Showing 3 results for Relative Water Content
F. Bahadori, K. Arzani,
Volume 12, Issue 45 (10-2008)
Abstract
Control of tree size is one of the main problems for which techniques to reduce vegetative growth and increase fruit quality and yield are important in the orchard management system. With this aim in mind, mature peach trees of the cultivars J. H. Hale and Red Skin grown on peach seedling at the Moghan agro industrial orchard were used. The effect of paclobutrazol soil treatments, (0,0.5 and 1.5 gr/tree) on experimental trees during the dormant periods in the 1996-97 was evaluated. The experiment was carried out in a split plot on the basis of completely randomized design with six replications. The effect of paclobutrazol on some vegetative growth and relative water content of leaves was studied. Results showed that paclobutrazol significantly reduced vegetative growth in the first year of application the total dry weight of pruning in treated trees was less than that of controls. The high level of paclobutrazol caused the most growth inhibition. On a commercial scale, paclobutrazol treatment would be able to give substantial benefits to peach growers by saving in pruning costs.
M Alimohamady, A Rezaee, A.m Mirmohamady Meybodi,
Volume 13, Issue 48 (7-2009)
Abstract
This study was conducted in Research Farm of Isfahan University of Technology to evaluate some of the agronomic and physiological traits and grain yield potentials of ten bread wheat cultivars using a split plot design with three replications. Main and sub plot consisted of optimum and stress moisture treatments (irrigation after 70±3 and 130±3 mm evaporation from class A pan) and wheat cultivars, respectively. The results of analysis of variance revealed significant effect of moisture treatments on all traits except 1000-grain weight, harvest index, specific leaf weight, assimilate redistribution and difference of peduncle weights at heading. Significant differences were found among genotypes in the stress condition except for chlorophyll b and chlorophyll a to b ratio. Significant differences were detected among genotypes in optimum moisture condition for all characters, except for chlorophyll b, chlorophyll a to b ratio, harvest index and assimilate redistribution. Grain yields in two moisture conditions had significant positive phenotypic and genetic correlations with harvest index, number of grain/spike, RWC, chlorophyll a and sum of chlorophylls a and b and had significant negative correlation with RWL. Significant positive correlation was observed between peduncle weight at heading stage and difference of peduncle weights at stages heading and maturity with grain yield and RWC in moisture stress condition. The results of path analysis for phenotypic correlation coefficients between grain yield and their corresponding traits in the regression model showed that in stress condition harvest index had the highest direct and positive effect on grain yield and in non stress condition chlorophyll a had the highest direct and positive effect on grain yield. Results of stepwise regression analysis in non stress condition revealed that chlorophyll a, plant height and harvest index explained more than 90% of grain yield variability. Based on stepwise regression analysis in non stress condition, RWL, harvest index and RWC explained 95% of grain yield variability.
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.
