The effect of time and method of planting on the establishment and forage yield of Onobrychis subnitensin dry land condition of Sanandaj

This study was aimed at investigating the effects of planting time and method on the establishment and production of Onobrychis subnitens (sainfoin) in rainfed conditions of Saral research station (365 mm annual rainfall) in Sanandaj (Kurdistan-Iran) during 2013 -2016. Two planting times (spring and fall) and methods (line sowing and seeding) were studied in a split-plot design based on the randomized complete block design in three replications. The results showed that in the third year of cultivation, the average percentage of plant establishment in the plot was 53%, the average canopy cover of the plot was 45.4%, and the average fresh and dry forage yield of the plot (8 m2) were 5268.5 (6585.6 kg ha-1) and 2831.5 g (3539.4 kg ha-1), respectively. Traits of plant establishment percentage, plant density, average canopy cover, dry and fresh forage yield showed a significant difference (p < /em>≤0.05) between fall and spring sowing; however, the difference between line sowing and seeding methods and the interaction effects of time and planting method was not significant for the traits studied. The forage yield showed a significant positive correlation with plant height, plant weight, main stem number per plant, plot green cover percentage, plant vigor rate, and dry to fresh weight ratio of forage (p≤0.01), and also a significant positive correlation with plant density in plot and average plant canopy diameter (p≤0.05). Based on the results of the regression of forage yield as an independent variable on other traits, the plant fresh weight, plant height, and established plants percentage in the plot showed the highest contributions in the forage yield. This result indicates the high and direct impact of these traits as the main components of forage yield. In general, considering the relative superiority of plant establishment percentage and average forage yield in fall planting and line sowing method compared to spring sowing and seeding method, as the final result, fall seeding of this species in Sanandaj and similar areas is recommended.