Javad Hasanpour; laleh dehghan; mansoureh khalatbari
Abstract
Objective: This study was carried out in order to evaluate the source and sink relationship in spring wheat and the limiting effect of each on grain yield under optimal and water stress conditions.Methods: The experiment was conducted as a split-plot layout in the form of a randomized complete block ...
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Objective: This study was carried out in order to evaluate the source and sink relationship in spring wheat and the limiting effect of each on grain yield under optimal and water stress conditions.Methods: The experiment was conducted as a split-plot layout in the form of a randomized complete block design with three replications in the Varamin Agricultural Research Center in 2018-2019. The main factor was the water stress treatment at three levels: optimal irrigation (50 mm from the evaporation pan, equivalent to 8250 m3), medium stress (80 mm evaporation from the pan equivalent, to 5130 m3) and severe stress (110 mm evaporation from the pan, equivalent to 4100 m3); and the sub-factor included source and sink constraints in four levels: without restriction, removal of upper half leaves, removal of lower half leaves, and removal of half of spike length.Results: Irrigation stress reduced grain yield by 23.4% and 32.1% for mild and severe stress levels, respectively. It also caused a significant increase in proline content. The percentage of grain protein increased to its highest level and an average of 12.3% under severe stress. Water deficit reduced the chlorophyll a and b concentrations. The effect of source or sink restriction treatment was significant on all traits except for the relative leaf water content and chlorophyll b concentration. Removal of lower half leaves caused a significant reduction in grain yield by 10.3% and the decrease was greater for the removal of upper half leaves and was equal to 18.3%. The most negative effect on yield occurred with the removal of half the length of the emerging spikes and was 34.2%.Conclusion: In the selection of high-yielding wheat cultivars, longer spikes and longer durability of the area of the upper leaves should be considered.
Javad Hasanpour; Kaveh Zargari; Behnam Zand; mojtaba kanani
Abstract
In order to study the effects of planting date and cultivar on yield, protein percentage and physiological growth indices of Mungbean an experiment was conducted in Agriculture and Natural Resource Research Center of Tehran province in 2011-12. Four mungbean [Vigna radiata (L.) Wilczek] cultivars (‘Parto’, ...
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In order to study the effects of planting date and cultivar on yield, protein percentage and physiological growth indices of Mungbean an experiment was conducted in Agriculture and Natural Resource Research Center of Tehran province in 2011-12. Four mungbean [Vigna radiata (L.) Wilczek] cultivars (‘Parto’, ‘Gohar’, ‘Mehr’ and a promising line ‘NM-94’) were sown at 3 dates with 30 days intervals starting from 21 April to 22 June to identify the suitable variety(s) and optimum sowing date for getting maximum yield of mungbean. The design was a split-plot replicated three times with sowing date as main plots and cultivar as sub-plots. Promising line ‘NM-94’ was ranked first in terms of seed yield (1797.4 kg ha-1) followed in order of ‘Gohar’ (1674.8 kg ha-1). The highest seed yield (1678.2 kg ha-1) was obtained from 22 June sowing date. Delayed sowing caused to decrease of growth period length from 92.9 (for 22 April) to 82.6 (for 22 June) that it resulted to a significant decrease of vegetative growth indices such as plant height and biological yield. The maximum LAI and CGR were obtained at a longer time and had more value for earlier sowing dates. The growth period length decreased for the last sowing date, but early entering to flowering stage increased grain filling portion from total growth period. Sowing date had not a significant effect on protein percentage, but this effect was significant for varieties. ‘NM-94’ line and 22 June were the best choices for south east region of Tehran province.