Mohsen Saeidi; Mandana Ajand
Abstract
In this study the effects of source limitation on grain yield of twelve barley cultivars (‘Aras’,‘Jonub’,‘Reihan’,‘Zarjou’,‘Sararoud’,‘Sahra’,‘Fajr30’,‘Karoun’,‘Gorgan’,‘Makouei ’and ...
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In this study the effects of source limitation on grain yield of twelve barley cultivars (‘Aras’,‘Jonub’,‘Reihan’,‘Zarjou’,‘Sararoud’,‘Sahra’,‘Fajr30’,‘Karoun’,‘Gorgan’,‘Makouei ’and ‘Nosrat(’ under post anthesis water deficiency were studied. Source limitation treatments were included that control, removing of awn, leaves below flag leaf, flag leaf and spike photosynthesis. All source limitation treatments significantly reduced grain yield, 1000 grain weight and number of grains per spike. In non-water stress, the highest reduction of grain yield was seen in removing of leaves below flag leaf treatment (27.6%). In water deficiency, the highest and the lowest grain yield reduction were seen in removing of spike photosynthesis (32%) and removing of awn (18.1%). Flag leaf removing significantly increased photosynthesis rate in remaining leaves in non-water stress (28.8%) and water deficiency (10.8%). The evidence from this study suggests that under water deficiency after anthesis, spike photosynthesis is more important than the other current photosynthesis organs in grain yield formation in barley.
laleh Abaslu; SEYED ABDOLREZA KAZEMEINI; Mohsen Edalat; Ali Dadkhahi
Abstract
In order to evaluate the effects of drought stress and planting method on some physiological and biochemical characteristics of two chickpea cultivars (Cicer arietinum L.) an experiment was conducted at the research station of College of Agriculture, Shiraz University using a split factorial based on ...
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In order to evaluate the effects of drought stress and planting method on some physiological and biochemical characteristics of two chickpea cultivars (Cicer arietinum L.) an experiment was conducted at the research station of College of Agriculture, Shiraz University using a split factorial based on randomized complete block design in four replications. The main factor was stopping irrigation at different growth stages of chickpea (full irrigation=I1, flowering=I2 and two weeks after emergence =I3) and the sub-factor included a combination of pea varieties (Arman and Azad) and sowing methods (planting on ridges, furrow and basin), respectively. Results showed that under drought stress, leaf area index, stomatal conductance, photosynthetic rate, chlorophyll a and b and total chlorophyll content decreased while proline content increased. The cultivar Azad had higher than to Arman, leaf area index, stomatal conductance, photosynthesis rate and chlorophyll. The highest photosynthesis rate obtained under full irrigation treatment (16.09µmol m-2s-1) and it’s reduced to 25.79 and 14.23 percent under water stress in I3 and I2 treatments respectively. Based on these results, it can be concluded that the cultivar of Azad is suitable for this region and it is suggested to be planted on the ridge as has higher photosynthesis rate and lower stomatal conductance reduction leading to a higher yield.
Majid Jafaraghaei; Amir hooshang Jalali
Abstract
To investigate the effect of water treatment and plant density on yield and yield components of two cotton cultivar, a two-year experiment (2006-2007) was carried out in Esfahan Agricultural Research Center. The use of a split plot factorial based on complete block with four replications for study. Two ...
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To investigate the effect of water treatment and plant density on yield and yield components of two cotton cultivar, a two-year experiment (2006-2007) was carried out in Esfahan Agricultural Research Center. The use of a split plot factorial based on complete block with four replications for study. Two irrigation levels 135 (I1) and 180 (I2) mm of cumulative pan evaporation Class A, from flowering stage to the end of growth were assigned as main plots and treatment combination of two varieties of Mehr and Oltan of cotton and plant spacing 12, 15 and 18 cm (respectively, 120.95 and 80 thousand plants ha-1) were assigned made up as subplots. The results showed that both cultivars Mehr and Oltan in the density of 95 thousand plants per hectare in I1 irrigation treatments, respectively, with 2805 and 2745 kg ha-1 of yields produced the highest levels of yield compared to other treatments. In the I2 irrigation treatment and 95 thousand plants ha-1 density, Oltan cultivars producing 2119 kg ha-1, and had lowest yield compared to other treatments. In both cultivars in 95 thousand plants ha-1, between the two treatments of irrigation levels, no significant differences in terms of leaf dry weight. The results showed that irrigation after flowering phase until the end of growth, based on 135 mm evaporation basin A and the density of 95 thousand plants ha-1 can be proposed, for both cultivars studied.