Effect of Boron Concentration on Growth and Grain Quality of Maize (Zea mays L.)

Abstract The field experiment was carried out during the spring 2023 season at the Experimental Research Station of the Department of Field Crops, Faculty of Agriculture, University of Tikrit. The station is situated at a latitude of approximately 34.616°N and a longitude of approximately 43.679°E east of the equator. Four varieties of maize (Zea mays L.) were sown in a Randomized Complete Block Design (RCBD) in a factorial scheme with 3 replications. The main split plots included five levels: concentrations of spraying with nano-and mineral boron (spraying with only distilled water, spraying with mineral boron at a concentration of (1 and 2) ml -1 , and spraying with nano-boron at a concentration of 1 and 2ml -1 , whereas the secondary plots included four varieties of Zea mays L. (namely, Al-Maha, Baghdad, Al-Fajr, and 5018). To find out the effect of concentrations of boron on the growth and quality of grains for varieties of Zea mays L. The experiment proved the superiority of spraying with the mineral boron element 2 mlL -1 in the qualities of the number of days of planting to 50% male flowering (staminate flowering), and the number of days of planting to 50% female flowering (pistillate flowering), plant height and leaf area. Spraying with nano boron 2 mlL -1 has surpassed in the content of chlorophyll and all attributes of grain quality except the percentage of ash. It is noted from the evaluation of the performance of the varieties that Al-Fajir variety exceeded in both qualities the number of days of planting to 50% male flowering and the number of days of planting to 50% female flowering. However, 5018 variety exceeded and gave the highest averages in the following qualities: leaf area and oil percentage in grains, reaching (63.42cm 2 ) and (5.96%) respectively. Whereas, Baghdad variety exceeded in terms of height, chlorophyll content, protein percentage and starch percentage in grains and gave averages of 2.13 cm, 42.92 SPAD (Soil Plant Analysis Development), (9.42%) and (33.85%) respectively. As for the interaction between the varieties and the proportions of boron spraying, the combination (spraying of mineral boron 2 mlL -1 and Baghdad variety) outperformed in the attributes of plant height, chlorophyll content and ash percentage, recording 2.35cm, 45.78 SPAD and (1.40%), respectively. Concerning leaf area, the mineral boron spray surpassed 2 ml -1 with 5018 and gave a value of 711.09cm 2 . These results enable maize growers to select and produce maize varieties with early male and female flowering with an increase in the attributes qualities of the crop.