Showing 2 results for Prd
N Nourmahnad, M Emamzadei, B Ghorbani, A.r Mohamdkhani,
Volume 13, Issue 50 (1-2010)
Abstract
Water scarcity causes production losses in arid and semi arid regions. In this condition, deficit irrigation is one of the most important methods to minimize effects of water shortage. This research was conducted to evaluate the effects of two kinds of irrigation management (deficit irrigation and partial rootzone drying technique) on some of physiological and phenological characteristics and water use efficiency of tomato. The experiment was carried out in a completely randomized design with five treatments and four replications. The treatments consisted of DI75 and DI50 (supplying 75% and 50% water requirement) applied to the whole root system, PRD75 and PRD50 (supplying 75% and 50% water requirement) which was applied to one side of the root system, and alternated in every irrigation, and FI treatment, which supplied 100% water requirement, and was considered as control. The results showed that the highest water use efficiency was observed in PRD75 (6.28 kg/m3) and the lowest in DI50 (1.98 kg/m3). Water use efficiency was reduced 67% in DI50 and increased 4.6% in PRD75, as compared with full irrigation. Furthermore, plant water state showed that relative water content was higher in PRD treatments than DI treatments. The analysis of variance indicated that there was a significant difference in leaf diameter stomata among treatments at 5% level .The higher level of water increased stomata diameter. The opening of stomata in FI and DI treatments was higher than PRD treatments. FI had the highest numbers of stomata per unit of leaf area and PRD50 had the lowest (10509.04 and 6904.4, respectively). There was no difference among treatments in phenological characteristics in terms of growing degree-day to fruit yield and growing-degree day to harvesting.
A. Mohammadkhani, M.r. Nouri Emamzadeh, A. Mirjalili,
Volume 17, Issue 66 (2-2014)
Abstract
Four partial root zone drying (FULL, 1PRD50, 2PRD50, 3PRD50) treatments were investigated on tomato characteristics and water use efficiency using completely randomized design with five replications. In the control treatment (Full irrigation), all water requirement of plant was met in the root area equally during the growing season. Roots in 1PRD50, 2PRD50 and 3PRD50 treatments were divided into two equal parts and each side of root was irrigated one, two and three times, respectively. Results showed that the highest (44.43 g) and lowest (24.57g) tomato mean weights were obtained at full irrigation and 3PRD50, respectively. Maximum of diameter (43.1 ml) and fruit number (46 No) was observed in the control and minimum of these traits (15.6 ml and 20 No, respectively) was observed in 3PRD50 treatment. There was a highly significant difference between fruit number in all treatments. Highest yield and marketable yield was obtained in the control and 1PRD50 treatment, respectively. The highest irrigation water use efficiency was obtained in 1PRD50 (48 percent more than the control) and the lowest value was in 3PRD50 (27 percent lower than the control). Based on results of this study, partial intermittent irrigation (1PRD50) is recommendable for tomato production.
