Studying the Effects of Using Herbicides and Split of Nitrogen Fertilizer on Yield and Yield Components of D79-15 Wheat

ABSTRACT: In order to study the effects of using herbicide and split of Nitrogen fertilizer on yield and yield components of D79-15 wheat, an experiment was conducted in the form of split-plot in randomized complete block design with three replicates in Behbahan during the agronomic year of 2011-2012. In this experiment, the four main factors were including: Atlantisherbicide(H1), Topic and Granstarmixing of toxicants (H2) and not using herbicides (H3). And four different splits of Nitrogen fertilizer as secondary factors were: consumption of all fertilizers during the planting stage (N1), consumption of all fertilizers during the tillering stage (N2), ½ distribution of fertilizer during the planting stage - ½ distribution of fertilizer during the tillering stage (N3), 2/3 distribution of fertilizer during the tillering stage – 1/3 distribution of fertilizer during the stem elongation stage (N4). The results of this research indicated that among the treatments of herbicides, Atlantis herbicide had the maximum grain yield with an average of 823 grams per square meter, which is mainly due to the effect on number of spikes per square meter. In treatments of distribution of Nitrogen fertilizer, the maximum grain yield with 928 grams per square meter was in distribution treatment of 2/3 Nitrogen fertilizer during the tillering stage and 1/3 of the rest of fertilizer was devoted to stem elongation stage which with distribution treatment of ½ of fertilizer during the planting period and distribution of ½ of the rest of fertilizer during the tillering stage were placed in one statistical group. These two treatments also devoted the maximum number of spikes per square meter to themselves and also had the maximum number of grains per spike. According to 1000 grain weight, there was a significant difference between treatments of split of Nitrogen fertilizer.