Micrometeorological Changes Through Agronomic Management Influence the Productivity of Field Pea (Pisum sativum Var. arvense L.) in the Lower Gangetic Plains of South Asia

Abstract

The planting date, plant population, and variety are crucial factors that interact with the physical environment and hence, meticulously influence crop output and performance. To determine the impacts of planting time, spacing, and varietal effects on field pea crop phenology, growth and yield at the Indo-Gangetic plains, the present experiment was designed for three rabi seasons. The treatments included four sowing dates from the first week of November to mid-December, with 10-day intervals, as the main plots; two varieties, that is, VL-42 and Rachana,and two spacing treatments (S1: 30 cm × 10 cm and S2: 45 cm × 10 cm), were included as subsubplots. A gradual delay in field pea sowing from early November to mid-December resulted in a 27% reduction in grain yield and VL-42 (1256.2 kg ha−1) prominently outperformed Rachana by 26% in terms of grain yield (920.5 kg ha−1). Narrow-spaced field pea crops presented significantly greater grain yields (1136.5 kg ha−1) than did wider crops (1040.2 kg ha−1). Microclimatic interactions of the treatments led to differences in the performance of the treatments. The field pea variety, VL-42 accumulated relatively higher growing degree day (GDD) of 1883.4°C days and heliothermal unit (HTU) of 11,949.2°C day-h compared to Rachana variety’s 1694.2°C days and 10,475.8°C day-h, respectively. Variation in crop phenophase duration was also observed, as a delay in sowing leads to exposure to a relatively high thermal regime, significantly shortening the length of the growing period by nearly 10 days. Agroecological indices (i.e., GDD and HTU) are also affected by phenology resulting higher values in within mid-November sown field pea crop compared to crops sown in mid December. Closely spaced (30 cm × 10 cm) field pea plants performed better in terms of grain yield, typically because of the greater plant population. Micrometeorological studies have indicated that in mid-November, field pea plants that are exposed to approximately 20 to 25°C mean air temperatures during their growth stages perform best in this region. VL-42 was found to be more climate resilient than Rachana and hence, can be adapted in the lower Gangetic plains of India for better yield potential.