Growth Characteristics and Seed Yield of Peanut (Arachis hypogea L.) as Affected by Topping Height and Application Methods of Zinc and Calcium Nano Chelates

Peanut is one of the most important legume crop and rich in oil and protein. Topping of peanuts is important for penetration of solar radiant into canopy, and mineral nutrients improve peanut seed yield. This experiment was carried out as split plot arrangements in randomized complete block design with three replications in research station of Guilan agricultural and natural resources research and education center, Rasht, Iran, in 2016 and 2017 cropping seasons. Experimental treatments included: no topping topping, of main stem at 10 and 20 centimeters height above the soil surface were assigned to main plots and 10 treatments: non application of nano chelate as check, soil application of Zn, Ca and Zn+Ca, foliar application of Zn, Ca and Zn+Ca nano chelates and integrated application methods of Zn, Ca and Zn+Ca nano chelates as sub plots. The results showed that the highest seed yield (2722 kgha-1), pod number per plant (24.47), 100-seed weight (82.19 g), biological yield (6540 kgha-1), harvest index (57.53 %) and seed Zn content (12.08 ppm) obtained in foliar application of Zn nano chelates and topping of main stem at 20 centimeters above the soil surface. The highest seed Ca content (35.86 ppm) was measured under foliar application of Ca nano chelates and toppin of main stem at 20 centimeters above the soil surface. It was concluded that the foliar application of Zn nano chelates and topping of the main stem at 20 centimeters enhanced seed yield due to photosynthetic capacity increment and increasing of solar radiation penetration into the canopy of peanut under Guilan climatic conditions.