Abstract
In order to evaluate the effect of irrigation withholding and foliar potassium application on some physiological traits (photosynthesis, cell membrane stability and chlorophyll) and harvest index of wheat (Triticum aestivum L.), an experiment was carried out using a split plot factorial based on a randomized ...
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In order to evaluate the effect of irrigation withholding and foliar potassium application on some physiological traits (photosynthesis, cell membrane stability and chlorophyll) and harvest index of wheat (Triticum aestivum L.), an experiment was carried out using a split plot factorial based on a randomized complete blocks design with three replications in 2011-2012 in two locations: Seed and Plant Certification and Registration Research Institute, Karaj and Agricultural and Natural Resources Research Center, Yazd. The experimental factors were included drought stress (three levels of irrigation withholdings were irrigation withheld from ear emergence to physiological maturity, irrigation withheld from grain filling to physiological maturity, and normal irrigation) foliar potassium application (without potassium application, 1.5 and 3.0% K2SO4) and genotype (two wheat cultivars of ‘Marvdasht’, ‘Pishtaz’and aline‘WS-82-9’). Results showed that the studied characteristics were significantly reduced by increasing drought stress level. The highest harvest index was observed in ‘WS-82-9’ in Karaj under normal irrigation (32.69%) and the lowest harvest index was obtained from ‘Marvdasht’cultivarin Yazd, under severe stress (11.50%). Genotypes were different for cell membrane stability and the lowest rate was belonged to ‘Marvdasht’ (35.5%). Foliar application of 3.0% K2SO4 caused to significant differences in physiological characteristics, especially for leaf photosynthesis under severe drought stress condition: photosynthesis increased 99.1 and 69.7% in Yazd and Karaj, respectively. It can be concluded that cultivating of ‘WS-82-9’ and spraying of 3.0% K2SO4 were effective to moderate drought stress, especially when fields have limitations for irrigation water at the end of crop life cycle.
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.