Effects of gibberellic acid spraying at different nitrogen levels on the Super Wheat cultivar in two areas of Iran

The effects of gibberellic acid on different levels of nitrogen in high yielding hybrid cultivars of wheat can be effective in increasing the quality and quantity of grain yield. In this study, we investigated the effect of the spraying of gibberellic acid on the desired concentration in different levels of nitrogen on the quantity and quality of grain of the Super Wheat hybrid cultivar in the Karaj and Hamadan regions, according to the split plot experiment in a randomized complete block design with 4 replications. The main factor in this experiment included three different levels of nitrogen (60, 105 and 150 kg/ha) from urea sources; the second factor includes two levels of gibberellic acid (zero and 100 ppm) in two different climatic zones, Karaj and Hamadan. According to the results of the three effects of region, nitrogen and gibberellic acid on biological yield, grain yield, and plant height, the number of grains per spike, grain hardness, grain protein, and percentage of phosphorus, potash and zinc on grain with a 1% error were significant. The highest grain yield (14.23 ton/ha), zinc grain (42.93 mg/kg) to 150 kg/ha of nitrogen and gibberellic acid in Hamadan, respectively, and the highest biological yield (35.4 ton/ha) and (37.2 ton/ha) belonged to 150 kg/ha of nitrogen and gibberellic acid consumption in Hamadan, respectively. The highest grain potassium levels (11.69 g/kg) and (11.63 g/kg) were related to the treatment of 60 kg/ha nitrogen and gibberellic acid and the treatment of 150 kg of nitrogen and no gibberellic acid in Hamadan, respectively. The results showed that the use of gibberellic acid led to a decrease in nitrogen consumption, and the use of 100 mg/l of gibberellic acid reduced the consumption of nitrogen by 45 kg/ha, which reduced the cost of nitrogen and the environmental effects caused by the use of nitrogen.