Effects of planting date and seed priming on partitioning coefficients, grain yield and yield components of wheat(Triticum aestivum)

In order to study the effects of planting date and seed priming on partitioning coefficients, grain yield and yield components of wheat, an experiment was conducted at the Jolg-e-Rokh (Torbat-e-Heidarieh) research station in 2011-12. This experiment was conducted in a split-plot layout based on randomized complete blocks design with three replications on Gascogen cultivar of wheat. Planting date in four levels ( i.e. 12 October, 27 October, 11 and 26 November) and seed priming in eight levels ( i.e. Seed starter, kelp, fulic acid, humic acid, kff, GA3, water and control) were in main plots and sub plots repectively. The results showed that delayed planting dates reduced length of development, Leaf area index, and total dry matter. Planting date had significant effect on leaf and stem partition coefficient, specific leaf area(SLA) and leaf area partition coefficient(LAPC). Delay in planting increased SLA(8%) and LAPC(63%) and reduced spike partion coefficient(68%). Results also showed that delayed planting date result in reducing height(26%), spike number per square meter(73%), thousand grain weight(11%), biological yield(79%) and grain yield(83%). Seed priming increased leaf area index and leaf dry matter in 5-leaf stage and stem dry matter and total dry matter in pollination stage. The positive effect of priming on plant growth, decreased with the progress of plant development but not positive significant effect on yield and yield components on maturity stage.