Effects of foliar application zinc, boron and copper micronutrients on growth indices and quantitative and qualitative yield of sweet corn

In order to investigate the effects of foliar application of micronutrients, Zinc, Boron and Copper individually and in combination on some growth indicators and quantitative and qualitative yield of sweet corn   (Zea mays L. var. Samyra) this experiment was conducted to form of complete block design with three replications in research farm of the Faculty of Agricultural Sciences, University of Guilan Iran in Spring 2015. Foliar treatments was including: 1-control (spraying with water) 2-Zinc 3-Boron 4-Copper 5- Zinc + Born 6- Zinc + Copper 7- Boron + Copper 8- Zinc + Boron + Copper. The results showed that foliar application of micronutrients was effective in increasing crop growth rate, leaf area index and total dry weight and in all these traits combined three elements foliar micronutrient treatment was superior compared to the other treatments. The highest of the forage dry matter digestibility and crude protein 56.17 and 14.69 percent, respectively, were observed in combine’s three micronutrients foliar treatment. In this study, the highest dry forage yield and grain yield 2286.67 and 2194.53 kg ha-1 respectively, was obtained, and belongs the treatment where all three micronutrients was used. Minimum dry grain yield was obtained with the amount of 1467.6 kg ha-1 from the control. Increase amount in dry grain yield was 49 percent from control to combined three elements spray treatment. So it seems that foliar application of micronutrients, Zinc, boron and Copper is a useful approach for increasing sweet corn seed yield in conditions similar to this experiment.