مجله تولید گیاهان زراعی
سال هفتم شماره 2 (تابستان 1393)

In this study، we aimed to determine the effects of halo-priming on yield and yield components of four wheat cultivars in a saline soil. A field study was conducted in factorial based on randomized complete block design (RCBD). Soil pH was 8/1 and electrical conductivity was 9 dS/m. Wheat cultivars (Falat، Ghods، Chamran and Shoori4) were primed with CaCl2 solutions (Control، 0، 50 and 100 mM). Plant length، spike length، kernel in spike، kernel weight، grain yield، biological yield and harvest index were affected by cultivars. The highest grain yield، plant length and harvest index were observed in Shoori4 and Ghods cultivars، and the lowest grain yield، spike length and kernel in spike were observed in Chamran cultivar. Kernel in spike was highest in Ghods cultivar، and highest kernel weight was observed in Shoori4 and Chamran cultivars. The results of this study indicated that halo-priming had different effects in different wheat cultivars. Priming with 0 mM CaCl2 (hydro-priming) increased germination rate of Chamran and Ghods cultivars significantly. Halo-priming significantly increased leaf area index (LAI)، crop growth rate (CGR) and net assimilation rate (NAR) of Chamran cultivar. Hydro-priming increased grain yield of Chamran cultivar، but decreased grain yield of shoori4 cultivar. Halo-priming with 100 mM CaCl2 decreased grain yield of Ghods cultivar. Among the investigated wheat cultivars، Chamran was received the highest positive effects of hydro-priming.

In order to evaluate the waterlogging stress effects on yield and yield components of rapeseed، a pot experiment was conducted at Gorgan University of Agricultural Sciences and Natural Resources during 2010-2011. The experiment design was completely randomized with factorial arrangement and three replications. Examined factors were developmental stage (seedling، stem elongation، flowering and grain filling) and duration of waterlogging stress (0، 3، 6 and 9 days). An exponential decay and linear models were fitted to quantify waterlogging stress on yield and yield components. Maximum slope of grain number reduction were recorded at the seedling stages (-1. 45 per day) while the lowest slope belonged to the number of seeds per pod in the grain filling stage (-0. 94 per days). Maximum slope of grain yield reduction (-1. 73 per day) observed in the flowering stage while the lowest was recorded at stem elongation (-0. 6 per day). Control plants had the highest yield (5. 1 g per plant) while imposing 9 days waterlogging either flowering or grain filling stages (0. 18 and 1. 4 g per plant، respectively) decreased the seed yield. Most proteins levels were in grain filling stages and 3 days of waterlogging (28. 7%) and lowest was in the flowering stage and 6 days of waterlogging (17. 7%). Also oil percentage ranged between 47. 5% in stem elongation and 6 days of waterlogging to 32. 1% at flowering stage and 6 days of waterlogging. Allayet analysis of data indicated that high direct and indirect effect of biologic yield was in plant yield in waterlogging stress.

Drought stress is one of the most important problems of agriculture and an important factor of plant product reduction. Application of absorbent materials can help usage of sporadic rain fall and cause more maintenance of water storage. In order to study the effect of super absorbent polymer، potassium sulfate and manure under drought condition and favorable irrigation on some traits of foxtail millet، a split plot experiment in a completely randomized block design in three replication was conducted in research field of Shahid Bahonar University of Kerman in 1391. Irrigation in three levels (50،75،100 % F. C) as main plot and super absorbent polymer (100 kg/hec)، potassium sulfate (200 kg/hec)، farmyard (25ton/hec) and no use of them was as sub plot. Leaf chlorophyll index، relative water content، ion leakage، reducing sugar، proline and forage yield were evaluated. Results showed that decrease in irrigation causes a significant decrease in relative water content and forage yield and increase in leaf chlorophyll index، ion leakage percent، proline and reducing sugar. The most average yield of relative water content and forage yield and the least ion leakage percent، reducing sugar and proline was due to super absorbent polymer. Accordind to results super absorbent polymer can lessen damage of drought stress. The most forage in presence of super absorbent polymer demonstrates effective role of it under drought stress.

For comparison the growth characteristics and quantitative and qualitative yield of two summer savory species (such as Satureja khuzestanica and S. rechingeri) in response to rainfed and irrigated conditions، an experiment was carried out on the basis of split-plot design in completely randomized block design with three replicates in north of Khuzestan during growing season of 2012-2013. Irrigation treatments (15 and 30 days interval and rainfed) as main-plot and species in two levels (Satureja khuzestanica and satureja rechingeri) as sub-plot was carried out. The characteristics measured were fresh and dry yield، leaf and flower yield، essential oil content، oil yield، leaf area index and plant height. Results of variance analysis of traits showed that the effect of irrigation treatments on all traits except essential oil content and plant height was significant. Mean comparison of traits showed that in rainfed cultivation and by increasing in irrigation intervals، fresh and dry yield، leaf and flower yield، oil yield and leaf area index of both summer savory species were decreased amount of 54، 44، 55، 53 and 37%، respectively compared to control (Irrigation interval of 15 days)، but the essential oil content was increased by 6 percent. Fresh yield (3/14t/ha)، dry yield (1/82 t/ha)، leaf and flower yield (1/08 t/ha) and leaf area index (0/43) of specie of khuzestanica were higher than rechingeri specie، but essential oil content (3/7%) and essential oil yield (33/86 kg/ha) of Satureja rechingeri were more than Satureja khuzestanica.

The objective of the present study was to assess the combined effects of drought stress and foliar application of zinc and manganese on seed quality of red bean (Naz variety) during the accelerated aging test. The experiment was carried out as split factorial in a randomized complete block design (RCBD) with three replications at the research farm of Shahrekord University during 2010-2011. Drought stress levels (irrigation after 50، 70 and 90 mm evaporation from class A evaporation pan) was used as the main plot factor، while factorial combination of zinc and manganese foliar application (0، 100، 200 and 0، 150، 300 g. ha-1 for zinc and manganese، respectively) were used as sub-plots. After harvesting the seeds and preparation of composite samples، seeds were evaluated through the accelerated aging tests with four replications. The results showed that drought stress didn’t have any significant effect on germination indices. Mn foliar application increased germination rate، seedling dry weight and vigor indices (I and II). In between، Mn foliar application at the rate of 150 g. ha-1 had the maximum effect on germination indices. Between Zn foliar application levels، maximum seedling length، dry weight and vigor indices (I and II) were obtained for application of 100 g Zn per hectare. Based on the results of this study، drought stress with application of low concentration of Zn and Mn improves seed quality during the accelerated aging test as well as the seed storage capabilities.

Wheat is one of the most important crops in the world that is constantly faced with the different biotic and abiotic stresses. Programmed cell death is one of the methods for coping with different stress which is stimulated by several factors. Because salicylic acid is involved in resistance to various stresses، to explore the effects of salicylic acid on programmed cell death، the effects of salicylic acid exogenous treatment examined on the Chamran and Falat cultivars to evaluation of biochemical aspects of plant defense system to transmit messages during the programmed cell death. So، the experiment was conducted in a completely randomized design with three replications. Experimental factors consisted of two Chamran and Falat cultivars، Salicylic acid treatment at concentrations of 0، 2. 5، 5 and 10 mM and sampling after 8 and 12 hours treatment. The results of this study showed that catalase and polyphenol oxidase activity decreased with increasing of salicylic acid concentration، however carbohydrate، total protein، peroxidase and superoxide dismutase activity increased. The results indicated، as regards، these metabolites are involved in programmed cell death، salicylic acid exogenous treatment could involve in the regulation of programmed cell death through the involvement of antioxidant enzymes activity and protein levels.

A trial study was set to assess the influence of the plant residue management in conjuction with application of different nitrogen sources on accumulation and translocation of wheat stem reserves، at the Agricultural Faculty of Shahid Chamran University of Ahvaz during 2011-2012. The experimental design was split plot at randomized completed block design arrangement. The main plot were different wheat residue management at three levels (residue moving، residue incorporated to the soil and burning) and the subplot were different nitrogen resources (control، 75 & 150 kg/ha urea، Supernitroplus biological fertilizer) SNBF and 75 kg/ha urea fertilizer+ SNBF. Plant characteristic such as main stem internode length، weight and specific weight of internodes and dry matter accumulation and translocation were measured to learn about their growth behavior under plant residue and nitrogen treatments. The result showed that the plant residues are able to inhibit the growth of the internode length in particular those in which developed at the lower internodes of the plant stem. While، various nitrogen application have been shown more striking in term of growth of internode length as compared to the plant residues treatment and the majority of internode lengths on the plants were able to develop maximum growth at the 150 kg/ha urea. Similar growth for the internode length were obtained at the75 kg/ha urea+ SNBF، except for the peduncle length. The present study reveales information that the lower internodes are capable of conserving the most remobilization (307 mg) while peduncle holding the least remobilization (95 mg).

In order to investigate the effective factors on the reduction of rain-fed wheat yield، an experiment in 45 fields was conducted in the township of Bandar-Gaz in 2012. In this research، all information such as crop management operations، seedbed preparation، cultivar، site preparation، seed sowing، weed combating، planting and harvesting issues، time of toxicant spraying، used seed rate were collected during a growing season by preparing questionnaire answered by farmers. In addition، at the end of the growing season، the actual yield harvested by farmers، were recorded. Among the various parameters، plant and raceme density، farmer experiment، planting and harvesting dates had significant effects on wheat yield. Farmers with higher experiment had lower yield and with delay in planting and harvesting، yield was reduce. Results showed، there was between actual yield mean (2236kg/ha) and attainable yield (5698 kg/ha)، 3462 kg/ha yield gap due: low plant density (15%)، lack of acceptance of new finding (10%)، late planting date (30%)، inappropriate cultivar N8019 compared with N8118 (21%)، non-use Topic and Geranestar herbicides (18%).

Compound of 5-aminolevulinic acid (5-ALA) has herbicide behavior in high concentration. While، it acts as growth regulator at low concentrations and causes resistance to various stresses incluing cold and salibity. Therefore the exogenous application of 5-aminolevulinic acid was investigated to induce cold stress tolerance in young soybean plants (Glycine max L.). The experiment was conducted as randomized complete block design at Tarbiat Modares University، with three replications in 2010-2011. 5-ALA was applied at different concentrations (0، 0. 3، 0. 6 and 0. 6 mM) by seed priming and foliar application at V4 stage methods. Two temperatures (T1=10، T2=25ºC) were added to the experiment as temperature treatments. After 5-ALA application، the plants were in V4 stage subjected to cold stress at 10 ± 0. 5°C for 72 h. Cold stress significantly decreased plant growth، relative water content، chlorophyll، photosynthesis and stomatal conductivity while increased electrolyte leakage and proline accumulation. 5-ALA at low concentration (0. 3 mM) protected plants against cold stress، enhancing plant height، shoot fresh and dry weight، chlorophyll content، photosynthesis، stomatal conductivity as well as relative water content. Superoxide dismutase and catalase activities also increased by application of 5-ALA especially under cold stress condition. In most cases،5- ALA applied by foliar application method was better than seed priming method. Results show that 5-ALA، which is considered as an endogenous plant growth regulator، could be used effectively to protect soybean plants from the damaging effects of cold stress without any adverse effect on the plant growth.

Optimal use of lands heavily relies on careful assessment of agro-ecological resources. The present study was aimed to zoning of suitable areas for of soybean cropping in Qaresoo basin of Golestan province by Geographical Information System (GIS) and Analytical Hierarchy Process (AHP). In this study، environmental components included: minimum، average، maximum temperatures، precipitation، slope، aspect، elevation and EC. At first، ecological requirements of soybean were identified from scientific resources and used to determine suitable areas cropping. The Analytical Hierarchy Process (AHP) was used to determine the weight of criteria. Finally، the maps were integrated and overlaid in GIS media and afterward the zoning of soybean was done. The results indicated that about 28071 hectares (45%) of the agricultural areas and 17. 2% of the total area of the Qaresoo basin had a high fitness for soybean cultivation. Available water recourses، lower slopes and south aspects، suitable temperature and also the desirable Electrical Conductivity were the reasons make these regions suitable for this zone. About 5537 hectares (9%) of the agricultural areas and 3. 4% of the total area of the Qaresoo basin were evaluated less as suitable for cultivation of soybean due to high salinity level.