Yield response of forage oats (Avena sativa L.) to nitrogen fertilization Harvested at successive stages of maturety

Abstract

Oats, Avena sativa L. has recently gained importance as a winter forage crop. However,fewinformation exists on management practices of the crop in Saudi Arabia.Afield study was conducted to evaluate yield repose of forage oats. c.v. Cayuse. to nitrogen fertilization when haIVested at different stages of maturity. The experiment was conducted at the Agricultural Research and Experiment Station, King Saudi University. College of Agriculture, Derab. Located about 50 km south west Riyadh. Fresh yield, plant height number of leaves and leaf area per plant were measured at time of haIVest. Percentage dry matter and leaf-stem ratio were also determined. Plant height, percentage dry matter and dry matter production increased significantly as time of haIVest was delayed. Number of leaves per plant. leaf area per plant and leaf stem ratio decreased significantly as time of haIVest was delayed.Increased in rate of nitrogen fertilization from nil to 150 kg/ha significantly decreased percentage dry matter. Dry matter production increased significantly at a rate of 75 kg N/ha but decreased significantly as the rate was doubled. Plant height, number of leaves per plant, leaf area per plant and leaf-stem ration increased significantly In response to nitrogen fertilization. Differencesdue to time of halvest X nitrogen fertilization interaction were slgnlflcant in all measured parameters except percentage of dty matter and number of leaves per plant. The results indicated that the best dry matter production could be achieved when harvested at the early soft dough stage and a rate of 75 kg/ha nitrogen fertilization. However, management factors, Le. planting date, variety selection and irrigation requirement need to be considered in making recommendations to farmers In order to obtain maximum forage production.