The article is devoted to the problem of phosphoric nutrition of rice on chestnut soils of the northernmost zone of rice cultivation in Russia. The paper reveals the role of water-soluble fractions of phosphorus, aluminosilicates, iron phosphates and calcium phosphates in the nutrition of rice plants during the growing season. The influence of the previous culture on the content and consumption of these fractions was established.

A comparative study of the activity of amylolytic enzymes of six varieties of spring barley grown in the Educational and experimental farm of the Azov-black sea engineering Institute in two different hydrothermal conditions of the year (moderate arid and arid). It was proposed to compare the activity of these enzymes in four microphenophases: dry grain, pecking, fork and sprout for a comparative mass evaluation of all varieties. Quantitative differences in micropenises, by grade and year of reproduction.

Abstracts. The productivity of plants depends on the weight of 1000 grains (M1000), the density of the productive stalk, the number of grains per ear, cultivation conditions, etc. The aim of the research was to comparatively evaluate M1000 in seeds differing in the morphology of the embryonic part, in varieties of durum winter wheat bred by the Agrarian Scientific Center “Donskoy”. The weight of 1000 grains were determined according to the State Standard 10842-89. The most productive and frequently encountered are the seeds with the main morphotypes 2, 3, 4, and 5, and the seeds with minor morphotypes 1a, 1, 6, and 7 make up 5%. An average positive relationship with M1000 of the entire heap of seeds was shown only for seeds of 2 main morphotypes - embryo morphotypes 2 (r = 0.45) and embryo morphotypes 5 (r = 0.42). Indicator M1000 embryo morphotypes 3 is not associated with M1000 of the whole seed heap, and all other embryo morphotypes for this trait have medium and strong negative correlation. Consequently, obtaining a fully formed grain in the dry spring and summer period is ensured by the stability of the filling of seeds of the main morphotypes 2 and 5.