---

In order to investigate the Effect of different levels of nitrogen and plant density on yield, and some morphological sunflower cultivars, experimental farm in 2009 in the College of Agriculture University researcher Ardebili A split plot factorial design based on a randomized complete block with three replicates was carried out. Nitrogen treatments included (zero, 75 and 150 kg per ha) assigned to main plots and levels of plant density (8, 10 and 12 plants per square meter) and two varieties were Urofelor and Armavirsky in sub plot. Head and stem diameter, plant height, number of kernel per disk, number of leaves at the final of harvesting and grain yield measured. Sunflower cultivars was significant difference on the stem diameter, plant height and number of kernel per disk but different levels of nitrogen and plant density were significant difference on the for all traits measured. The highest grain yield was obtained, 262 gr /m2 in 150 kg N/ha× Armavirsky. Increasing plant density by increasing the number of heads per unit area, will affect performance. Considering the excellence level of 80 thousand plant density and fertilizer level of 150 kg ha compared to other treatments in terms of grain yield, the amounts of nitrogen and planting density to achieve adequate performance in the test area and similar areas is advisable.

---

Foliar urea application is one of the nitrogen (N) application methods in cereal grain crops. Yield and yield components may be affected by foliar urea application. To investigate the effect of rate and time of such treatment on yield and yield components of two winter wheat cultivars, a field experiment was conducted at Badjgah, Agricultural Research Farm (29° 36
N, 52° 32
E) of Shiraz University, Shiraz, Iran during 1998-99 growing season. The experimental treatments were two winter wheat cultivars (‘Phalat’ and ‘Marvdasht’), five levels of foliar urea application (0, 8, 16, 24 and 32 kg N ha-1) at three times of application (pre-anthesis, anthesis and post-anthesis). The experimental design was a randomized complete block one with treatments arranged as split-plot factorial with three replicates. The results showed that cultivars responded differently to the rate of foliar N feeding so that, over the growth stages, Marvdasht cultivar produced significantly greater grain yield (+19%) by application of 8 kg N ha-1, whereas, the Phalat cultivar had greater grain yield (+27%) when it was supplied by 16 kg N ha-1. Increase in grain yield was mainly due to an increase in number of grains ear-1. The fertile ears m-2 and mean grain weight were not significantly affected by foliar urea feeding, however, the harvest index and biological yield were increased. The pre-anthesis foliar feeding with urea resulted in higher yields as compared with later applications. Also the early foliar urea feeding increased the harvest index from 42.4% to 46.9% at 32 kg N ha-1 in Marvdasht cultivar. The results of the present investigation also suggest that late foliar application could decrease nitrogen use efficiency.

---

Spatial patterns of soil fertility parameters, and other extrinsic factors need to be iden-tified to develop farming practices that match agricultural inputs with local crop needs. Little is known about the spatial structure of yield and weed density across fields. In this study, geostatistics was used to describe and map spatial patterns of soil total nitrogen, available phosphorus, available potassium, grain yield and density of Sisymbrium irio L. (tumble mustard), as a common annual weed of wheat fields at Shahre Kord university. The spatial continuity of each variable was examined by variogram function. The variograms showed that the distribution of all variables is not random but spatially-dependent as their estimated variogram values increase with increasing distance. The av-erage range values were 26.5, 23.4, 31.4, 27.7, and 27.2 m for total nitrogen, available phosphorus, available potassium, grain yield and weed density, respectively. Thus, the range beyond which the property is not longer spatially dependent was almost the same for total nitrogen, grain yield and weed density. This implied close spatial interactions among these variables over the field. Applying the variogram models with the kriging al-gorithm, the values for each variable were estimated on a 55 grid. The disrribution of all variables is spatially dependent and continuous over a short distance. Furthermore, the maps illustratc a joint spatial dependence between grain yield and weed density. Spatial patterns of soil properties identified by these geostatistical techniques are of great impor-tance in the fertility management of spatially variable soils. By studying the spatial struc-ture of yield and mapping, it could be used in determining different factors controlling yield over the field. Moreover, a better knowledge of annual or perennial weed density distribution over fields might be helpful in better designing long-term field experiments in weed control programs.

---

The responses of yield and yield components of 24 advanced bread wheat genotypes to pre- and post-anthesis drought stress conditions were studied at Ardabil Agricultural Re-search Station during the 1997-2000 cropping seasons. Results showed that genotypes produced significantly lower spikes No./m2, seeds No./spike and grain yield under pre- than in post-anthesis drought stress conditions. However, an average of 1,000 kernel weight of genotypes under pre-anthesis was higher than under non-stress and post-anthesis drought stress conditions. Selection based on TOL and SSI identified the drought tolerant genotypes with low grain yield. However, selection based on MP, GMP and STI identified drought tolerant genotypes with a high yield. Genotypes No. 13, 14 and 21 were determined as desirable genotypes based on their high grain yield under non-stress, pre-anthesis and post-anthesis drought stress conditions. The interaction effect of genotype x year was significant for membrane stability and membrane damage, however, the interac-tion effect of genotypes stages of measurement (booting and heading) were not signifi-cant. On the basis of these results, genotypes No. 13, 14 and 21 with low membrane dam-age were also identified as drought tolerant genotypes. It can be concluded that the labo-ratory test can be an useful tool in a breeding program for improving drought tolerance in wheat.

---

The introduction of canola (oilseed rape; Brassica napus L.) as a new source of vegetable oil production in Iran prompts evaluation of the performance of this crop under different tillage systems. A field experiment was conducted to determine the impact of depth and intensity of tillage on soil physical properties, crop establishment and yield of irrigated winter canola in a loam soil (Typic Haplargids) near Isfahan in central Iran. In a split-plot design, three primary tillage treatments consisted of moldboard plowing to 20 cm (MP20), two passes of a cultivator first to 10 and then to 15 cm (2TC15), and one single pass of cultivator to 10 cm (TC10), were combined with two seedbed preparation treatments (four passes with a disk harrow as opposed to a single pass with a rotary tiller). Results showed that the soil bulk density in the 0-5 and 5-10 cm layers were not significantly affected by primary tillage treatments. Soil penetration resistance (PR) in the 0-10 cm layer was significantly higher in 2TC15 compared to moldboard plowed soil; however, no significant effect of primary tillage was detected on PR in the 10-20 cm depth. A single pass by a rotary tiller was as effective in seedbed preparation as four passes of a disk harrow, as assessed by bulk density, penetration resistance and the percentage of emergence. The number of plants per square meter at final emergence and at harvest was statistically similar for both the seedbed preparation methods. Mean canola total dry matter biomass was 10,020, 9,860 and 10,410, kg ha-1 and dry grain yield was 2,340, 2,410 and 2,880 kg ha-1 under MP20, 2TC15 and TC10, respectively. However, the effects on mean crop yield were non-significant (P 0.05). The mean oil content of the 2TC15 (40.1%) was significantly lower than the MP20 and TC10 treatments, 43.7 and 42.3%, respectively. Lack of yield response to tillage treatment may have been the result of achieving a good seedbed (aggregate mean diameter of less than 15 mm) under all tillage methods, which help to obtain sufficient plant establishment. These results indicate that the yield of irrigated winter canola is not sensitive to reduction in the depth of primary tillage or intensity of secondary tillage. With reduced tillage, an optimum plant per unit area can also be achieved. Overall, TC10 combined with a single pass of a rotary tiller was considered to be agronomically desirable, due to the absence of grain yield difference compared with both the MP20 or 2TC15 systems and reduced tilling depth.

---

Eighteen wheat breeding lines were evaluated along with two check cultivars across nine locations of temperate zone of Iran during two crop seasons (2003-2004 and 2004-2005). Field records were taken for some important traits especially grain yield. Combined ANOVA for nine locations in the first season and for seven locations in both seasons was undertaken. In each case, additive main effects and multiplicative interaction analysis (AMMI) was employed and the biplot of the Interaction Principal Components (IPC) were evaluated for stability and adaptation relationships among genotypes and locations. IPC1, IPC2 and IPC3 accumulatively defining 78.4% of genotype×environment (G×E) interaction variation were found out as significant in the first crop season. Biplot of first two IPCs identified at least two sub-regions among the locations. Some genotypes (M-82-7 and M-82-17) showed specific adaptation toward one of the drought-prone sub-regions. For the combined data of both seasons, only IPC1 was significant defining 41.5% of G×E interaction variation. Thus, plot of IPC1 along with grain yield means were employed for an interpretation of adaptation relationships. Entries M-82-8, M-82-9, M-82-11 and M-82-15 showed specific adaptation to Mashhad station which was interactive and particular in behavior. The results indicated that AMMI is an informative method of stability and adaptation analysis to be employed in practical plant breeding and subsequent variety recommendations.

---

It is suggested that cultivars of wheat (Triticum aestivum L.) with regulated growth and development would be able to produce higher yields under water-limited conditions, which is crucial in future food production. Water use efficiency (WUE) is worthy of exploration in this regard. In this study, the effects of nitrogen fertilizer levels (0, 40 and 80 kg Nha-1) and a plant growth retardant (Chlormequat Chloride = CCC) on WUE of four dryland wheat cultivars (Agosta, Nicknejad, Azar-2 and Fin-15) were examined in a field experiment during 2006-07 and 2007-08 growing seasons at College of Agriculture, Shiraz University, Iran. The results showed that there existed significant differences between cultivars for grain yield, biomass and WUE. In the first season, the highest grain yield and biomass production (192.4 and 431.2 gm-2, respectively) were obtained from Nicknejad cultivar, CCC application and using 80 kg Nha-1, and in the second season, from Azar-2 cultivar (121.5 and 333.5 gm-2, respectively). CCC and nitrogen had significant effects on photosynthesis rate and WUE in both seasons. Interaction of CCC and 80 kg Nha-1 on WUE were significant in both seasons (1.24 and 2.72 gm-2mm-1, respectively). It is suggested that interactive application of CCC and nitrogen fertilizer could have beneficial effects on wheat grain yield under similar agro-climatic conditions.

---

Drought is the most restricting factor in agricultural production in arid and semi-arid regions. This research was conducted on 19 facultative and winter wheat genotypes grown under normal irrigation (N), early post-anthesis (S₁), and late post-anthesis (S₂) drought stress conditions. The experiments were conducted at Karadj, Arak, and Jolgehrokh Agricultural Research Stations in Iran, during 2008-11 cropping seasons. Stress reduced grain number per spike, thousand grain weight, grain weight per spike, harvest index, biological weight, and grain yield.Effect of environment, irrigation, and genotype on most of the traits, including grain yield, was significant. Remobilization, efficiency of remobilization, and pre-anthesis photo-assimilate contribution to grain filling increased under drought stress condition. Correlation coefficients between those traits and grain yield were significantly positive under N, S₁, and S₂ conditions. Based ondifferent drought tolerance indices, the improved line Alvd//Aldan/Ias58*2/3/Gaspard was identified as the most tolerant genotype under anthesis and post-anthesis drought stress conditions.It also had the highest remobilization, efficiency of remobilization, and pre-anthesis photo-assimilate contribution to grain fillingunder drought stress conditions.

---

 Soil erosion by water is the main factor of land degradation, particularly in semi-arid regions where soil productivity is usually low and lowering soil quality can severely decrease crops yields. This study was done in an area of 900 km² in the semi-arid agricultural region of Hashtroud in northwestern Iran to determine the relationship between soil productivity and soil erodibility. Wheat grain yield (WGY) and soil erodibility factor (K) were measured separately at 108 plots in 36 dry-farming lands under natural rainfall conditions for a two-year period from March 2005 to March 2007. Based on the results, significant differences were observed among the lands in WGY (P< 0.001) and K (P< 0.001). These differences were attributed to variations of soil properties among the lands. There was a negative relationship between WGY and K (R²= 0.77). Multiple regression analysis indicated that both WGY and K were significantly related to aggregate stability and infiltration rate, with a determination coefficient (R²) of 0.74 and 0.90, respectively. Organic matter and calcium carbonate equivalent were the most effective soil properties that enhanced both aggregate stability and infiltration rate. The study revealed that soils with a lower percentage of water-stable aggregates and a lower infiltration rate also tended to have a higher susceptibility to erosion and a lower potential for crop production.

---

Growing demand for wheat grain with optimal technological parameters results in looking for the possibilities of accurately meeting the plant needs. Environmental conditions in the surroundings of germinating grains can be improved by application of humic preparations. Qualitative features of grain can be also changed by foliar application of potassium, which is the activator of enzymes catalysing synthesis of proteins. The aim of the study was to assess the effect of seed dressing with Humistar (12% of humic acids, 3% fulvic acids) and foliar application of Drakar (31% K₂O, 3% N) on the spring wheat yield and qualitative features of the grain, namely, 1,000 Kernel Weight (TKW), Hectolitre Mass (HM), Grain Glassiness (GG), Falling Number (FN), total Protein Content (PC), Wet Gluten content (WG) and Sedimentation Value (SV). The experiment was established in the randomized blocks design in a soil classified as Mesic Typic Hapludalfs. The effect of the applied preparations on yield was non-significant, but it was favourable for grain quality. Application of Humistar resulted in an improvement of TKW, HM, GG, PC, WG and SV as compared with the control. Results of the application of Drakar were similar to Humistar in affecting HM, WG and SV, and in the case of PC, the result was even better. The effect of Drakar on GG, although favourable compared to the control, was smaller than after the application of Humistar. Seed dressing with Humistar or foliar potassium fertilization with Drakar are agrotechnical methods that can improve the qualitative features of milling wheat grain.

---

Missing values in a data set is a widely investigated problem. In this study, we propose the use of support variables that are closely associated with the variable of interest for the imputation of missing values. Level of association or relationship between the variable of interest and support variables is determined before they are included in the imputation process. In this study, the barley (Hordeum vulgare) grain yield in the semi-arid conditions of Cyprus was used as a case study. Monthly rain, monthly average temperature, and soil organic matter ratio were selected as support variables to be used. Multivariate regression employing support variables, bivariate, kernel regression and Markov Chain Monte Carlo techniques were employed for the imputation of missing values. Obtained results indicated a better performance using multivariate regression with support variables, compared with those obtained from other methods.

---

To identify the important features of triticale that contribute to improving grain and biomass Water Use Efficiency (WUE_g and WUE_b, respectively), grain yield, and Nitrogen (N) remobilization, a 2-year side-by-side experiment was carried out on triticale with different nitrogen sources and water regimes, in a typical Mediterranean environment of Iran. There were two levels of water regimes: Normal Irrigation (IR_N) and irrigation cut off after anthesis stage (IR_MD). Rain-fed treatment (IR₀) was included in the second year. Four N sources including Azospirillum brasilense (Bio), Azospirillum brasilense+75 kg N ha^-1 as urea (Bio+N₇₅), 150 kg N ha^-1 as urea (N₁₅₀), and control unfertilized (N₀) plots were used. This study showed that the highest grain yield (6,258 kg ha^-1) was achieved by chemical N fertilizer application (N₁₅₀) under IR_N. In contrast, the application of Bio+N₇₅ resulted in the highest grain yield as compared with the other N sources under IR_MD (4,409 kg ha^-1) and IR₀ (2,960 kg ha^-1) conditions. Water stress significantly increased WUE_b at all N sources. However, WUE_g slightly increased by IR_MD and then sharply decreased by IR₀ in all N sources, except N₁₅₀ plots, where WUE_g drastically decreased by water stress imposed by IR_MD and IR₀. The Bio+N₇₅ treatment had the highest N remobilization. Although N remobilization was not affected by IR_MD in dryer year, it increased by IR_MD (8.4%) in the relatively wet year. Totally, for a more sustainable farming system in arid Mediterranean conditions, integration of biofertilizer and chemical N fertilizer could be successfully used for increasing grain yield, WUE, and N remobilization of triticale, especially under deficit irrigation regimes.

---

 To remain viable in facing with increasing costs, farmers need to increase irrigation Water Productivity (WP) and save Virtual Water (VW). To evaluate the WP and VW for five barley cultivars (Reyhan, Nimrooz, Valfajr, Zehak, and Yusof) under different irrigation regimes [well-watered (100% Field Capacity; FC), mild water stress (75% FC), severe water stress (50% FC), and extremely severe water stress (25% FC)], a two-year field experiment was laid out in Darab, Fars Province, Iran, during 2014 and 2015 growing seasons. Results showed that change in moisture stress from well-watered to extremely severe water stress, was associated with a significant increase in WP and Economic Water Productivity (EWP) for straw and biological yield. A positive linear relationship was found between grain yield and VW, and the lowest VW was found in the range of 3,314 to 3,451 kg ha^-1 of grain yield. Interestingly, for all irrigation regimes, Zehak and Yusof cultivars had greater WP for the grain yield. Furthermore, VW for biological yield of Yusof cultivar sharply decreased from 0.410 m³ kg^-1 in well-watered treatment to 0.164 m³ kg^-1 under extremely water stress conditions in both years. Comparison of Zehak and Yusof cultivars with Reyhan, Nimrooz and Valfajr showed that under water stress conditions, the first two cultivars showed significantly lower VW for the grain yield than the other cultivars. Indeed, Yusof and Zehak cultivars showed the lowest Economic Virtual Water (EVW), which was in the range of 0.054 to 0.091 m³ 1,000 Rials^-1, under extremely water stress conditions. Thus, to achieve optimum EWP and EVW and attaining stable yields under semi-arid conditions, suitable barley cultivars such as Zehak and Yusof could be irrigated with less water (i.e. 25 to 50% FC).

---

To investigate the effect of inoculation with Rhizobium legominosarum and Pseudomonas fluorescens on grain yield, leaf area index, and dry matter accumulation and allocation of Vicia faba L., an experiment was conducted as a split-plot in a randomized complete block design with four replications at Agricultural Research Station of Golestan Province, during the cropping seasons of 2015-2017. As the main-factor, Rhizobium was considered at two levels of with and without inoculation, while the sub-factor included Pseudomonas in density levels of 0, 9×10³, 9×10⁵, 9×10⁷, and 9×10⁹ cells or CFU mL^-1 of inoculants. A logistic model by SAS, was used in order to estimate the changes in the leaf area index and the dry matter accumulation. Combined analysis of variance for the two years of study indicated that the climatic conditions influenced the bacteria effects. In the second year (less temperature and rainfall), the traits (maximum leaf area index, maximum dry weight and grain yield) indicated a significant reduction in comparison with the first year. P. fluorescens had a significant positive effect on grain yield in the two years. None of the bacteria had significant effect on maximum leaf area index. Results of the first year showed a positive effect of the inoculation of Rhizobium on maximum dry weight (8%) in comparison with the control. Co-inoculation of Rhizobium with Peseudomonas (9×10⁵ CFU mL^-1) led to the greatest dry matter distribution coefficient for stems in podding stage. In the second year, Peseudomonas (9×10⁹ CFU mL^-1) increased maximum dry weight (23%) in comparison with the control. Also, the density increase of Peseudomonas under co-inoculation with Rhizobium led to a significant reduction of the day to maximum LAI. In conclusion, co-inoculation Rhizobium with Pseudomonas can have a positive effect on the growth indices of faba bean.

---

The objective of this study was to assess changes in proline, Glycine Betaine (GB), photosynthetic pigment concentration, Membrane Stability Index (MSI), and grain yield of wheat cultivars induced by Supplemental Irrigation (SI) in the terminal growth stages. Two field experiments with four irrigation levels (rainfed, SI at booting stage, SI at booting and anthesis stages, SI at booting, anthesis, and grain filling stages) and five cultivars (Rejaw, Sardari, Homa, Azar2, and Sirwan) were conducted during the 2015-2017 growing seasons. Results indicated that, overall, SI increased cultivars' chlorophyll concentration, MSI, and grain yield. Proline and GB highly accumulated under drought stress, but rapidly decreased after SI; the severity of the decrease in proline concentration was more remarkable. Sardari and Azar2 cultivars exhibited greater MSI, proline, and GB accumulation during drought stress and more rapid recovery from drought. Our results suggest that the ability of the wheat cultivars to maintain functions during drought and recover after SI during the terminal growth stage is essential for determining final grain yield.

---

Utilizing new irrigation techniques to introduce cultivars into paddy fields experiencing water scarcity is one way to combat water shortage and increase water productivity. To this end, this experiment was conducted as a strip plot in a randomized complete block design with three independent replications over two years (2016 and 2017) at the Rice Research Institute of Iran, Amol, Iran. Ten rice genotypes (V1 to V10) were subjected to three types of irrigation systems, including conventional Flood Irrigation (FI) and Alternate Wetting and Drying (AWD) at 10 (AWD10) and 20 (AWD20) cm below the soil surface. These results demonstrate that AWD10 and AWD20 methods reduced water consumption by 20 and 17%, respectively, compared to the conventional methods. This decreased water usage resulted in 1.4 and 0.2% yield losses compared to the conventional flood irrigation system. Moreover, milling recovery in flood irrigation (68.7%) was lower than AWD10 and AWD20 methods (69.6 and 69.8%, respectively). In conclusion, Neda, Shiroodi, and 8611 rice genotypes showed a better response to AWD irrigation, and may be considered as suitable genotypes for increasing water productivity in paddy fields.