Iranian Journal of Crop Sciences
Year:2020 | Volume:22 | Issue:1|Papers Count:7

This experiment was conducted to evaluate the effect of deficit irrigation on seed yield and its components of sunflower hybrids, and also identify tolerant hybrids. Twelve sunflower hybrids; Farrokh, Shams, Ghasem, Barzegar, G5 ×43, G6×43, Hysun25, Hysun36, Azargol, Sumbro, Euroflor and Sirena were evaluated under three irrigation treatments; normal irrigation (60 mm), mild drought stress (120 mm) and severe drought stress (180 mm) evaportation from Class A Pan, using split plot arrangements in randomized complete block design with three replications in Islamabad Gharb research station, Iran in 2012 and 2013 cropping seasons. Irrigation treatments were assigned to main plots, and sunflower hybrids were randomized in sub plots. Results of combined analysis of variance showed that irrigation treatments had significant effect on growth duration, stem diameter, head diameter, seed per head, 1000 seed weight and seed yield, but had no significanteffect on seed oil content. Sunflower hybrids were significantly difference for growth duration, 1000 seed weight and seed yield. Interaction effect sunflower hybrid×irrigation was not significant for any of measured traits. Mean comparison showed that seed yield of sunflower hybrids was more affected by irrigation treatments than other traits, as average seed yield in normal irrigation, mild drought stress and severe drought stress were 4470, 3637 and 2832 kg ha-1, respectively. Reduction in seed yield was due to cumulative reduction in yield components such as head diameter, seed per head and 1000 seed weight. Sunflower hybrids were also different for growth duration, plant height, non-filled seed, head diameter, seed per head and 1000 seed weight. Barzegar and Sumbro hybrids had the highest and lowest seed yield (4091 and 3362 kg. ha-1, respecrively) and the the highest seed oil content was obtaind in Hysun36 hybrid (45. 6%). The results showed that Barzegar hybrid had the higher seed yield in both full irrigation and deficit irrigation conditions, therefore it can be recommended to be grown under these conditions.

The objective of this experiment was to analyze genotype × environment (GE) interaction for grain yield of 20 durum wheat genotypes to identify the yield stability and adaptability of genotypes using GGE biplot method as well as some univariate stability statistics. The genotypes were evaluated in three rainfed stations of Sararood (Kermanshah), Maragheh and Shirvan, Iran under both rainfed and supplemental irrigation conditions in three cropping cycles from 2015 to 2018. Combined analysis of variance showed significant differences among the genotypes, environments and GE interaction effects. The environment effect was accounted for the 81. 9% followed by GE interaction for 5. 2% and genotype for 2. 1% of total sum ofsquare (TSS). The large size of the GE interaction variance relative to genotype, suggests the possible existence of sub-environmental groups and genotypes with high grain yield and specific adaptation. Mean grain yield of genotypes across all environments was 2649 kg. ha-1, and 2212 and 3303 kg. ha-1 under rainfed and supplemental irrigation conditions, respectively. The highest mean yield was observed for breeding line G15 (2622 kg. ha-1) under rainfed conditions, and G3 (3744 kg. ha-1) under supplemental irrigation conditions. The GGE biplot analysis could differentiate environments to sub-environmental groups with top yielding genotypes. According to GGE biplot, breeding lines G14, G15, G8, G16 and G11 were identified as ideal genotypes with high mean grain yield and yield stability performance. Based on stability parameters the high yielding breeding line G14 identified to have the most stable grain yiled. The environments belonged to Maragheh location with higher "discriminativeness and representativeness" ability was found as ideal location for evaluation of winter durum wheat germplasm. The results also showed genetic gains for high grain yield and yield stability for durum wheat breeding program under cold and temperate cold dryland conditions of Iran.

To study the variation of plant traits related to stress tolerance in tolerant and sensitive barley cultivars under salt stress conditions, an experiment was carried out as factorial arrangements in completely randomized design in Payame Noor University of Mahabad, Iran in 2018. Application of salinity stress of 250 mM of sodium chloride started from tillering stage, and leaf samples were taken at 0, 3, 6 and 9 days following application of salinity treatment. The results showed that salinity stress had adverse effect on morphological and physiological traits such as those traits involved in cell-water relation and photosynthetic traits of the plant. Salinity stress increased sodium ion concentration, but decreased potassium ion concentration, imbalanceed ionic concentrations and decreased K+: Na+ ratio in the cell. In addition, under salinity stress, electrolyte leakage, proline and glycine betaine concentrations were higher than non-stressed conditions. The results also showed that the highest significant decrease in traits was observed in the 9 days samples after the beginning of salinity stress. Overall, Afzal cultivar had better response to salinity stress. Analysis of proteome showed that seven protein spots were in common between the two barley cultivars. Mass spectrometry showed that most of the identified proteins were involved in antioxidant defense, and therefore, the most important common proteins in the two cultivars were involved in cellular homeostasis. In general, the lower expression of these common proteins in cv. Makouei (sensitive) compared to cv. Afzal (tolerant) resulted its lower performance under salinity stress.

To save water, get suitable establishment, shorten growth duration and increase grain yield of maize, this experiment was conducted as split plot factorial arrangement in randomized complete block design with three replications at Mahidshat research station (Kermanshah, Iran) in 2017 and 2018 growing season. Two planting dates (10th and 20th of July) were assigned to main plots, and a combination of planting methods including; direct seeding, hydroprimed seed and transplanting with two maize hybrids (KSC 704 and KSC 260) as factorial arrangement were randomized in sub plots. Resultsof combined analysis of variance showed that the effect of planting methods (direct seeding, hydroperimed seed and transplanting) was significant (P < 0. 01) on plant height and ear, number of days to silk emergence and tasseling, grain moisture content and cob percentage and (P < 0. 05) on number of grain per row. Grain yield in the first planting date (July 10) was 17% higher than the second planting date. Gain yield in transplanting (10466 kg. ha-1) and hydroprimed seed (10899 kg. ha-1) methods was higher than direct seeding (10300 kg. ha-1) by 2 and 6%, respectively. The highest grain yield of KSC 704 (12203. 3 kg. ha-1) and KSC260 (10276. 4 kg. ha-1) obtained in the first planting date. Grain yield in the first planting date in hydroprimed seed of KSC 704 and KSC 260 was 11789 kg. ha-1 and 10153 kg. ha-1, respectively. Transplanting method caused early maturity of maize hybrids by 12 days. In general, under water shortage condition KSC 260 hybrid and transplanting would be more suitable.

To evaluate the effects of tillage and planting systems on soil physical properties, grain yied and its components, and milling recovery of rice (cv. Hashemi), an experiment was conducted at Rice Research Institute of Iran in 2017 and 2018 cropping seasons-using split plot arrangements in randomized complete block design with three replications. The experimental factors were; tillage methods (main plots) at three levels (rotary tractor, power tiller conventional puddler and power tiller rotary puddler), planting methods (sub plots) in three levels (manual transplanting, mechanized transplanting and direct seeding). Results of combined analysis of variance showed that fall-cone penetration depth and bulk density were significantly affected by tillage methods. Maximum penetration depth of fall-cone (10. 86 cm) and minimum bulk density (0. 86 g. cm-3) were observed in tillage rotary tractor. Plant height (144. 01 cm) and number of tillers per m-2 (344 tillers. m-2) in direct seeding were significantly higher than mechanized and manual transplanting methods. Maximum harvest index (49. 29%) and pushing resistance (5. 73 N) in mechanized transplanting was significantly diffirent in comparison to manual transplanting and direct seeding. Maximum number of panicles. m-2 obtained in direct seeding (288 panicles. m-2) followed by mechanized transplanting (284 panicles. m-2) which were significantly diffirent from panicle number per unit area in manual transplanting (261 panicles. m-2). Effect of tillage methods, planting methods and their interaction on head rice, broken rice and milling recovery were not significant. It can be concluded that power tiller puddler, mechanized transplanting and direct seeding may improve grain yield components with maintaining the the soil physical properties.

To investigate the effect of yellow rust disease on some agronomic and physiological characteristics of bread wheat cultivars, two field experiments were conducted in Agricultural Research Station of Miandoab in West Azerbaijan, Iran, in 2013-2014 and 2014-2015 cropping seasons. Experimental treatments were arranged as factorial in randomized complete block design with three replications. Treatments included; non-sprayed and sprayed of Tilt fungicide with six winter and facultative bread wheat cultivars (Zarrin, Alvand, Pishgam, Oroum, Zareh and Mihan). Environmental conditions was inductive and yellow rust disease occured naturally in both cropping seasons. The results showed that Zarrin and Alvand cultivars had the highest disease infection (63% and 57%, respectively) in the non-sparyed treatment. However, Pishgam, Orum, Zareh and Mihan cultivars were resistant to yellow rust disease. Yellow rust decreased grain filling duration in sausceptible cultivars (Zarrin and Alvand) by 10 days. Leaf chlorophyll content of susceptible cultivars decreased in non-sprayed treatment from the milky to hard dough stage with a steepy slope. However, in the sprayed treatment leaf cholorophyll content decreased with slower rate. Yellow rust disease in non-sprayed treatment caused the highest proportion of reserved carbohydrtaes remobilization in Zarrin and Alvand by 30%, but 1000 grain weight loss in susceptible cultivars was about 26%. Despite of 29% increase in grain yield of susceptible cultivars in the sprayed treatment, the higher grain yield was obtained from resistant cultivars, Pishgham and Mihan (7877 and 7593 kg. ha-1, respectively). It can be concluded that integrated disease management by using resistant/ moderately resistant cultivars and fungicide application would be the best crop management practice to control yellow rust disease and reduce environmental pollution by application of less fungicide and reducing production costs.

Study of potential of alfalfa ecotypes in biomass partitioning and harvestable and non-harvestable parts as well as induction of summer dormancy under water scarcity can lead to develop adapted cultivars for sustainable farming system andto meet targets of the breeding program. Therefore, this experiment was conducted with 10 alfalfa ecotypes under four irrigation managements at Seed and Plant Improvement Institute (SPII), Karaj, Iran, during 2016-2018. The irrigation treatments included; full irrigation and irrigation withhold for 20, 40 and 60 days ر Under stress and on stress conditions, Nikshahri and Yazdi ecotypes had the highest regrowth rate, therefore, these two ecotypes as well as KFA6 ecotype with high stem number demonstrated the highest survival rate under induction of summer dormancy. The highest biomass belonged to normal irrigation with 17. 31 t. ha-1 while the maximum unharvestable part yield with 7. 02 t. ha-1was measured in irrigation withhold treatment for 40 days. Yazdi and KFA6 ecotypes showed the maximum total biomass (15. 71 and 15. 76 t. ha-1 respectively) among warm and cold region ecotypes with different fall dormancy scores and can be used as aprentsin alfalfa breeding programs. Regarding to biomass partitioning ratio, KFA17, KFA6 and Yazdi, which are landraces, had greater harvestable part to unharvestable part ratio with 1. 63, 1. 43 and 1. 40, respectively. Therefore, these landraces can be selected for forage production under different irrigation managements. As the leaf to stem ratio has the main role in forage quality, Baghdadi ecotype with leaf: stem ratio of 1. 29 had the highest forage quality among studied ecotypes. Baghdadi also maintained its high quality in all irrigation management treatments. In alfalfa breeding programs focused on improvement of forage and unharvestable yield for sustainable production in both optimum and stress environment conditions, Yazdi and KFA6 ecotypes seems to be suitable.