Response of corn to irrigation periods and spraying concentrations of the growth regulator brassinolide and its effect on some growth traits and yield

الملخص EN

A field experiment was conducted in Babylon province - the Nile Test Station, located east of Hilla city, during the autumn season 2021.

In a sandy clay soil mixture, in order to know the effect of irrigation periods and spraying concentrations of the growth regulator brassinolide in order to improve the growth efficiency and yield of yellow maize, Baghdad 3 cultivar .The Randomized Completely Block design(RCBD)was used in a split-plot arrangement with three replicates.

The experiment included studying the effect of three periods of irrigation 6, 8 and 10 days and spraying the growth regulator brassinolide at a concentration of 0, 2, 4, 6 and 8 mg.

L-1 and their interaction in growth and yield of corn.

The results showed significantly excelled of the irrigation period every 6 days in the traits: the least number of days from planting to 50% female flowering, the highest plant height, leaf area, number of grains in cob, weight of 500 grains, and grain yield, which reached 52.20 days, 224.40 cm, 5958 cm 2 and 564 9 grain cob-1, 157.73 g and 8.93 tons ha-1 respectively, while the 10-day irrigation period achieved a significantly excelled in the percentage of protein in the grains amounted to 12.05%.

The spray concentration also 8 mg.L- 1 of brassinolide significantly excelled in the number of days to 50% flowering, leaf area, number of grains per cob and ear, weight of 500 grains, and grain yield, which amounted to 52.00 days and 6378 cm2 and 573.3 grains.cob-1 and 158.78 g and 8.63 tons ha- 1 The interactions showed a significant effect on the traits of vegetative growth, yield, its components, and quality.

The interaction treatment between the irrigation period of 6 days and spraying at a concentration of 8 mg L-1 gave the highest averages of vegetative growth, yield, and quality.