The effect of slow-release nitrogen fertilizer applied in different doses and periods on dent corn (Zea mays L. var. indentata) yield and yield components

In this study, the effects of slow-release nitrogen fertilizer applied at different doses and periods on yield and yield components in dent corn were investigated. Attempt; Under Şanlıurfa second crop conditions, in the 2021 growing season, it was established in the field crops trial area of the Faculty of Agriculture, located in Harran University Osmanbey Campus, in a trial design of divided parcels with 3 repetitions. The main plots of the experiment were nitrogen doses, and the sub-plots were application periods. In the study using DKC 6092 dent corn variety, four different nitrogen (N) doses were used: 15 kg/da, 20 kg/da, 25 kg/da and 30 kg/da, and these doses were applied to the plants; It was applied in three different periods: all with sowing (AS), half with sowing (HS) + half when the plants were 40-45 cm (HTF), and all when the plants were 40-45 cm (ATF). With the planting, 8 kg/da of phosphorus fertilizer was also applied to the soil. The plots were planted in 5m and 4 rows, with 70 cm between rows, 20 cm across rows and 5-6 cm depth. The obtained data were analyzed by variance analysis using the JMP statistical package program, the difference between the means was determined according to the Duncan (5%) multiple comparison test. In the study; Plant height, first ear height, plant stem thickness, number of leaves, ear diameter, number of grains on the ear, grain weight per ear, thousand grain weight, ear length, bud ratio, harvest index, hectolitre weight, grain crude protein ratio and grain yield were examined. The highest plant height (20 kg/da N, HS+HTF) was 214.8 cm, first ear height (20 kg/da N, AS) was 73.7 cm, stem diameter (20 kg/da N, AS) was 22.23 mm, number of leaves (20 kg) /da N, AS) was 11 leaves/plant, ear diameter (25 kg/da N, HS+HTF) was 45.74 mm, ear length (20 kg/da N, AS) was 20.03 cm, number of grains on ear (25 kg/da N, HS+HTF) was 596 number/ear, grain weight of ear (25 kg/da N, ATF) was 208.03 g/ear, thousand grain weight (30 kg/da N, HS+HTF) was 323.33 g, harvest index (25 kg/da N, ATF) was %46.09, hectolitre weight (30 kg/da N, ATF) was 78.93 kg/hl, in grain crude protein rate (30 kg/da N , HS+HTF) was 9.56%. The highest grain yield (1270.77 kg/da) obtained from application of 25 kg/da N and HS+HTF.The values obtained from plant stem diameter, number of grains on ear, grain weight of ear, ear length, harvest index, hectolitre weight and grain yield were found to be statistically significant. As a result of the study, grain yield values were found to be statistically significant in terms of nitrogen dose, and it was determined that the application of 25 kg/da nitrogen dose provided the highest yield and the highest economic gain.