Özet:

This study was conducted to determine the effect of different nitrogen doses on maize-weeds competition and corn yield in Aydın province in 2021-2022. Within the scope of the study, control, different nitrogen doses (12, 24, 48 kg da-1) and growers’ fertilization (50 kg da-1 15:15:15 NPK as base fertilizer, 20 kg da-1 N with hoeing, 40 kg da-1 ammonium sulphate with first irrigation) applications were included. 1/2 of the nitrogen doses were given as base fertilizer, 1/4 with hoeing and 1/4 with the first irrigation by using urea (46% N). Weed density (number/m2) and coverage (%) were evaluated at three different periods (before hoeing, one month after irrigation, at harvest period); as wet and dry weights only at first and third evaluations. Some yield parameters were also determined for corn at harvest time. The results indicates that nitrogen applications affected the density and coverage area of common purslane (Portulaca oleracea L.) and jimsonweed (Datura stromonium L.) at different rates in different evaluation periods, but did not have a significant effect on barnyardgrass (Echniochloa crus-galli (L.) P. Beauv.) and Johnsongrass (Sorghum halepense L. Pers). No relationship was found between nitrogen doses and fresh and dry weights of weed species. Different nitrogen doses and growers’ fertilization significantly increased corn height, cob weight, length and diameter, number of rows per cob, number of grains in a row and thousand kernel weight, and the increase in yield in the applications compared to the control was 15.26%, 67.74%, 77.59% and 68.58%., respectively. In conclusion, nitrogen applications were found to have negligible contributions to weed development and corn competition after a single hoe, however it has been determined that the use of 24 kg/ha of nitrogen is recommended both in terms of corn yield and economically.