Zirņu šķirņu raža un proteīna saturs integrētajā audzēšanas sistēmā = Yield and protein content of pea varieties in an integrated growing system

Legumes are a valuable source of protein that can help meet the demand for plant-based proteins in human and animal nutrition. Peas are one of the most important legume crops in Europe and Latvia, and they are of increasing interest in the food industry. The aim of this study is to analyse how agroclimatic conditions affect the yield and protein content of pea varieties. In 2023 and 2024, the yield and protein content of 14 pea varieties grown in Latvia were analysed at the Priekuļi Research Centre of the Institute of Agroresources and Economics. At the end of April 2023, a pronounced moisture deficit during sowing continued until July, affecting the field germination and the further development of peas. In contrast, the sowing in 2024 took place under good moisture conditions. In both years of investigation, the precipitation amount was below the long-term average in May and June. Heavy rains were observed during the pea ripening phase at the end of July 2024. The average yield of pea varieties was 3.2 t ha ־¹ in 2024, higher than in 2023 (1.70 t ha ־¹). The most significant yield increase (over 2.0 t ha ־¹) in 2024, compared to 2023, was for the varieties: ‘Eso,’ ‘Manager,’ ‘Orchestra,’ ‘Respect’, and ‘Trendy.’ In contrast, the yield level of the varieties ‘Bruno,’ ‘Karpate,’ and ‘Saxon’ did not change in both years of the study, which could indicate the adaptability of these varieties to changing weather conditions. The average protein content in peas in both years of the study was similar, 24.6% in 2023 and 24.1% in 2024. The highest protein content was in the variety ‘Bruno’, 27.3%. Protein content above 24.0% was for the varieties: ‘Saxon,’ ‘Orchestra,’ ‘Eso,’ ‘Ingrid,’ ‘Trendy,’ ‘Bagoo,’ ‘Karacter’ and ‘Kidam.’ The most minor changes in protein content between years were for the varieties: ‘Bruno’, ‘Saxon’, ‘Bagoo’, ‘Trendy’, ‘Karacter’, and ‘Kidam’. The protein content in 2024 was significantly lower for the other varieties than in 2023. The study results showed that both environment and variety play a significant role in determining yield and protein content. However, the result depends on the ability of each variety to respond to changes in environmental conditions.