THE EFFECT DIFFERENT ROW SPACINGS SEEDING RATES AND DROUGHT ON THE FORAGE YIELD AND RELATED TRAITS IN FORAGE PEA

This study was conducted to determine the effect of different row spacings (RS) and seeding rates (SR) on the forage yield and related traits of forage pea (Pisum sativum ssp. arvense L.). The field experiments of the research were established according to the Split Plots in Randomized Complete Block Design with three replications under the rainfed conditions of Bismil, district of Diyarbakır province, Turkey, during two consecutive growing seasons (2019-20 and 2020-21). In the experiments, four row spacings, placed in the main plots, and four seeding rates, placed in the sub-plots, were tested, thus sixteen combination treatments were studied. Due to the great climatic variation between the growing seasons, statistically highly significant (P < 0.01) differences were detected between the growing seasons in terms of all the investigated traits. And the means of the results determined in rainy growing season (2019-20) were found to be higher than those obtained in the dry growing season (2020-21) in terms of all of the investigated traits. Additionally, the means of the investigated traits changed among the row spacing and seeding rate treatments as follows; days to 50% flowering 137.3–144.0 days, natural plant height 53.33–81.00 cm, main stem height 74.50–148.80 cm, main stem numbers per plant 1.12–2.16 stems plant-1, main stem thickness 3.42–5.56 mm, fresh forage yield 10.15– 45.57 t ha1 and dry forage yield 2.65–9.87 t ha-1. By considering all the means of the investigated traits in the two growing seasons, the biplot analysis results revealed that the investigated traits were divided into three groups, and fresh forage and dry forage yield traits took part in the same group. In terms of the two forage yield traits, 20 cm row spacing and 100 seeds m-2 treatment was found as the best combination treatment. Hence, when forage yield of forage pea is targeted, that treatment should be preferred.