The Effects of Foliar Application of Plant Hormones at Booting Stage on Wheat Yield Components

Abstract

The grain number is one of the important components in final harvested yield of wheat and it is closely related to number of florets initiation during stem elongation and number of survived florets before anthesis specially at booting stage. A split-plot experiment using a randomized complete block design with three blocks was used to study the effects of different plant growth regulators [3-Indoleacetic acid (IAA), 6-Benzyalaminopurine (6-BAP) and IAA × 6-BAP] compared with control on two wheat genotypes (Sivand and Pishtaz), at booting stage. This study was conducted at Campus of Agriculture and Natural Resources of Razi University during 2012- 2013. The results showed that there was not significant different between the genotypes for the yield and yield components of wheat. But the effects of hormones were significant on grain yield, number of grains per spike and harvest index. The application of IAA × 6-BAP had greatest effect on these traits. However, the interaction effect between the genotypes and hormones was not significant for traits. The number of grains per spike had a positive and significant correlation with the wheat grain yield. The increasing in the grain yield could be attributed to increasing of grain numbers per spike that had been earned by application of two growth hormones (IAA × 6-BAP) at booting stage.