FEATURES OF THE LEAF SURFACE FORMATION OF SPRING CROP IN THE CONDITIONS OF THE VIDDLE AMUR REGION
The aim if the research was to study the features of the leaf surface formation of spring crops in the agroecological conditions of the Middle Amur region. The objects of research were: spring oats cultivar Express, spring soft wheat cultivar Khabarovchanka, spring triticale cultivar Ukro. The features of the spring cereal crops leaf surface formation at the main stages of organogenesis were shown. Also, the maximal leaf surface area of plants during the earing-flowering periods was established. The uttermost area of trhe flag leaf was determined during the jointing period for oats and triticale, and during earing stage - for wheat. Under favorable conditions, up to 7 leaf layers were formed in oats, 5-6 layers - for triticale and wheat, however, under the influence of negative environmental factors, a significant decrease in leaf apparatus was observed. A high direct correlation (R=0.891-0.986) between the yield of spring cereal crops and the total leaf surface area of plants was established. The formation of leaf surface area of cereal crops strongly depended on the complex of agrometeorological conditions of the growing season: the temperature of the surface air layer, photosynthetically active radiation and moisture supply.