Effect of Nano Zinc and Iron Chelates Ratios on Yield and Yield Components of Grain Maize (Zea mays L.) in Intercropping with Cowpea (Vigna unguiculata L.)

To investigate the effect of using nano-chelate zinc and iron ratios on yield and yield components of maize and cowpea seeds, a factorial experiment was conducted by using randomized completely block design with three replications in the south of Kerman, Iran, during 2018-2020. Experimental treatments consisted of five levels of mixed culture of corn and beans (100% beans, 75% beans + 25% corn, 50% beans + 50% corn, 25% beans + 75% corn, and 100% corn) and four levels of iron and zinc nanoclates combination (iron nanoclate, zinc nano-chelate, iron nano-chelate + nano-chelate zinc and control). Number of seeds per ear row, 1000-seed weight, seed yield and harvest index were measured. The results showed that the effect of planting ratios on number of seeds per ear, 1000-seed weight and harvest index were statistically significant at 1% and on grain yield at 5% level of probability while it was not significant on number of seeds per ear row and number of rows per ear. The highest number of seeds per ear (707.8), seed yield (12787 kg.ha-1) and 1000-seed weight of corn (253 g) were obtained from 25% bean + 75% corn crop ratio. The highest harvest index (52%) was obtained from pure culture. Simultaneous application of nano-chelate iron and zinc increased the quantitative and qualitative properties of corn. Intercopping of 25% cowpea + 75% corn with nano-chelate application produced the highest proein percent (22.3 %). The highest value of land equality ratio (total) (2.12) was obtained by using a mixed cultivation treatment of 75% bean + 25% corn and the lowest (1.57) by 25% of beans were +75% of corn and zinc combinations. Finally, the highest grain yield of 12,993 kg.ha-1 was obtained from a intercropping of 75% corn + 25% bean and application of iron and zinc.