Physiological limiting factors of yield in different varieties of wheat, Triticum aestivum L., by changing source - sink relationships

In order to determine the physiological limiting factors of yield in different varieties of wheat, Triticum aestivum L., an experiment was conducted as split plot in a randomized complete block design with three replications in research farm of Islamic Azad university, Saveh branch in 006-007. Two large grain, Mahdavi, and small grain, Falat, wheat varieties were the main factors and removing flag leaf blade, removing three upper leaves, thinning of 0 percent of plants, removing of flag leaf blade and thinning of 0 percent of plants, removing of three upper leaves and thinning of 0 percent of plants and a control were considered as sub factors. The analysis of data showed that thinning of 0 percent of plants increased grain dry matter significantly in both cultivars. Removal of leaves decreased grain dry matter in Mahdavi cultivar more than Falat. Results showed positive reaction of small grain cultivar than large grain one in case of source limitation.