in the around-trunk stripes.

Keywords

• yield capacity
• fruit mass
• output of the marketable produce
• retention of rows
• sidebands.