Dry Matter Accumulation and Partitioning as Affected by Thinning in a Non-Prolific Maize Hybrid

The objective of the present field experiment was to examine how plant density and enhanced source, i.e. thinning treatments, may affect grain yield and its components for a non-prolific maize hybrid, SC۷۰۴. The environment of the hybrid maize crop was changed at intervals over its life cycle by removing every other plant in rows equispaced at ۷۵ cm apart with a population of ۱۳.۳۴ plants m-۲. The plants were grown with no water or nutrient restrictions. Results showed that earlier thinning was associated with greater stem, leaf, shoot and ear dry weight accumulation, ear kernel weight (EKW) and kernel number per ear row (KNER). In this ways the greatest of these characteristics were obtained in thinning at sowing i.e. ۶.۶۷ plants m-۲ throughout. Delay in thinning until the ۱۲-leaf stage reduced stem dry weight and EKW significantly. Thinning at tasseling also resulted in significantly lower stem dry weight accumulation compared to thinning at sowing. At final harvest, the stem dry weight of plants thinned at tasseling was ۲۰.۴۷% (P<۰.۰۵) lower than those thinned at sowing. Similar effects were found upon delay in thinning until tasseling on leaf, shoot, and ear dry weight accumulation. Delay in thinning until the ۱۲-leaf stage or later, also reduced EKW significantly compared to plants thinned at sowing. This reduction was attributable to decreased KNER and ۱۰۰۰-kernel weight. According to these results, KNER and ۱۰۰۰-KW were found to be yield components sensitive to light environment.

کلیدواژه ها:

Dry matter partitioning ، maize ، thinning