جستجوی مقالات مرتبط با کلیدواژه « تعداد دانه در طبق » در نشریات گروه « زراعت »

The shortage of oilseeds and the high volume of oil imports in Iran and the limitation of water resources for the many oilseeds production, showed the necessity of identifying species and varieties adapted to these stressful conditions and determining the most sensitive stages. Nowadays, safflower, due to drought resistance, is considered as a plant crop in the Iranian crop rotation. Therefore, whith respect to importance of water stress and selection of appropriate planting date in crop production, this research was conducted to investigate the effect of delay cropping and irrigation regime on assimilate remobilization, yield components and yield safflower.

In order to investigate the effect of delay cropping and irrigation regime on assimilate remobilization rate, yield components and yield of safflower , a field experiment was conducted as split factorial in a completely randomized block design with three replicates at Agriculture College and Natural Resources of Darab, Shiraz University, during 2018-2019 growing season. Experimental factors consisted of irrigation regimes in three levels included normal irrigation, Cutting of irrigation at flowering and Cutting of irrigation at seed filling, three planting dates (6 December, 26 December and 15 January) and two safflower cultivars (Goldasht and local Isfahan). In this research, dry matter remobilization, remobilization contribution and remobilization efficiency, yield components and yield of safflower were determined.

Results showed that the measured traits were affected by irrigation regime, planting date and cultivar, significantly. Cutting of irrigation at flowering reduced number of capitule per plant, number of seeds per capitule, 1000-seed weight and grain yield of safflower cultivars by 21.86%, 23.87%, 28.37% and 33.74%, respectively compared to normal irrigation. The amount of dry matter remobilization, remobilization contribution and remobilization efficiency in cutting of irrigation at flowering increased 30.44%, 37.81% and 25.37%, respectively compared to normal irrigation. Also, delayed third planting date (15 January) reduced dry matter remobilization (44.17%), remobilization contribution (22.72%), remobilization efficiency (17.88%), number of capitule per plant (%). 14.57, number of seeds per capitule (20.65%) and grain yield (13.31%).

Cutting of irrigation at flowering and seed filling treatments decreased 52.32% and 34.54% of grain yield in Isfahan local cultivar at second planting date (26 December) compared to the normal irrigation treatment, respectively,. However, seed yield in this treatment did not differ significantly with the treatment of cutting of irrigation at seed filling in planting date on 6 December in Isfahan and Goldasht cultivars which seems to be due to increased assimilate remobilization and remobilization efficiency in cutting of irrigation at seed filling compared to normal irrigation. Therefore, selection of optimum planting date (26 December) compared to early planting date (6 December) and early mature Goldasht cultivar by 12.91% higher yield can be an appropriate strategy to improve and increase safflower seed yield under late season water stress in semi-arid regions.

To evaluate response of seed yield, oil content and oil yield of eight safflower (Carthamus tinctorius L.) cultivars; Goldashat, Parnian, Padideh, Golmehr, Sofeh, Mexico 6, Faraman and Mexico 13 to saline irrigation water (5.5-6.0 ds m-1) using randomized complete block design with three replications in Zahak agricultural research station, Iran, in 2014 and 2015 cropping seasons. Combined analysis of variance showed that there was significant (P < 0.01) differences between safflower cultivars for all traits. The highest seed yield belonged to cv. Goldashat, cv. Parnian and Faraman with mean of 2753, 2407 and 2326 kg ha-1, respectively. The highest oil content belonged to cv. Faraman and cv. Mexico 13, respectively. The seeds no. head-1 (r = 0.64**), 1000 seed weight (r = 0.60**), and oil yield (r = 0.91**) had strong significant positive correlation with seed yield. Goldasht had the highest seed no. head-1, 1000 seeds weight and highest seed yield in comparison with other cultivars. Therefore, cv. Goldasht was identified as a suitable safflower cultivar for being grown under saline irrigation water conditions in Sistan region.

To study the effect of plant density on some morphological traits, oil percent, yield and yield components of sunflower cultivars, an experiment was conducted at Research Field of Birjand branch Islamic Azad University, Iran in 2009 as a split-plot experiment arranged on a randomized complete blocks design with three replication. In this research main plots were sunflower cultivar in four levels (Progres, Hisan 36, Zaria and Star) and sub-plots were plant density in three levels (5, 7.5 and 10 plants m-2). The results indicated that the effect of cultivar on morphological traits, yield and yield components and oil yield were significant. Also, all mentioned traits and oil percent were significantly affected by plant density with exception on leaf number per plant. Mean comparison also indicated that Progres cultivar was significantly superior for plant height, stem diameter, leaf number per plant, head diameter, 100- seed weight and harvest index as compared with other cultivars. Also, increased density from 5 to 10 plants m-2 increased plant height and yields of seed, biological and oil, 13.2, 49.5, 67.5 and 64.8 % respectively, but significantly decreased seed number per head, 100-seed weight and harvest index, 14.8, 12.8 and 8.6 %, respectively. Overall, it is recommended to use Progres cultivar with the density of 10 plantsm-2 for the cultivation of sunflower under the conditions of this study.

In order to study the effects of salinity stress and sowing method on yield, yield component and oil percentage in two spring safflower a field experiment was conducted at Research Station of College of Agriculture, Shiraz University. The experimental design was a split split plot based on Randomized Complete Block with three replications. Treatment were two cultivars (Goldasht and Isfahan 14) as main plot and four salinity levels (.4, 5.9, 7.3 and 9.1 dS m-1) as sub plot and two sowing method (furrow and ridges) as sub-sub plot. Results showed that with increasing salinity seed yield and its component (capitula number per plant, seed number per capitula, capitula weight per plant and 1000-seed weight) were significantly decreased. The highest seed yield (2265.43 Kg ha-1) obtained at. 4 dS m-1 level and the lowest seed yield (1559.19 Kg ha-1) achieved at 9.1dSm-1 salinity level. The cultivar Isfahan 14 as compared with Goldasht cultivar was found more salt tolerant and in all of levels of salinity has higher seed yield. With increasing salinity, oil percentage of two cultivars decreased but this reduction in Isfahan 14 by (22.7 percent) lower than Goldasht cultivar. Seed yield in furrow sowing was higher by (4.7 percent) than ridge sowing. It seems that the modification of sowing method and selection cultivar are two agents that can be used as a way of alleviating the adverse effect of salinity on growth and yield.

In order to evaluate the effect of water stress and plant density on growth and seed yield of safflower، a study was conducted during 2009 growing season at Agricultural College of Shiraz University. The experimental design was split plot based on Randomized Complete Block Design with three replications. The treatments were deficit irrigation (100، 75، and 50% of field capacity-FC) as main plot and safflower density cultivar Sina in four levels (5، 10، 15 and 20 cm plant spacing) as sub plot. Results indicated that by increased plant spacing، seed yield decreased significantly. Maximum (351. 03 g m-2) and minimum (222. 95 gm-2) seed yields were recorded at 5 and 20 cm plant spacing، respectively. With reduction of irrigation from 75 to 50% FC، seed yield was significantly reduced up to 63% (from 368. 83 to 134. 10 g m-2). Among yield components، number of head seeds number per head and seed weight were significantly decreased. Plant height and seed oil percentage was also significantly reduced as a result of water stress and reduction of plant density. It is concluded the optimal safflower seed yield can be achieved by applying 75%FC deficit irrigation and 10 cm plant spacing that were (33 plant m-2).

Iran is amongst dry and semi-dry regions of the world and enjoys several diverse climates. The recognition of traits related to growth, yield and adaptation of sunflower, especially in relation to drought stress can remarkably affect the development of planting area and its yield increase. To study the effect of water deficiency stress and foliar application of Zn on sunflower (Helianthus annuus L.) yield and some of its physiological traits, a split plot experiment based on randomized complete block design was conducted with three replications at the Islamic Azad University of Birjand in 2010. The main plot was irrigation regime with four levels including I1= without stress (according to the plant’s water demand), I2= interrupting irrigation 1 time during the vegetative growth stage, I3= interrupting irrigation 1 time during the reproductive stage, I4= interrupting irrigation during the vegetative and flowering stages and the sub plot was foliar application of zinc sulfate with three levels including Zn1= without foliar application, Zn2= 0.5% concentration of zinc sulfate (2 kg/ha zinc sulfate or 659 gr ha-1 of zinc element), Zn3= 1% concentration of zinc sulfate (4 kg/ha zinc sulfate or 1319 gr ha-1 of zinc element). Results indicated that irrigation ceasing significantly decreased the number of seed head, 1000- seed weight, seed yield and oil yield, while the oil percent was not affected. According to the results, applying drought stress during the vegetative and reproductive growth stages decreased seed yield and oil yield as much as 20% and 31% in comparison with the control, respectively. In addition, Zinc sulfate treatment with 1% concentration increased the 1000-seed weight, seed yield and oil percent in comparison with other treatments. In this study seed yield showed a significant reduction under the influence of drought stress. The treatment of complete irrigation (according to the plant’s water demand) resulted in higher yields than other irrigation treatments. The greatest seed yield was obtained by foliar application of Zn with 1% concentration. Moreover, the least oil yield was observed where irrigation was interrupt during the vegetative and reproductive growth stages. Overall, application of Zn under water deficit conditions could be employed as a good strategy for reducing the detrimental effects of drought stress on growth and yield characteristics of sunflower.

To investigate the effects of water deficit stress on some morphological traits of three sunflower cultivars, a split plot experiment based on randomized complete block design was conducted with three replications during 2007 growing season at Agricultural Research Station of Tabriz Azad University. Water deficit at five levels (50 as control, 100, 150, 200 and 250 mm from class A evaporation pan) was assigned to main- plots and three cultivars (Aramvirsky, Allstar and Euroflour) were considered as sub-plots. Results showed that seed yields produced under 100, 150, 200 and 250 mm evaporation from the pan were 78%, 65%, 50% and 43% of the control seed yield, respectively. Among the studied cultivars 'Armavirsky' produced greater yield than 'Allstar', but 'Euroflour' did not show significant differences with the two other cultivars. Increasing water deficit stress significantly decreased seed yield and oil percentage. The interaction effect between water deficit stress and cultivar was significant on percentage of unfilled grain and filled grain.