improving irrigation water productivity for rice varieties at esfahan region, iran

in order to improve irrigation water productivity (wp) at rice production, a field experiment was conducted at shahid fozveh research station (esfahan region) during 2001-2003. experiment was arranged in a split plot design (rcbd) with three replications. the treatments were: three levels of irrigation managements including i1: permanent flooding under 3.5cm water during growth period, i2:permanet flooding under 2.2cm water during growth period and i3: 0-1.5cm alternative wetting and drying (awd)) considered as main plots and eight advanced rice cultivars consisting geredeh mahali, zayandeh-rud, sazandegi, hasani, 67-97, 67-113, 67-47 and 67-72 as sub plots. the treatments were compared based on yield grain and water productivity for irrigation management and rice varieties. results showed that maximum wp obtained from awd irrigation management and zayandeh-rud rice variety, its amount was 9.1 kg.mm-1. at this treatment with 33.4 percent reduction of water use, only 11.1 percent decreased paddy grain yield. results showed that it is not necessary to maintain the rice field submerged in whole grouwth period.