Yield formation of pea (Pisum sativum L.) as influenced by economically valuable traits and weather conditions in the dry steppe zone of Northern Kazakhstan

Abstract

Background and Aim. The productivity of field pea (Pisum sativum L.) in the dry steppe zone of Northern Kazakhstan largely depends on weather conditions during the growing season, particularly water availability at critical stages of plant development. Studying the relationships between yield and its components is important for breeding environmentally adapted forms. The objective of this study was to determine the relationships between pea yield and agronomically valuable traits and to assess the dependence of yield on weather conditions.

Materials and Methods. Field experiments were conducted in 2024–2025 at the A.I. Barayev Scientific Production Center for Grain Farming LLP. A total of 37 pea accessions representing semi-leafless and leafy morphotypes were studied. The assessment included the main yield components: the number of pods and seeds per plant, seed weight per plant, and 1,000-seed weight. Yield was determined from the seed weight harvested from each experimental plot. Weather conditions were characterized using air temperature, precipitation, and the hydrothermal coefficient. Correlation analysis was used to evaluate the relationships among the studied traits.

Results. The 2024 growing season was characterized by high water availability, whereas drought occurred during flowering and pod formation in 2025, with the hydrothermal coefficient decreasing to 0.17. Accessions L-26/120 (353.0 g m⁻²) and L-64/83 (338.9 g m⁻²) produced the highest yields. Yield formation was most closely associated with the number of seeds per plant and seed weight per plant. Strong positive correlations were found among the yield components (r = 0.77–0.96).

Conclusion. Pea productivity in the dry steppe zone is determined by the combined effects of yield components and weather conditions.