نشریه پژوهشهای زراعی ایران
سال چهاردهم شماره 3 (پیاپی 43، پاییز 1395)

IntroductionMajor cultivated cotton regions of Iran are located in dry and semiarid climates, therefore water deficiency or drought stress is inseparable part of cotton production systems in these regions. So identification and introduction of drought tolerant cotton genotypes is crucial. showed that water stress decreased plant growth rate, leaf area and finally photosynthesis in cotton. In addition plant height reduction is a primary effect of water stress. According to results, net photosynthesis, stomatal conductance and transpiration decreased simultaneously with an increase in drought stress intensity.
Physiologic traits monitoring were notified as a proper gadget for selection and improvement of germplasm. Whereas investigation of many genotypes in field conditions under drought stress is difficult and it is not accurate enough, also good correlation has observed between the results of drought tolerance at seedling stage and field experiments, therefore this research has tried to evaluate some of the morphologic traits in cotton genotypes at seedling stage under drought stress and none stress conditions.
Materials and Methods22 cotton cultivars were grown under none water stress (field capacity) and drought stress conditions(-1MPa) using a factorial arrangement of treatments based on randomized completely design with three replications at College of Agriculture, Ferdowsi University of Mashhad in 2011. Then each genotype (10 seed) was sown at a pot (1.5 l-1). At two true leaf stages, pots were tinned to one seedling. Soil moisture content was kept up to two true leaf stages at field capacity and at the end of experiment, it was conserved about -1MPa using weight method.
The measured parameters were:Plant height, leaf area, dry weight of leaf, stem, root and whole plant and also decreasing percent of each parameter under stress in comparison with control in any genotype was determined at the end of experiment. Stomatal resistance and leaf temperature were measured with leaf porometer set (model Decagon Devices, Inc) on three leaf stage of cotton seedling. Relative water content (RWC) of leaf was also measured. Variance analysis, Comparison of trait means and correlation between traits were carried out using SAS and Excel and least significant difference (LSD).
Results and DiscussionInteraction between water deficiency stress and cotton cultivars were significant (P

IntroductionOat is an important crop which is cultivated in 9,679,190 hectares and produced as much as 22,504,708 ton worldwide (FAO. 2011). This crop is used mainly as forage cereal; however, it is also used for human consumption in the form of oatmeal and rolled oats because of high amounts of B and E vitamins (25). Regarding to calcareous soils of Kermanshah province (Iran) and the importance of iron and zinc functions in human societies and efforts to find out a way to solve the problems caused by their deficiencies, an experiment was performed to investigate the genetic diversity among oat genotypes in term of iron and zinc contents in grain and agronomical traits under complete irrigation and moisture stress conditions.
Materials and MethodsThe experiment was carried out with 33 oat genotypes (Table1) in a randomized blocks design with two replications under complete irrigation and terminal drought stress conditions at the Research Farm of Campus of Agriculture and Natural Resources of Razi University, Kermanshah during 2011-2012 cropping seasons. Oat genotypes collected from different countries of the world were obtained from South Australian Research and Development Institute (SARDI). Sowing was performed by hand at five row plots, 1.2 m length, and 0.20 m row spacing. Regarding the amount and distribution of rainfall (Figure 1), irrigation was carried out five and two times at complete irrigation and terminal moisture stress conditions, respectively. Terminal (end-season) moisture stress was imposed at flowering stage. The rainfall at the cropping year of the experiment was 308 mm. Chemical fertilizer, herbicide and pesticide were not used at both sites. Before planting, the soil samples were collected from 0-30 cm depth from different parts of the field, air dried, passed a 2 mm sieve, and different physiochemical characteristics (Table 2) such as pH, EC, organic matter, zinc and iron contents of the sampled soil were determined (Page et al., 1982). At full physiological maturity, two middle rows of each plot were harvested to determine agronomic traits, grain’s iron and zinc concentrations. Grain Fe and Zn concentrations were measured by Atomic Absorption Spectrometer.
Results and DiscussionThe stress intensity was calculated as much as 30.1% (Table 4). In complete irrigation condition, the average grain yield was 4951 kg/ha and “Wintaroo” (7163 kg/ha) performed better grain yield than others. In moisture stress condition, the average grain yield was 3485 kg/ha and “Quoll” (6491 kg/ha) showed better grain yield than others. The reported average grain yields were much higher than oat’s average grain yield in world which was 2325 kg/ha for 2011 (9).
Results showed that oat genotypes did not significantly differ in grain’s Fe and Zn concentrations in both conditions. But, the range of data for iron in oat grain was from 63.59 (Wandering) to 159.26 (ND873364) and from 57.94 (Preston) to 114.28 mg/kg (Mortlock) in complete irrigation and moisture stress conditions, respectively. This range for zinc in oat grain were from 30.07 (Wallaroo) to 52.71 (IA91098-2) and from 27.81 (Wallaroo) to 54.98 mg/kg (Mortlock) in complete irrigation and moisture stress conditions, respectively. The analysis of variance showed significant variation among genotypes for iron and zinc uptakes under moisture stress condition. Due to higher grain yield of “Quoll” under moisture stress condition and acceptable grain yield in complete irrigation condition, the highest amount of iron and zinc of grain per hectare was found in “Quoll” under both conditions. The comparison of traits between complete irrigation and moisture stress conditions indicated that stress reduced most of traits, although these reductions were not considerable for iron and zinc in oat grains. As these reductions varied among genotypes, therefore, it could be concluded that the reductions or even increases in iron and zinc concentrations due to moisture stress were highly genotypic dependent. The results of coefficient correlations indicated that there was a positive significant correlation between zinc and iron uptake which could be helpful in breeding programs. The positive correlations between the concentration of zinc and iron in grains were also reported in the previous studies (Cakmak et al., 2004; Welch and Graham, 2005).
ConclusionsAccording to the results of this research, it can be concluded that the ranges of variations in iron and zinc in oat genotypes were considerable and useful which can be applied in continuing breeding programs. Moreover, “Quoll” (south Australian cultivar) could be introduced as a cultivar with high grain yield, high grain iron and zinc per hectare under moisture stress condition in Kermanshah province (Iran).

IntroductionSafflower is native to Iran, and is cultivated for high adaptability, low water requirement, resistance to drought and useful unsaturated fatty acid (Ashri et al., 1977). Identification of effective agronomic traits and relationship between them are important aims under water stress conditions. Among these characters, grain yield is the most important trait that is genetically polygenic and its direct selection has not been effective to improve this character, while this selection method can be useful for yield components. Ashri et al., (1977) by using path analysis found that seed yield variation among safflower genotypes was mostly related to diversity in 1000-seed weight and number of heads per plant under limited moisture conditions. Therefore, this study aimed to identify hidden factors that form traits, their impact on seed yield and also recognition of yield components, which playthe greatest role in determining yield under different water stress conditions.
Materials and MethodsPresent research was arranged at Bu-Ali Sina University research farm during 2012. The experimental design was split plot based on randomized complete block design with three replications. The main plot was allocated to three levels of water stress including no irrigation (control), cutting irrigation from %50 flowering to ripening (flowering stress) and no irrigation from onset of seeding stage to ripening (seeding stress). Six safflower cultivars such as PI, local Ajabshir, Mec11, Faraman, local Zarghan 6 and Sina as the second factor were placed in subplots. Each plot contained of 5 rows with 5 meters length, 50 cm row spacing, 5 cm spacing on each row. At the end of the growing season, after removing marginal rows, plants were harvested at the extent of two square meters from three central rows of each plot. Then seed yield was determined in the scale of gram per square meter, and statistical analysis was performed using SAS and Minitab softwares, path analysis was also carried out using Path2 software, graphs were drawn with Excel software, and means compared by LSD test at the 5% level of probability.
Results and DiscussionThe results showed that correlation coefficient of seed yield with harvest index at three moisture regimes including non-stress, flowering stress and seeding stress were respectively, 0.42*,0.76**and 0.46**, and seed yield with 1000 seed weight were also 0.53**, 0.88** and 0.43** respectively. In general it can be concluded that at flowering and seeding water stress conditions, the correlation between seed yield and harvest index was greater than non-stress condition. Under flowering stress, 1000 seed weight was more affected by stress impacts and the consequence of this reduction decreased seed yield. Stepwise regression method was used to evaluate the effect of each trait on seed yield as dependent variable, and also to reduce the number of independent variables. Regression analysis of effective traits on grain yield showed that harvest index and biological yield under three water stress conditions entered into the regression model. Under non-stress condition number of capitule per plant, seed weight before harvest index and biological yield also entered into the regression model, while at flowering stress 1000 seed weight joined the model prior to harvest index and biological yield. Stepwise regression method, path analysis and correlation coefficient estimations were considered for different traits in spring safflower. Results showed that 1000-seed weight, number of seeds per plant, number of seeds per head and biological yield were suitable indicators that could genetically improve seed yield under water stress conditions (Golparvar and Ghasemi Pirbaluti, 2010). Results also indicated that biological yield (0.99) and harvest index (0.90) under non-stress condition, while 1000 seed weight (1.82) at flowering stress, and harvest index (1.60) at seeding stress condition had the highest direct effects on grain yield.
ConclusionsImprovement of traits that have the most direct effects on grain yield and the highest coefficient correlations with grain yield can be considered to increase safflower grain yield at each level of water stress treatments.

IntroductionNowadays oilseed crops are considered as the second most important sources of energy in the diet. In this regard, cultivation of oilseed crops such as safflower (Carthamus tinctorius L.) is important due to quality of oil seed and medicinal properties. Different planting dates leads to adaptation of vegetative and reproductive growth of plant to temperature, day-length and various solar radiations and as a result affects plant’s development phase and yield. With delayed planting date , temperature and day length increases and development phase will accelerate. In this condition the crop yield will reduce due to crop growth and developmental period will shorten.
Sulfur is an essential element for plant nutrition and its role is greater than Phosphorus. Using sulfur increases the heads per plant and grain yield. In order to investigate the effect of sulfur fertilizer under heat stress condition at the terminal growth stages and its role in reducing the negative effects of high temperature stress on safflower, this research was performed.
Materials and MethodsIn order to study effect of planting date and sulfur manure on yield components, nitrogen and oil percent in safflower, a field experiment was carried out in a randomized complete blocks design with three replications in as split plot arrangement at Ramin Agriculture and Natural Resources University of Khuzestan during 2013-2014. The experimental treatments consisted of four planting dates of 30 November, 21 December, 22 January and 1st February were randomly placed in main plots and four levels of sulfur of 0, 200, 400 and 600 kg ha-1 performed randomly in subplots, Sulfur fertilizer was corporated to soil one week before each planting date. Harvest was performed from the mid-May to early-June, during physiological maturity. To measure the yield on maturity time after the removal of margins, Safflower plants were harvested from one m2 unit area. Nitrogen percent was determined by Kjeltec Analyzer Unit device. Grain oil was measured by PORIM procedure and finally the oil yield was calculated by multiplying oil content and the grain yield. Data from the experiment was analyzed using SAS software and mean comparison was carried out using LSD test at the 5% of probability.
Results and DiscussionPlanting dates significantly affected grain number per head, biological yield, oil yield, grain yield, heads per plant and grain nitrogen. Sulfur fertilizer had a significant effect on grain number per head, oil yield, grain yield, heads per plant and grain nitrogen. There was a significant interaction between planting date and sulfur on grain yield, number of heads in plant and grain oil percentage. The late planting date resulted in plants exposed to high temperature and resulted in decreased safflower yield and yield components. Based on the results, the highest grain yield 4012.66 kg.ha-1 obtained in planting date 21 December. Late planting dates reduced grain yield to 50.28 percent. It was concluded that 200 kg.ha-1 sulfur increased grain yield through increasing the grain number per head and the number of heads in plant.
Delayed planting decreased growth period length and resulted in reduced yield and its components. But the application of sulfur fertilizer by increasing yield components can compensate the loss of yield. Sulfur is sub-structure of fatty acid metabolism enzymes in fatty acid and bond formation reactions for the production of oil and involved in fat acids. Planting date and sulfur application in appropriate form increased grain and oil yield. Shortening the growing season due to a delay in planting and plant distance from the right conditions for growth reduced the grain yield. These factors limited the plant grow in optimal conditions, disrupted synthesis of primary and secondary metabolites in plants and had a negative effect on seed oil percent.
ConclusionsDelay in planting date reduced, flowering, grain filling period, potential production and economic performance. Delay in planting date reduced yield, dry matter production and harvest index. Sulfur increased photosynthesis and affected the formation of protein and fatty acids, which increased oil and nitrogen percent and grain yield. The study showed that late planting date reduced seed yield and oil performance, but using the 200 kg.ha-1 of sulfur from organic granular sources increased yield and yield components.

IntroductionAbiotic stresses cause 71% reduction in crop yield around the world, from which 20% is related to salinity stress. The importance of sugarcane increases every day due to greater demand for sugar. Since sugarcane has mainly grown in arid and semi-arid regions, salinity is one of the main problems for this crop due to higher evaporation in these areas. Salicylic acid (SA) is classified as a phyto – hormone and belongs to a group of phenol compounds. Salicylic acid can improve plant tolerance to abiotic stresses. This research aimed at studying the effect of SA on the alleviating of salinity stress in sugarcane.
Materials and MethodsThe effects of salicylic acid on the growth and some physiological responses of sugarcane (Saccharum officinarum L. cv. CP69-1062) were studied under salt stress. The experiment design was a factorial of two factors, based on a randomized completely design with three replications. The experiment was conducted in a greenhouse at the Sugarcane Research and Training Institute of Khuzestan, Iran in 2012. Treatments evaluated in this study were three levels of salt stress, including (ECW

IntroductionSafflower (Carthamus tinctorius L.) is an important oilseed crop grown throughout the semiarid regions in many parts of the world. It has been cultivated for its oil and flowers and as a meal. Alkaline stress is caused by alkaline salts such as Na2CO3 or NaHCO3 in the soil. Alkaline stress, is widespread environmental constraint affecting crop productivity ,which can inhibit absorption of inorganic anions such as Cl–, NO3– and H2PO4–, greatly affect the selective absorption of K+Na, and break the ionic balance. However, under alkali stress, accumulation of compatible solutes, such as betaine, proline and soluble sugar into the vacuole are considered as the basic strategies for plant re-established cellular homeostasis. Some reports have clearly demonstrated that alkaline salts (NaHCO3 and Na2CO3) are more destructive to plants than neutral salts (NaCl and Na2SO4). Moreover, the salt-alkali stress can directly damage plant growth, alter the availability of nutrients and disrupt the balance of ions and mineral nutrition. The objective of this study was to investigate the effects of alkaline stress on growth and some physiological characteristics of safflower.
Materials and MethodsThis study was conducted in a greenhouse in Vali-e-Asr University of Rafsanjan as factorial arrangement in completely randomized design with three replications. Experimental factors included alkaline stress in 7 levels (0, 10, 20, 30 , 40, 50 and 60 mM) and two varieties of safflower (Sofeh and 411). Seeds were planted in pots filled with perlite and cocopite (1:1). The pots were irrigated with a nutrient solution with half strength Hoagland's solution. After the fourth true leaves appeared, alkaline stress in the pot was created by adding NaHCO3, to half strength Hoagland’s solution. Control plants were only irrigated with half strength Hoagland’s solution. Plants were harvested after 40 days of seed sowing. After forty days, shoot and root height, shoot and root dry weight, Fv/Fm, PI, proline, total carbohydrate, malondialdehyde content, cha, chb, total chlorophyll, cartonoied content, potassium, sodium content and sodium to potassium rate were measured.
Results and DiscussionResult showed that with increasing alkaline stress, decreased shoot and root height, shoot and root dry weight. A similar result had observed previously in sugar beet. Researches have indicated that plants respond to elevated NaHCO3 concentrations in soil or in growing medium solution with decreased shoot and root growth. This could be due to either HCO3− or Na. Many of the data test showed high pH as a key factor in limiting plant growth and development under alkaline conditions. 411 variety showed superiority compared to Sofeh cultivar in mentioned characteristics. Also, Fv/Fm and PI decreased under alkaline stress condition, whereas proline, total carbohydrate and malondialdehyde content increased. Also, the increases in proline and total carbohydrate content were reported in wheat under alkaline stress condition. Baghre and Roosta (2012) reported that Fv/Fm values and PI reduced under alkalinity stress.
In the present experiment, alkaline stress decreased cha, chb and total chlorophyll whereas it increased cartonoied content. Yang et al., (2009a) concluded that in alkalinity stress, the contents of Chl and Car in the barley plants decreased sharply with increased stress in comparison to salinity stress. They also stated that high pH might decrease contents of photosynthetic pigments. Potassium content decreased under alkaline stress condition whereas sodium and sodium to potassium rate increased. Also, Zhang and Chun-Sheng (2009) reported that with increasing alkaline stress, potassium content decreased in Lathyrus quinquenervius whereas, sodium content and sodium to potassium rate increase. In wheat stems, a decrease in potassium content and potassium to sodium rate and an increase in sodium content were also observed. A high-pH environment surrounding the roots can cause metal ions and phosphorus to precipitate, with loss of normal physiological functions of roots and destruction of root cell structure.
ConclusionsResult showed that alkaline stress decreased shoot and root height, shoot and root dry weight, whereas proline, total carbohydrate and malondialdehyde content increased. Also, with increasing alkaline stress Fv/Fm, PI, cha, chb, total chlorophyll and potassium content decreased whereas cartonoied content, sodium and sodium to potassium rate increased. 411 variety showed superiority compared to Sofeh cultivar in growth characteristics, cha, total chlorophyll. Also, both cultivars showed same reaction under alkaline stress.

IntroductionSalinity is an important abiotic stress that reduces the crop production potential and the efficiency of plants in arid and semi-arid regions. Soil salinity can be increased by irrigation, inappropriate drainage, sea advancement to coastal regions and the accumulation of salts in desert and semi-desert regions. Salinity is a limiting factor for plant growth because it limits the feeding of the plants through reducing the uptake of P, K, nitrate and Ca and increasing inter-cellular ion concentration and osmotic stress. In addition to its adverse impacts on the yield and yield components of crops, salinity affects most processes involved in the growth and development of the plants too.
Materials and MethodsThe present study was conducted in research greenhouse of Department of Agriculture, Birjand University in 2013 on the basis of a Randomized Complete Block Design with four replications. The soil salinity treatments included five levels of 1, 3, 5, 7 and 9 dSm-1. Soil texture was loam-sandy with the pH of 8.09 and EC of 1 dS m-1. The irrigation water was filtered with EC Results and DiscussionIt was found that salinity level significantly influenced all measured traits. Salinity slightly increased SPAD index and adversely affected leaf relative water content (RWC), electrolytes leakage and grain yield, so that the highest level of salinity resulted in 17.7% lower RWC, 27.7% higher electrolytes leakage, and 59.8% lower grain yield per plant. Under salinity stress, plants reduce their leaf area to counteract the stress resulting in greater thickness of the leaves, the accumulation of more chloroplast per unit leaf area and the increase in leaf chlorophyll content. As a result, the leaves turn darker and SPAD index increases. Leaf relative water content is one of the photosynthesis-related indices in crops with is closely related to the yield. Membrane stability is a physiological trait that is influenced by environmental stresses. Higher accumulation of hydrogen peroxide and lipid peroxides due to salinity reduces membrane stability. Salinity stress causes the production of active oxygen species which is followed with the leakage of cellular membrane. One effect of salinity is on grain yield through changing 1000-grain weight. Lower 1000-grain weight can be associated with shorter grain filling period in salinity treatments and also with lower synthesis of assimilates. On the other hand, the changes in the pathway of assimilate partitioning to roots for counteracting the salinity can be another reason for lower dry weight of the grains. As well, salinity enhanced the activities of antioxidant enzymes in peas. It was revealed that the increase in salinity level from 1 to 7 dS m-1 increased the activity of enzyme catalase (CAT) by 63.79% and further increase to 9 dS m-1 resulted in the loss of its activity. The activity of enzyme superoxide dismutase (SOD) increased up to the salinity of 5 dS m-1 (by 57.22%), did not change up to 7 dS m-1 and decreased at 9 dS m-1. The highest salinity levels as compared to control increased the activity of enzyme ascorbate peroxidase (APX). The highest effects of salinity on the measured traits of peas were observed at the level of 7 dS m-1. As the first defense line, superoxide dismutase converts superoxide to hydrogen peroxide. This enzyme is capable of converting superoxide ions into oxygen and hydrogen peroxide and is active in Glyoxylate cycle. The detoxification of hydrogen superoxide is complemented with ascorbate peroxidase, thioredoxin peroxidase, glutathione peroxidase and catalase. Ascrobate peroxidase is an important enzymetic antioxidant in plants whose function is to detoxify H2O2 with ascorbic acid.
ConclusionsIn total, the examination of the effect of different levels of salinity on the measured traits showed that salinity did not significantly affect SPAD index of peas. It had negative impacts on physiological traits and reduced grain yield. In addition, it increased the activity of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) as salinity was intensified. A look at the status of the activities of antioxidants revealed that they were increased with salinity. It seems that this increase played a role in counteracting the adverse effects of salinity so that their decrease deteriorates the effects of salinity stress of plants. In total, the application of these levels of salinity indicated that peas are moderately sensitive plants to salinity, particularly salinity stress level of >7 dS m-1.

IntroductionBetween oil seeds, from the quality, quantity and nutrition index point of view, canola has the top level . Because of the solubility of N fertilizers, the time of urea application, is very important and one of the main reasons of the reduction in N application efficiency is utilization of urea in an inappropriate time. By precisely foliar application of nitrogen, the efficiency of nitrogen transformation to the grain will be very high because in this method the leaf is considered the main organ of nitrogen uptake and a low amount of absorbed nitrogen was transferred to the root and entered the soil. The more division of N application in growth stages and in accordance with plant need and foliar application result in increasing nitrogen use efficiency. The delay in sowing will result in the reduction of yield and this is due to low LAI, and thus low radiation absorb in vegetable phase and shorter reproductive phase with high temperature in flowering and subsequent stages that result in low prolific silique and make disorder in transferring stored material to grain. In this experiment using N foliar application to decrease the adverse effect of delay in sowing is objective.
Materials and MethodsThe experiment was conducted in 2013-2014 in Ramin Agriculture and Natural Resource University of Khuzestan. Experiment was conducted as split plots in a randomized complete blocks design with three replications. In this experiment sowing date]optimum sowing (27 November), 17 December and late sowing (30 December) [were assigned to main plots and several time of N-foliar application with 5 percent density from urea (20 liter per ha), ]TO (control), T1 (foliar N application in rosette stage), T2 (foliar N application in budding stage), T3 (foliar N application in flowering stage)[ were placed in sub-plots in randomized way. Fertilizing was based on the results of soil examination. Therefore, 162 kg ha-1 of pure nitrogen (from resource urea) in the way of dusty application (1/3 after appearance of seedling on the soil, 1/3 in 3-4 leaves stage after thinning and 1/3 at the beginning of steam elongation) and 100 kg.ha-1 super phosphate triple in all plot was applied before planting. Each plot was consist of 8 planting line with 20 cm apart from each other and 4 m length. The data were analyzed by using SAS and mean comparison of data based on LSD test in 5% probably level.
Results and DiscussionLate sowing date and nitrogen foliar have significant effect on the yield and efficiency and uptake index of nitrogen. With delay in sowing because the flowering and silique formation stage faced with the heat tension, the vegetative phase, production of photosynthesis matter and growth all treatment like: yield, oil yield, biological yield, oil seed percent, nitrogen harvest index, nitrogen use efficiency, nitrogen utilization of agronomy efficiency and amount of nitrogen uptake, were decrease. But it should be pointed out that with delay in sowing the percentage of nitrogen seed and nitrogen of all bushes was increased.
The highest yield with mean of 3406.6 kg.ha-1 was relevant to first sowing date and least yield with mean 1803 and 1499.1 kg.ha-1 was achieved of second and third sowing date, respectively. In foliar treatment the highest yield was obtained from N foliar in budding and flowering stages and the least yield was obtained from control treatment.
Foliar in budding and flowering stages by increasing the green surfaces of plant, more benefit of sun radiation, increasing in photosynthetic activity were increase and in this way the seed yield and oil yield were increase. As well nitrogen harvest index was increased with increasing of assigned nitrogen to silique in canola and the reduction in wasting of nitrogen will be increased by consume it in appropriate time. With nitrogen foliar application because of availability of nitrogen in appropriate amount and adequate utilization of plant of nitrogen, caused to increase the nitrogen utilization of agronomy efficiency and nitrogen uptake amount.
ConclusionsThe results of this experiment showed that with delay in sowing the flowering and grain formation stages were faced to heat tension and can result in reduction in all treatment. The nitrogen foliar in heat stress caused an increase in seed yield, oil yield, dry mater, nitrogen harvest index, nitrogen utilization of agronomy efficiency and amount of nitrogen uptake. As the result, first sowing date and N foliar application in budding and flowering stages were best treatment in this experiment.

IntroductionPhosphorus (P) is an essential element in crop nutrition, which can be growth limiting or an environmental contaminant, if present in excess. On the other hand, tillage practices have a direct effect on behavior and availability of soil P. Since, application of different tillage methods lead to different patterns of soil phosphorus distribution, hence P fertilizer needs and P availability may be different in tillage systems. Researchers have found that the effects of tillage on P stratification depends on soil texture. Kimmel et al. (2000) reported that total P losses were significantly lower for NT than chisel-disk-field cultivator and ridge-till. Bahgar et al. (1998) showed that higher levels of P fertilizer improved shoot, root growth and the uptake of all nutrient elements in No till system. High levels of P also significantly enhanced the uptake of all nutrient elements except Zn and Cu.
Materials and MethodsThis study was conducted in Darab Agricultural Research Station in Fars Province, located in the south-western region of Iran (28° 47’N, 57° 17 ׳ E; 1120 m above sea level). The soil texture was loam. The experimental design was a randomized complete block with split factorial arranged in three replications. Tillage methods were main plots in two levels: conventional (CT) and reduce tillage (RT). Sub plots included phosphate fertilizer rates in three levels: 75%, 100% and 125% of recommended fertilizer (P1, P2 and P3, respectively) and P application methods in three levels: surface broadcast, banded starter and deep placed (M1, M2 and M3, respectively) in factorial technique. Corn hybrid 704 was planted using a four-row planter with 75 cm row spacing. Phosphorus concentration in the 0-15 and 15-30 cm soil layer and grain yield in the end of growth season were measured.
Results and DiscussionDifferent tillage systems had no significant effects on phosphorus concentration in the 0-30 cm soil layer. The results indicated that RT treatment had greater phosphorus accumulated in the surface soil (0-15 cm) and CT system reduced phosphorus concentration by 7. 2%. The difference in the P concentration between the two tillage systems can be attributed over a greater depth under conventional tillage (25cm) than under reduce tillage. Different fertilizer levels had significant effects on phosphorus concentration. In P1 treatment, phosphorus concentration was significantly less than P3 treatment. The minimum and maximum accumulation of available P was observed for 75 and 125% of recommended fertilizer in the 0-15 cm soil layer, respectively. The results indicated that there was Non-significant difference between P1 and P2 treatments. Also different phosphorus application methods had significant effects on phosphorous concentration. P concentration in surface broadcast treatment increased by 11. 2 and 16. 5% as compared to banded and deep placed treatments. The different tillage methods× fertilizer levels× application methods interactions on phosphorus concentration were significant. The maximum phosphorus concentration were observed for RT× P3× M1 treatments in the 0-15cm soil layer and the minimum occurred for the RT× P2× M3 and CT× P2× M3, respectively. The CT× P3× M3 interaction had a greater impact in increase of phosphorus concentration. The results also revealed that different tillage systems had no significant effect on grain yield. The most of yield was observed for RT system, although there was no significant difference between CT and RT systems. Phosphorus management methods had significant effects on corn yield. The lowest yield was observed for P3 treatment. The M2 treatment led to maximum grain yield as compared with M3 treatment.
ConclusionsThis study indicated that RT treatment had greater phosphorus accumulated in the surface soil (0-15 cm) and CT system reduced phosphorus concentration by 7. 2%. It also found no difference in phosphorus concentration between tillage systems. Reduced tillage seedbed preparation method coupled with broadcast P application lead to an accumulation of available P in the surface 0-15 cm soil layer.

IntroductionNowadays, salinity is one of the limiting factors for crop production in arid and semi-arid regions. On the other hand, sorghum (Sorghum bicolor L.) is a self-pollinated and short-day plant, which partly has been adapted to salinity and water stress conditions; also play an important role in humans, livestock and poultry nourishments. All studies have showed the positive effects of Silicon on growth and yield of plants in both normal and stress conditions. The aim of this experiment was to improve salinity tolerance of Sorghum by application of Silicon.
Materials and MethodsA split plot experiment based on randomized complete block design with three replications in both normal and salt stress conditions was carried out at research farm of Shahid Bahonar University of Kerman in 2013. Silicon treatments (0 and 6 mM) were considered as main plot and various sorghum genotypes (payam, sepideh, TN-4-70, TN-04-71, TN-04-39, TN-04-107, TN-04-100, TN-04-37, TN-04-68, TN-04-83, TN-04-62 and TN-04-95) were assigned to sub plots. The sodium silicate was used as silica source. The data were analyzed by SAS software using combine analysis. Means comparisons were accomplished by Duncan multiple range test at 5% probability level. Some of the measured traits were as follow: Relative water content (Ritchie and Nguyen, 1990), Relative permeability (33), leaf area index and chlorophyll index (by SPAD).
Results and DiscussionAccording to the results, use of silicon led to increase of RWC under salinity stress, while RWC decreased by 13% when no silicon applied. Salinity significantly decreased 1000-grain weight. Maximum grain yield obtained from TN-04-37 (987.6 g m-2) under normal condition with foliar application of silicon. Application of silicon under stress condition led to 38% increase in grain yield of Sepideh compared to control. Under salt stress, silicon also increased shoot dry weight in TN-04-107, TN-04-70, TN-04-37, Payam and Sepideh genotypes in comparison with control. Sepideh and Payam showed the lowest sensitive to salinity. In the other genotypes, harvest index decreased more than 50%. The minimum rate of harvest index was recorded for Payam genotypes under salinity stress and silicon treatments. Under stress conditions, silicon significantly increased leaf area index in Sepideh, Payam, TN-04-83, TN-04-68, TN-04-37, TN-04-100 and TN-04-62. Chlorophyll index also increased under salinity stress using silicon treatments. The highest chlorophyll index belonged to TN-04-68 and was significantly different from the others genotypes. Use of silicon improved the membrane stability in TN-04-37, TN-04-107, TN-04-100, TN-04-71, TN-04-70, TN-04-95 and Sepideh.
ConclusionsThe results showed that the use of silicon improved the physiological characteristics, yield and yield components of sorghum. Most of the genotypes showed a positive reaction to the applied silicon especially under stress condition. According to the results the maximum yield obtained from Sepideh (540 g m-2) and Payam (475 g m-2), respectively. It seems that among the studied genotypes, Sepideh, Payam and TN-04-100 had the best response to the silicon and showed the minimum sensitivity to the salinity stress. The most sensitive genotypes were TN-04-39, TN-04-68, and TN-04-62. In general it can be said that either under normal condition or salinity stress, silicon is able to improve yield production of grain Sorghum and its components.

IntroductionSalinity is a major abiotic stress that affects approximately 7% of the world’s total land area. Cotton (Gossypium barbadense L.) is considered as one of the most important cash crops which is widely used for agricultural and industrial purposes. Although, cotton is classified as one of the most salt-tolerant major crops but its growth and development are adversely affected by soil or water salinity. Understanding salinity and fertilizer interaction can mitigate salinity stress and improving crop yield. Potassium (K) is an essential nutrient that affects most of the biochemical and physiological processes that are involved in plant resistance to biotic and abiotic stresses. Proper management of K fertilizer is especially important in saline soils where K application might reduce the adverse effects of salinity on plant growth and yield. There is a little information about rate and application method of K on yield and yield component of cotton in saline condition. The objective of this study was to determine the effects of rate and application method of K on yield and yield component of cotton in soil and water saline condition.
Materials and MethodsThe experiment was carried out at Sabzevar Agriculture and Natural Resources Research center (Haresabad), 30km southwest of Sabzevar (32◦32N, 51◦23E and 1630 above mean sea level),in 2014.This experiment was conducted as split plot design based on randomized complete block design with three replications. Factors were: K rate (75 and 150kg ha-1 Solopotash (containing 50% K2O and 18% S) comprising the main plot and application method (25%at planting% at first flowering and 50%at early boll development (25P�继), 25%at planting% at first flowering and 25%at early boll development (25P绛), 25%at planting% at vegetative stage (5-8 leaves stage), 25% at first flowering and 25% at early boll development (25P�绛酾), 25% at planting% at vegetative stage and 50% at first flowering (25P�继), and 25% at planting% at vegetative stage and 25%at early boll development (25P绛) as the subplot. The seeds planted had been acid-delinted and treated with chemicals against seed and seedling diseases. Plots consisted of six rows spaced 0.5 min row and 0.2 m in plant (10 plants m-2) and 6 m in length. To evaluate yield components of cotton including plant height, sympodial branch number, boll number, boll weight, 10 individual plants were selected randomly from final harvest area. At harvesting time one meter square from the beginning and a half meter around each plot was removed as a marginal effect. The remaining area was harvested by hand for determine of lint and biological yield. Seed-cotton samples were ginned to separate the fiber (lint) from the seed. Lint percentage (%) was calculated as the weight of lint to weight of the seed-cotton. The statistical analyses were performed by SAS software Ver. 9.1. The mean separation was done through Fischer least significant difference (FLSD) test at alpha 0.05.
Results and DiscussionAnalysis of variance showed that boll weight, seed cotton yield and biological yield were significantly affected by potassium rate, whereas plant height, number of sympodial branch, boll number and lint percentage was not affected by potassium rate. All traits were affected by potassium application method except plant height and lint percentage. Plant height, boll weight, seed cotton yield and lint percentage were affected by interaction of potassium rate and application method. Increasing of K level up to 150 kg ha-1 increased boll weight (23.64%), seed cotton yield (17.67%), and biological yield (9.86%) in comparison with the application of 75 kg ha-1. Plant height, sympodial branch number and lint percentage did not respond to K rate. K application as 25% at planting% at vegetative stage (5-8 leaves stage), 25% at first flowering and 25% at early boll development (25P�绛酾�) had the highest boll weight, seed cotton yield, biological yield and lint percentage. In both K rate, split application of K at planting, vegetative stage, flowering and early boll development (equally at each stage) had the highest seed cotton yield. Potassium application at flowering or early boll development had more positive effect on seed cotton yield than planting or vegetative stage.
ConclusionsThe best seed cotton yield could be achieved with a combination of high dose of K fertilizer and split application of K at planting, vegetative stage, flowering and early boll development (equally at each stage). Increased K rate increased seed cotton yield because of improved boll weight and boll number in saline condition. Boll weight had more correlated with seed cotton yield than boll number. The K application as 25% at planting% at vegetative stage (5-8 leaves stage), 25% at first flowering and 25% at early boll development (25P�绛酾�) gave higher cotton yields than other split applications in saline conditions.

IntroductionCanary seed (Phalaris canariensis L.) is a forage plant from Poaceae family. This plant is drought tolerant. Canary seed is originally a native to Mediterranean region, which can be grown commercially in several parts of the word, especially in semi-arid conditions.
Increasing growth of population and lack of ability of pastures to satisfy the food requirement of animal has led to more interest in cultivating forage plants. In this regard, Canary seed having properties such as high yield per unit area, high tillering power, very fast growth and appropriate nutritional value, is of considerable importance and its cultivation development especially in arid and semi-arid regions can be effective in providing part of the country forage needs.
Optimum water requirement is considered as one the important factors to obtain a high growth and yield of the product. On the other hand, Iran is located in arid and semi-arid climate region of the world . Therefore, determination of appropriate amount of irrigation water can lead to the improvement of water use efficiency and preventing the water loss.
In order to achieve a high yield and desirable quality in plants one of the important requirements in agricultural planning is the evaluation of different systems of plant feeding. By applying an appropriate method in soil productivity, in addition to protecting the environment, optimization of water usage, reduction of erosion and protection of biodiversity can be increased. Therefore, gradually replacing chemical fertilizers with biological and organic fertilizers will result in providing feed requirements of plants, improvement of physical, chemical and biological conditions of soil and reduction of adverse environmental effects resulting from application of chemical inputs. The aim of this research was to study the effects of deficit irrigation and fertilizer management based on sole chemical and organic fertilizers or their integrated application on the yield and yield components of the forge of canary seed plant on the path of sustainable agriculture.
Materials and MethodsTo investigate the effects of different levels of irrigation water and integrated management of chemical and organic fertilizers on growth indices, yield and yield components of the Canary seed forage, an experiment was conducted as split plot based on a randomized complete block design with three replications at Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran during growing season of 2013-2014.
Different regimes of irrigation were in three levels (60, 80 and 100 percent of water requirement) in main plots and fertilizer treatments were in six levels (chemical fertilizer, vermicompost fertilizer, manure, chemical fertilizer vermicompost fertilizer, chemical fertilizer manure and control) in sub-plots. The amounts of treatment of nitrogen chemical fertilizer (200 kg ha-1 of urea source and 150 kg ha-1 of triple super phosphate) were applied in corresponding plots. The amounts of manure fertilizers (30 ton ha-1) and vermicompost (6 ton. ha-1) were determined and applied based on recommended amount of nitrogen. Water requirement of canary seed was estimated by the OPTIWAT software in continental condition of Mashhad . The volume of irrigation water for irrigation treatments was estimated based on 60, 80 and 100 percent of water requirement and was recorded as applied in each round of irrigation.
In order to harvest the forage in the emergence stage of 50% spikes of the Canary seed, 10 plants per plot were randomly chosen before harvest and traits such as per plant height and the number of tillers were recorded. Then, considering marginal effects from a surface equivalent to 1.4 m-2, plants were harvested from the height 3-5 cm and the weight of forage produced in each plot was measured and determined by weighing. Then, the harvested forage was transferred to the laboratory and two samples with approximate weight of 500 g were picked by quarter sampling. After weighing one of samples, it was transferred to the oven with the temperature of 75°C and after 48 hours the dry weight of samples were measured and determined by the balance with 0.001 g resolution. The second sample was separated into yield components of forage including leaves, stem and reproductive organs of plant. They were placed individually in the oven with the temperature of 75°C for 48 hours and then the yield components of the forage were determined.
Finally, resulted data were analyzed by the software SAS ver. 9.1 and mean comparison based on Duncan multiple-range test was conducted by the software MSTAT-C in the probability level of 5 percent.
Results and DiscussionExperimental results indicated that the effect of the different levels of irrigation water on the most traits examined except the percentage of leaf to the total dry content of canary seed was significant. The maximum yield of wet and dry forage was observed for irrigation regimes of 100 and 80 percent water requirement with 24.7 and 6.51 ton ha-1, respectively. In addition, the traits including plant height, the number of tiller in per plant, the spike percentage, the yield of wet and dry forage and forage protein also underwent manure treatment. The maximum yield of wet forage was obtained from vermicompost and animal manure treatment, the minimum yield was related to treatment without manure (control). The maximum yield of dry forage was observed for vermicompost and animal manure. Thus, consuming vermicompost or animal manure and sometimes their integration with chemical fertilizers will have a more significant yield. Furthermore, using deficit irrigation method, with 80 percent water requirement, in addition to saving water, desirable yield per unit area can be achieved.