Evaluation of quantitative and qualitative yield of maize (zea mays L.) in response to micronutrient spraying under water stress conditions

The corn (Zea mays L.) is one of the tropical cereals and one of the family of grasses (Gramineae) belongs to monocotyledonous plants. Corn is considered to be the most widely-used corn in the world, and it is in terms of production after wheat and rice. Corn is one of the strategic cultivars due to the high importance of human and livestock feed and has a high adaptability to temperate and tropical climatic zones (Normohamadi et al., 2010). Although water is the most composition the earth of the plant. One of the main causes of decline in crop yields around the world is water constraints and its lack of proper distribution during the growing season. In other words, for optimal water allocation in crop production, there should be an appropriate correlation between the amount of water used and the amount of production. Among the abiotic stresses in nature, water scarcity is the most important factor in reducing the growth and production of crops. Corn is susceptible to dryness at all stages of development, but the pollination stage has been introduced as the most sensitive plant growth stage to drought stress. Due to drought stress, the leaf area of the plant decreases more than the final leaf number and the biological function and its components decrease (Ma et al., 2012). This research was carried out in Ahwaz in 2016 with a longitude of 48 degrees and 40 minutes east and a latitude of 31 degrees and 20 minutes north with a height of 22.5 meters above sea level. This experiment was carried out as split split plots in a randomized complete block design with three replications. The treatments included irrigation stresses at three levels (60, 90 and 120) mm evaporation from class A evaporation pan in main plots and spraying of complete fertilizer in three levels (non-spraying, spraying two in a thousand and spraying five in a thousand) were in sub plots. The results showed that irrigation stress and micronutrient spraying had a significant effect on yield, kernels/ear, chlorophyll index, protein yield, percentage of iron and zinc. The results showed that the highest grain yield (575.85 g/m2) was obtained from 60 mm evaporation from the pan and the lowest (414.4 g/m2) from 120 mm evaporation from the pan. The main cause of grain yield reduction in drought stress treatments was the reduction in the number of seeds per ear. On the other hand, micronutrient spray application caused a significant increase in grain yield. The highest grain yield (562.51 g/m²) was obtained from 5% seedling application and the lowest grain yield (455.65 g/m2) was obtained from non-spraying (control). Also, the results showed that zinc and iron micronutrients played a positive role in grain yield and corn grain protein, especially in water deficit conditions (Ghotavi et al., 2011). Since in the field of crop production, the true value depends on the quality of the crop, this study found that the micronutrient spray application plays an important role in the growth of corn, and also, considering that the highest grain yield and protein yields quantitative and qualitative applications of zinc and iron fertilizers that are considered as micronutrient elements were obtained, it can be concluded that by using such fertilizers, we can provide the best conditions for obtaining the maximum yield and yield in corn. On the other hand, soluble micronutrient elements reduced the damage caused by stress on grain yield. Due to the restriction of iron and zinc intake in iron and zinc in arid and semi-arid soils, spraying of elements to increase the amount of micronutrient elements in the plant is a logical method of application of fertilizer. Therefore, in general, the results of this research can be argued that in order to achieve maximum quantitative and qualitative yield, corn plant cultivation with micronutrient foliar application of two liters per thousand is recommended in appropriate moisture conditions.