Sulfur effects on sugar content, enzyme activity and seed yield of rapeseed (Brassica napus L.)

Abstract

A field experiment was conducted in a randomized complete block design with four sulfur levels, S0, S1, S2 and S3, including 0, 12, 24 and 36 kg ha-1 (respectively) along with 115 kg N ha-1, to evaluate the economic yield of the rapeseed variety (Hyola401) in Abandankash in the Central District of Sari County in Northern Iran. Parameters such as leaf nitrate reductase, root nitrate, leaf and root sugars, root peroxidase, leaf catalase, as well as seed yield were recorded. The results of the analysis of variance revealed that there were highly significant differences between characters for the majority of the traits such as leaf and root nitrate, leaf and root sugars, root peroxidase, leaf catalase, and seed yield. Due to significant positive correlations between root nitrate reductase and seed yield, increasing this enzyme in roots by sulfur application would have an accelerating effect on rapeseed seed yield. A highly significant positive correlation determined between leaf sugar content and seed yield (0.75**) indicated that increasing levels of sulfur had a direct effect on leaf sugar content, which had an accelerating effect on the weight of kernel yield. Sulfur application significantly increased seed yield compared to the control (S0 level), and it ranged from 2744 to 3215 kg ha-1 in S0 and S3.