Samarqand davlat veterinariya meditsinasi, chorvachilik va biotexnologiyalar universiteti

A.Isashov
Chairman of scientific council awarding scientific degrees, doctor of agricultural sciences, professor
A.N.Jurayev
Scientific secretary of the scientific council a warding scientific degrees, PhD in agricultural sciences
K.S.Komiov
Chairman of the scientific seminar under the scientific council awarding scientific degrees, PhD in agricultural sciences, associate professor


INTRODUCTION (abstract of PhD dissertation)
The purpose of research is to establish the influence of different sowing methods and standing density on the growth, development, yield and quality of the fiber of the early ripe variety "Omad" in the conditions of old-grown typical sierozem soils of the Samarkand region.
The object of research Old-irrigated typical sierozem soils of the Samarkand region and the early ripe cotton variety "Omad", plant densit and norm of mineral fertilizers.
The scientific novelty of the research is as follows:
for the first time, under the conditions of old-irrigated typical sierozem soils of the Samarkand region, on the ridges prepared in autumn, the optimal standing density was developed for row and two-row sowing and the norms of mineral fertilizers, which provide a high and high-quality yield of the Omad cotton variety;
it has been proved that with two-line sowing with a theoretical sowing rate of 110-120 thousand plants/ha, on the ridges prepared in autumn, when sown in spring, the plant density increased from 3.6 thousand plants/ha to 4.1 thousand plants/ha , at a rate of 140-150 thousand bushes/ha from 29.6 to 29.8 thousand bushes/ha, at a rate of 150-160 thousand bushes/ha from 38.1 to 38.7 thousand bushes. / ha, at a rate of 170-180 thousand bushes/ha from 26.3 to 26.9 thousand bushes/ha compared with row sowing in spring on a flat surface;
It was found that the number of bolls on one bush decreases depending on the plant density. The number of bolls decreased by row sowing on a flat surface in spring with a fertilizer rate of N₂₀₀P₁₄₀K₁₀₀ kg/ha at a seeding rate of 140-150 thousand plants/ha by 0.4-1.0 units, at a seeding rate of 150-160 thousand bushes. / ha by 1.0-1.1 pcs., with two-row sowing in spring on a flat surface at a fertilizer rate of N₂₀₀P₁₄₀K₁₀₀ kg/ha with a density of 150-160 thousand bushes/ha compared with sowing in spring on ridges prepared in autumn by 0, 2-0.6 pieces, and with a density of 170-180 thousand bushes / ha by 0.5-0.7 pieces;
a significant effect of mineral fertilizers and plant density on the yield of cotton has been established. If the yield of cotton during row sowing in spring on ridges prepared in autumn with a density of standing 110-120 thousand bushes/ha at a rate of mineral fertilizers N₂₀₀P₁₄₀K₁₀₀ kg/ha was 36.8 c/ha, then the yield of cotton with two-line sowing with a density of standing 170- 180 thousand bushes/ha amounted to 40.8 centners/ha.