The influence of sowing rate on the production and growth of wild oat (Avena fatua) in the depleted semi-arid rangelands of Jordan

Abstract

The objective of this work was to determine the proper sowing rate of wild oat (Avena fatua) in the depleted north-eastern semi-arid grasslands of Jordan. Wild oat seeding rates of 15, 30, 45 and 60 kg ha^−l were evaluated in field studies that were conducted over two years at Jordan University of Science and Technology Campus located 22 km to the east of Irbid, Jordan. Measurements recorded each year included plant height, number of tillers per plant, oven-dry forage mass and seed yield. Forage and seed production increased in response to increasing sowing rate. The highest production values were obtained at a sowing rate of 45 kg ha^−l Increasing sowing rate to 60 kg ha^−l reduced both forage and seed yield, indicating that the optimum seeding rate for wild oat is 45 kg ha⁻¹ Forage and seed yield had a cubic relationship with sowing rate, having R² values of 0.55 and 0.78, respectively. Tiller production showed a negative linear relationship with sowing rate (R² = 0.35).