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.
Farshid Hassani; Ahmad Asgharzadeh; Mohammadreza Ardakani; Aidin Hamidi
Abstract
This research was conducted to study the effect of PGPR (Plant Growth Promoting Rhizobacteria) on mini-tuber yield and absorption of nutrients in the greenhouse ofSeed and Plant Certification and Registration Research Institute in 2012. Minituber derived from tissue culture of two potato cultivars (‘Agria’ ...
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This research was conducted to study the effect of PGPR (Plant Growth Promoting Rhizobacteria) on mini-tuber yield and absorption of nutrients in the greenhouse ofSeed and Plant Certification and Registration Research Institute in 2012. Minituber derived from tissue culture of two potato cultivars (‘Agria’ and ‘Sante’) which were inoculated with 116 and 173 strains of Pseudomonas and two species of Bacillus (B. megaterium and B. Subtilis) all along with control treatments as separately and in mixture with each other. A pot experiment was conducted using factorial based on randomized complete design with four replications. After tuber-filling stage nutrient elements percentage was assayed. After harvesting, minitubers were separated and total yield in standard size was determined. Inoculation of PGPRs had a significant effect on yield and nutrient elements. The rate of absorption of nutrients and minituber production of two varieties showed a significant difference. Mean Comparison of traits showed that dual inoculation of two types of bacterial treatments had the most influence on the absorption of nutrients as well as the number minituber in standard size compared to the control (non-inoculated).‘Sante’ cultivarproduced the highest number of minituber compared with cv. ‘Agria’.According to the results, dual and separate inoculation of potatoes with PGPR not only intensify the synergy effects through growth and developments of roots, but also increase the nutrients absorption which cause enhancement of the tuberization and yield.