Study of nitrogen fertilizer and cycocel on FV/FM and dry matter mobilization to grain yield of wheat (Triticum aestivum L.)

Abstract

In order to study of effects of nitrogen fertilizer and cycocel on yield, yield component and dry matter mobilization of wheat (Triticum aestivum L.) a factorial experiment was conducted based on randomized complete block design with three replications during 2014. Treatments were included nitrogen rates in four levels (without nitrogen application as control (N0) and application 80 (N1), 160 (N2) and 240 (N3) kg ha-1 urea) and four cycocel levels (without cycocel as control (C0), application of 500 (C1), 1000 (C2), 1500 (C3) ppm). Results showed that cycocel application increased chlorophyll index, photochemical efficiency of PSII (Fv/Fm) and dry matter mobilization from shoots and stem. Application of nitrogen and cycocel reduced dry matter mobilization from shoots and stem, contribution of remobilization from shoots to grain and stem reserve contribution in grain yield. Application of nitrogen and cycocel as N3C3 had 58.5% and 46.26% more dry matter mobilization from shoots and stem in comparison with N3C0. The highest 1000-grain weight by 28.90 and 28.54 g, respectively, belonged to application of cycocel as C2 and C3 and the lowest 1000-grain weight by 26.93 g belonged to the C0. The highest grain yield (1.068 g per plant), number of grains per ear (37.36) and 1000-grain weight (28.77 g) were obtained in application of 240 kg ha-1 urea. It seems that the increase of Fv/Fm ratio due to current photosynthesis in plants that were grown under cycocel and nitrogen treatments decreased mobilization of dry matter and stem reserves to grain yield. Generally, it was concluded that nitrogen and cycocel can be as a proper tool for increasing wheat yield.