Effect of Application Time of Nitrogen Fertilizer and Plant Density on Some Grain Yield Components of Sorghum in Damascus Governorate

Abstract

This study was carried out in Abi Jarash farm, Faculty of Agriculture, Damascus University, during the 2021 agricultural season, to study the response of the sorghum crop to three plant densities (50000, 66666,100000) plants.ha^1- and three different dates for adding nitrogen fertilizer (the full amount of nitrogen fertilizer upon germination, adding the half amount of nitrogen fertilizer at germination and the other half in the middle of vegetative growth, adding one-third of the amount of nitrogen fertilizer at germination and the second third in the mid of vegetative growth and the last third at flowering) depending on some formal and productive characteristics: plant height (cm), panicle weight (g), grain yield (kg.ha^1-), the yield from dry weight (t.ha^1-), harvest index (%). Results of the statistical analysis showed that there were significant differences in all the studied characteristics between plant density treatments, where cultivation by the maximum density (100 thousand) plants.ha^1- to obtain the highest plant height (244.2) cm and the highest grain yield (2248) kg.ha^1- and the highest yield of dry weight (68) t.ha^1- compared to low-density cultivation (50 thousand) plants.ha^1-, which excelled in the two characteristics of the weight of the panicle and the harvest index. The results also show that there are significant differences between the dates of adding the nitrogen fertilizer, as the addition of the nitrogen fertilizer in two and three batches led to obtaining the highest

weight of panicle, grain yield, and harvest index compared to adding the nitrogen fertilizer in one batch, while it did not affect the yield characteristic of dry weight, in addition, There were significant differences in the interaction between plant density factors and the timing of adding nitrogen fertilizer, as planting with the most density and adding nitrogen fertilizer in two batches led to obtaining the highest plant height and the highest yield of dry weight with no significant differences between them.