Пахта селекцияси, уруғчилиги ва етиштириш агротехнологиялари илмий-тадқИҚот институти

Sh.N.Nurmatov
Chairman of the scientific council 
awarding scientific degrees, doctor of 
agricultural sciences, professor
F.M.Khasanova 
Scientific secretary of the scientific 
council awarding scientific degrees, 
(PhD) of agricultural sciences, professor 
J.Kh.Akhmedov 
Chairman of the academic seminar under 
the scientific council awarding scientific 
degrees, doctor of biological sciences, 
professor 

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INTRODUCTION (abstarct of PhD thesis) 
The aim of this research study. 
Selection of optimal predecessors, providing 
high yield of wheat and their influence on soil properties, by maintaining and 
increasing the fertility of typical sierozem soils of the north-eastern region of 
Kashkadarya region. 
The object of the study are
the cotton variety «Bukhoro-102», the maize 
hybrid «Uzbekistan 300 MB», the chickpea variety «K-95», the mungbean variety 
«Radost», spring rape variety «Regina», and the as main crop is the winter wheat 
variety «Tanya» in conditions typical sierozems of the foothill zone of the 
Yakkabag district of Kashkadarya region. 
The scientific novelty of the study is as follows: 
in the first conditions of typical sierozems of the foothill zone of the north-
eastern district of the Kashkadarya region, various plants-cotton, corn, feed 
chickpeas (first variety n-95 K), mungbean, spring rape (first variety Regina) were 
studied as precursors of winter wheat; 
the influence on the soil fertility of residues of the roots and juveniles of the 
selected precursors, their chemical composition; 
the conditions of the Kashkadarya region, the rapeseed plant were 
comparatively evaluated and the positive influence were determined as a precursor 
among the previous crops; 
the were determined that such precursors as cotton, corn, chickpeas, mung 
bean, and rape affect the formation of the root system of winter wheat in the arable 
layer.