THE EFFECT OF MINERAL FERTILIZERS AND SOWING DATES ON THE YIELD AND QUALITY INDICES OF ZHAYDARI DEVZIRA RICE VARIETY
The issues of increasing yields, maintaining and improving the quality indices of the domestic rice varieties are of paramount importance for Kyrgyzstan. This paper discusses the impact of the sowing dates of the old released variety Zhaydari devzira and the optimal rates of mineral fertilizers on the duration of the stages of growth, development, ripening and yield and quality indices. It has been found that at all sowing dates the action of mineral fertilizers lasts from the tillering stage, that is, it speed it up (by 3-5 days). Stem elongation begins by 6-8 days earlier and it continues during the ear emergence only with early sowing dates (May, 01 and May, 10), and with late sowing dates (May, 20 and May, 30) the application of mineral fertilizers does not speed up the process, but on the contrary, it delays it in comparison with the variant without fertilizing. In the variant without fertilizing, the biological yield depending on the sowing dates is 471-484 g m2 or 4.71-4.84 t ha, and in the variant with the application of mineral fertilizers (N130P100K70 a.i.) is 594-617 g m2 or 5.94-6.17 t ha. The increase of rice yield due to the application of mineral fertilizers is 1.33 t ha. The most suitable sowing date is May, 10. The height of rice plants in the variant without fertilizing is 80-95 cm, and with mineral fertilizers (N130P100K70 a.i.) is 105-125 cm. The local variety Zhaydari devzira is grown in Kyrgyzstan; when grown without fertilizers, the protein content in rice is not lower than 11.5%; starch - 70.3%, and ash - 0.8%; with mineral fertilizers, the protein content in rice is increased to 11.8%, and starch - to 71.3%.