Testing and Evaluation of Rice Variety Samples in Nurseries in The Conditions of Karakalpakstan

Аннотация

This study presents a comprehensive and in-depth analysis of rice variety samples Д-53 (Д-82), Д-66 (Д- 154(4-12-2)) in a control nursery plot, providing evaluations and conducting competitive variety testing. Keywords: Rice, variety, selection, control nursery plot, vegetation. significantly. For Uzbekistan’s rapidly developing Introduction: Rice crop ranks first in the world in terms agricultural sector, the goal is to create export-oriented of yield and second after wheat in terms of long-grain rice varieties with valuable economic traits, consumption. It is the main food source for one-third of early maturity, and resistance to stress factors [1]. the world's population and, despite its origin in the tropics, is widely grown in temperate regions. With the D. Utambetov and G. Khojambergenov's experiments global population increasing every year and the indicate that seed germination rate and field amount of agricultural land decreasing, while labor emergence vary from 0.9 to 3.9 grains per m2 and 0.2- costs are rising, it is crucial to introduce innovations in 0.7%, respectively. Processing coefficients for rice agriculture, especially in rice cultivation, by creating varieties range from 1.32 to 1.42%. According to their new varieties adapted to local conditions. findings, the early maturing “Guliston” variety matures 4-7 days earlier than other varieties, yielding 2-9 kg/ha The Republic of Karakalpakstan is a leading region for more. With water savings, up to 4.5 thousand m3/ha of rice cultivation, with significant potential for large-scale water is achieved. The “Guliston” variety is proposed sowing. However, due to unfavorable soil and climatic for secondary sowing after winter wheat [2]. conditions, water supply issues, delayed irrigation timing, increasing droughts, and factors such as soil According to B.Abdullayev and U.Abillayev, the salinity and extreme heat days, there are various Karakalpakstan rice fields are located in a sharply obstacles limiting the expansion of rice cultivation. continental climate zone with saline desert soils in the These challenges are primarily linked to water supply. lower reaches of the Amudarya River. Most irrigated lands in northern Karakalpakstan suffer from strong to According to B.Abdullayev, U.Abillayev, S.Jalmenova, moderate chloride and sulfate salinity. These low- and D.Turdishev, the current requirements for rice fertility soils, saline due to shallow groundwater, are varieties in modern rice cultivation have changed American Journal Of Agriculture And Horticulture Innovations 37 https://theusajournals.com/index.php/ajahi American Journal Of Agriculture And Horticulture Innovations (ISSN: 2771-2559) unsuitable for cotton, wheat, and other crops, with a Rice” in Karakalpakstan. relatively short warm season in spring-autumn. Observations, measurements, and calculations were Complex natural stress factors, limited irrigation water, carried out according to the standard methods of and especially its late arrival significantly restrict the A.P.Smetanin [1972] and the Methodological Manual expansion of rice cultivation [3]. for Field Experiments [2007] [5]. The components of U.Abillayev emphasizes that in the extremely harsh soil yield indicators were analyzed in the laboratory, and and climatic conditions of Karakalpakstan, stress- the most productive, low-stemmed, early maturing tolerant varieties play a crucial role in achieving stable samples were selected. The data obtained were rice yields [4]. analyzed using the dispersion method of B.A.Dospexov. Given global climate change, the requirements for new RESULTS AND DISCUSSION varieties have become extremely complex, placing a Samples in the control nursery plot were sown in pairs heavy burden on breeders to consider numerous traits (standard) using the standard “Guliston” variety for and characteristics. comparison. The samples were analyzed for their The factors mentioned above present significant tillering ability (number of stems) during the seedling obstacles to rice cultivation in Karakalpakstan, which and full ripening phases. breeders must address. These challenges highlight the The ability of rice plants to produce tillers is a key factor need to develop new varieties well-adapted to local influencing growth and yield. The tillering ability of a harsh conditions and meet the global market’s demand variety reflects its biological adaptation to the local for high-yielding varieties. environment. We observed significant differences in Our research aims to identify promising high-yielding field emergence and survival until full maturity among rice variety samples with positive traits that are the varieties. adapted to local stress conditions by conducting Through agrobiological evaluation, we identified thorough evaluations and selecting the most suitable samples with many positive traits, as well as those that ones for use in breeding programs. are resistant to the stress factors of Karakalpakstan and ME