Comparison of the effect of common and nanoparticle chelates of iron and zinc on yield and its components in corn

 Despite the high importance of corn seeds in various uses like green cobs, baby cobs, sweet corn, and popcorn, the production of oil, starch, dextrose, and syrup, less than ten percent of corn grains consumed in the country is supplied through domestic production. Deficiencies in the absorbable form of iron (Fe) and zinc (Zn) exist in most agricultural lands worldwide. This deficiency severely reduces the quantity and quality of crop yields such as maize. Lack of micronutrients in most agricultural soils of arid and semi-arid regions, such as most farming regions of Iran, is due to low absorbable form of micronutrients, imbalance with NPK fertilizers, high pH and low percentage of organic matters in soil and high bicarbonate content in irrigation water. By eliminating the lack of micronutrients through foliar spraying, it is possible to increase the grain yield of agricultural plants. Therefore, this study aimed to investigate the effect of traditional and nanoparticle forms of iron and zinc on some single cross-600 popcorn agronomic traits. This research was conducted as a completely randomized block design with three replications in the research farm of Razi University, located in Kermanshah city at 1319 meters above sea level in the crop year 2019-2020. This research investigated popcorn (single cross 600) with maternal line K1533 and paternal line ZK4722AA. In each block, there are 13 foliar treatments, including traditional and nanoparticle forms of iron and zinc (zero, 4, and 8 g lit-1) and combined nanoparticle treatments of iron4 × zinc4, iron4 × zinc8, iron8 × zinc4, and iron8× zinc8. The foliar spraying treatments were applied twice at the beginning of vegetative growth and the beginning of flowering. The data were subjected to analysis of variance by SAS, and means Fisher’s Protected method (LSD 5%) was used for mean separation. The results showed that all fertilizer concentrations and fertilizer groups (traditional iron, nanoparticle iron, traditional zinc, nanoparticle zinc, and combined forms) caused a significant increase in grain yield, dry forage yield, harvest index, the number of cobs per plant, the number of seeds in cobs and the number of rows in cob compared to the control treatment. However, they had no significant effect on the weight of 1000 seeds. The highest increase in grain yield compared to the control treatment (3590 kg ha-1) was related to the two treatment groups of traditional iron and nanoparticle iron×nanoparticle zinc with 81%. The treatment of iron nanoparticle8×zinc nanoparticle4 caused the most significant increase in grain yield (132%) compared to the control treatment. The number of seeds per plant was affected by fertilizer treatments more than the trait of the 1000 seed weight. The 1000 seed weight is probably controlled under the influence of genetic factors. It seems that the foliar application of micronutrients by eliminating their deficiency and their nutritional effect probably increases the balance in the growth and regulation of plant development processes and ultimately causes a significant increase in grain yield. Different concentrations of iron and zinc nanoparticle fertilizers were significantly more effective in increasing grain yield than different concentrations of iron and zinc common fertilizers. This result may be due to the characteristics of shape, size, distribution, and nanoparticle fertilizers compared to common fertilizers. The significant increase in grain yield under the influence of foliar spraying treatments indicated a significant lack of absorbable forms of iron and zinc elements and their critical role in the formation of corn grain yield in similar areas (arid and semiarid regions). Nanoparticle forms of iron and zinc fertilizers increase grain yield more effectively than traditional forms.