اثر تداوم زهکشی سطحی میانفصل بر عملکرد و اجزای عملکرد برنج رقم طارم هاشمی

Abstract
Proper water management in the paddy fields has an important role in the efficacy of other production inputs in rice cultivation. One of the important parts of paddy water management is mid-season drainage. This study was conducted aimed to evaluate the effect of mid-season surface drainage on yield and yield components of rice, Tarom-Hashemi cultivar. To achieve this, a field experiment in the form of randomized complete block was done with the six drainage duration treatments of 0, 5, 7, 9, 11, 13 days and three replications at Haraz Extension and Technology Development Center. Some plant characteristics such as plant height, number of tillers, panicle length, percentage of filled grains, harvest index, dry matter and yield were measured. Statistical analysis showed that the effect of mid-season surface drainage on dry matter was significant and there were no significant difference for other studied characteristics in compared with control treatment. The maximum yield (5675 kg ha-1) was gained in treatment of 5-day drainage duration. Increasing midseason drainage duration to 13-day caused in decreasing grain yield as 13% with compared to control treatment.