Predicting factors affecting on main component of wheat yield

The final status of grains in the individual phases of plant development is determined and different factors effect on growing season during and each of these cases in its critical period can have an impact on the number of final grain yield. This study was conducted to explain of relationship between factors affecting on wheat yield components. A factorial experiment in a randomized complete block design with four wheat cultivars (Beak cross of Roshan, Chamran, Pishtaz and Mahdavi) under four sowing dates (23 October, 16 November, 11 December and 5 January) and four replications in sabzevar Agricultural sciences Research during 2010-2011 and 2011-2012 were performance. Temperature, stem and leaf nitrogen and stem dry matter per–anthesis were the best influenced parameters on KNO. Considering results of correlation coefficients, kernel number per square meter appeared to have the best relation (r:0.88) with mean temperature of stem elongation to anthesis. Exponential function could be used to estimate kernel number per square meter with stem dry matter at anthesis. Minimum stem dry matter at anthesis was 156.7 gr.m-2. Fitted model 95% of kernel numbers and formed when stem dry mater is revealed that 730 gr.m-2. During growing season, availability of trained juice, temperature and day length are involved in the production of total dry matter and dry matter production is directly related to the grain number so, each of these cases in its critical period can have an impact on grain number and final grain yield.