PRODUCTIVITY AND ADAPTABILITY OF SPRING BREAD WHEAT (TRITICUM AESTIVUM L.) VARIETIES IN DIFFERENT AGRO-CLIMATIC ZONES OF KOSTANAY REGION

Abstract

The study presents the results of a comprehensive assessment of productivity and adaptability of six spring bread wheat (Triticum aestivum L.) varieties under contrasting agro-climatic conditions of Kostanay Region, Northern Kazakhstan. Field experiments were conducted during 2022- 2024 in two agro-climatic zones represented by Bannovka (ACZ-1) and Sadchikovka (ACZ-2) under two agronomic backgrounds: fallow and cereal stubble. The varieties Patricia, Granny, KWS Buran, Odintsovskaya, Inzhu and Aina were evaluated for grain yield and grain quality traits to determine their adaptive responses to environmental conditions. The results demonstrated that grain yield was significantly influenced by agro-climatic conditions, hydrothermal regime and predecessor type. The fallow background provided a yield advantage ranging from 11 to 21 c ha⁻¹ compared with cereal stubble. Significant varietal differences were identified in Agro-Climatic Zone 2 (p = 0.039), indicating differential genotype responses to environmental factors. The varieties Patricia, Granny and KWS Buran exhibited the highest productivity and adaptability under contrasting growing conditions. Grain quality traits were influenced primarily by weather conditions during the growing season rather than by varietal characteristics. The obtained results may be used to optimize varietal composition and develop adaptive cultivation technologies for spring bread wheat under increasing climatic aridization in Northern Kazakhstan.