ali naderi arefi; ali ahmadi; Manijeh Sabokdast
Abstract
This study was carried out to examine the effects of drought stress on cotton leaf characteristics and its yield during 2014. The experiment was conducted in greenhouse and field conditions at Garmsar agricultural research station. The experimental design was RCBD with 3 replications arranged in split ...
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This study was carried out to examine the effects of drought stress on cotton leaf characteristics and its yield during 2014. The experiment was conducted in greenhouse and field conditions at Garmsar agricultural research station. The experimental design was RCBD with 3 replications arranged in split plots. Main plots and subplots designated to water stress levels and genotypes, respectively. In greenhouse, water stress decreased RWC and Excised Leaf Water Loss (ELWL). RWC of genotypes No.221, Aria, Narabri, and Sepid was higher than the others. ELWL of Aria, K8801 and K8802 was more than other genotypes whichalso their RWC was higher. ELWL of Varamin and Sahel cultivars were the lowest. At field conditions, the effects of 9, 12, 18, 24 and 30 day irrigation intervals after first flower stage, on yields of these cultivars were studied. Nine days intervals increased the yield of Varamin, Khordad and K8801 but their difference was not statistically significant. At fourth and fifth irrigation intervals,the yield of all genotypes decreased. 18 days intervals lead to yield loss too, but, because of insignificant decrease and for efficient use of water, it can be recommended that after normal irrigation from planting to first flower, to irrigate of cotton at 18 day intervals. Extension of K8801 can reduce water use and may help to permanent production.
Mohammad Moradi Telavat; Zohreh Kazemi; Seyyed Ataollah Siadat
Abstract
A field experiment was carried out to study the yield and physiological responses of rapeseed (Brassica napus L.) to boron application and high temperature stress due to late planting, in Ramin Agriculture and Natural Resources University of Khuzestan at 2013-2014. The experimental design was a split ...
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A field experiment was carried out to study the yield and physiological responses of rapeseed (Brassica napus L.) to boron application and high temperature stress due to late planting, in Ramin Agriculture and Natural Resources University of Khuzestan at 2013-2014. The experimental design was a split plots design in RCBD with four replications. Planting dates (18 November, 3 December, 17 December and 30 December) were placed in main plots and boron application treatments (control, 10 kg B.ha-1 incorporated with soil, boron spraying at 8 leaf stage and budding stages) were placed in sub plots. Planting date had significant effect on relative water content (RWC), cell membrane stability, peroxidase enzyme activity, leaf area index (LAI), canopy’s temperature, grain yield and dry matter. In addition, boron application had significant effect on LAI, peroxidase enzyme activity and yield. Late planting caused to decrease the grain yield and dry matter related to increased canopy’s temperature at flowering stages. Delayed planting from 18 November to 30 December, result in decreased grain yield about 60.5 percent. Boron application incorporated with soil caused to increased grain yield about 23 percent in comparison to control. High temperature stress due to late planting caused to decreased RWC, cell membrane stability and LAI in flowering stage. Generally, highest grain yield (4579.7 kg.ha-1) was obtained from planting at 18 November and 10 kg boron.ha-1 incorporated with soil, and lowest grain yield was obtained from planting at 30 December and without boron application.