رابطه بين كم آبياري - كشت نشايي در برنج رقم طارم محلي روي خسارت كرم ساقه خوار برنج و عملكرد محصول

The Relationship between Deficit Irrigation - Transplanting in Tarom- Mahali Cultivar on Damage Caused by Rice Stem Borer and Crop Yield

In order to investigate the relationship between deficit irrigation - transplanting in Tarom- Mahali cultivar on population density of rice stem borer and crop yield, an experiment was conducted as randomized complete block design with 7 treatments (various irrigation regimes) at 3 replications. Samplings were conducted after 2 weeks of transplanting, regurarly (every 15 days). In each sample, 5 hills in one plot were selected randomly and then infected and non-infected tillers were counted. The rate of rice plant infection was low at sampling and the difference was not significant before and after the first spraying; but infection before and after second spraying and also treatmentsʹ interaction were significant at 1% and 5%, respectively. Dead heart of plants was not different significantly in the studying years but this factor was significant between the treatments (different irrigation regimes) at 5%. Also there was not observed any significant difference between the treatments. The research indicated that plant infestation was rather increased with sampling in different growth stages but low infestation and data for ANOVA are related to: 1. Low population density of pest (C. suppressalis), 2. Delay in transplanting of rice, 3. Asynchronisation between pest and host plantʹs phenology at the first generation of the pest, 4. Small plot areas. Although in this research, irrigation regimes had not any effect on population density of Rice Stem Borer, but the study must be conducted in the field condition for alogic and recommendable conclousion.