Abstract

In order to investigate Zn, Fe and Zn+Fe foliar application effects on soybean (Glycine max L.) yield and its components (number of pods per plant, number of seeds per pod and 1000 grain weight), a field experiment was conducted at Minodasht, Iran during 2009 and 2010 growth season. The experiment was arranged in split plot of a randomized complete block design and replicated three times. Parameters measured were grain yield, harvest index, first pod height, number of pods per plant, number of seeds per pod and 1000 grain weight. Results showed significant effect of Zn+Fe treatment on grain yield, number of pods per plant (p < 0.05) and 1000 grain weight (p < 0.01). The time of foliar application on number of pods per plant (p < 0.05) and 1000 grain weight (p < 0.01) was also significant. In general, the highest yield was produced by Zn+Fe combination treatment. There was a significant and positive correlation between grain yield and its components. Leaf area index in 407 growth degree days at the beginning of pod set (6/6), crop growth rate in 272 growth degree day (GDD) at the beginning of flowering (39/52) and net assimilation rate in 272 GDD at 10-leaf stage (3 g plant^-1 GDD^-1) reached the highest point, respectively.

Key words: Glycine max L., nutrients, seed production, growth indexes.