In order to investigate the possibility of quinoa producing in Garmsar, Iran, a factorial experiment conducted in randomized complete block design with three replications in 2018-2019 growing season at Garmsar Agricultural Research Station. The factors were planting date at three levels (March 6th, April 1st and April 6th) and the three genotypes of quinoa (Q26, Q29 and Titicaca). Results showed that the effect of planting date was significant for all studied traits except the harvest index. Also, all studied traits were significantly different in all genotypes. Titicaca planted on March 6th had the highest Yield (2276 kg.ha-1).The grain Yield and Yield components decreased with the delaying the planting date. Compared to early plantings, Latest date, April 6th, led to reduction of all traits, especially grain Yield (about 50%). The results of simple phenotypic correlation between the studied traits showed that grain Yield per hectare had the highest correlation with plant Yield (0.877) and then with leaf area index (0.832), panicle weight (0.815) and number of branches per plant (0.745) that was significant at the 1% probability level.

Water Water deficit especially after heading is one of the most effective factors of wheat Yield loss in Iran and across the world and identifying the physiological traits related to plant resilience is of great importance in screening for tolerant varieties. The objective of this study was to evaluate the variation in stem reserves accumulation capacity and its relationship with remobilization in some wheat cultivars. 22 wheat cultivars were cultivated in a split plot design with three replications, full irrigation and 40% of field capacity being main plots. The amount of accumulation and remobilization was estimated by measuring internodes weight and stem soluble carbohydrates content (WSC). Significant genotypic variation among cultivars was observed under both normal and drought conditions. Maximum accumulation was found in lower internodes followed by peduncle and penultimate using dry weight measurement method. In WSC measurement method, however, maximum accumulation was observed in penultimate followed by lower internodes and peduncle. Cultivars ranking based on accumulation was also different in two methods. Drought stress caused decline in internodes weight, WSC and Yield and remobilization efficiency. The specific stem weight had the highest correlation with remobilization. Significant correlation was found between grain Yield and remobilization, specific stem weight and WSC.

Identifying the constraining factors of production and Yield gap is very important. Therefore; this research was performed to identify the production constraining factors of local rice cultivars. All management practices from nursery preparation to harvesting stages for 100 paddy fields of local rice cultivars were recorded through field studies, in Sari, from 2015-2016. In the CPA, the actual and calculated potential Yield were 4495 and 5703 kg/ha, respectively and the gap was 1221 kg/ha. The Yield gap caused by number of top-dressing variables was 324 kg/ha, equal to 27% of the total Yield gap. The Yield gap related to previous year of legumes cultivation was 218 kg ha-1, equal to 18% of the total Yield variation. Among the 10 variables entered in the CPA model, the effects of top-dress fertilizer application and its application frequency and foliar application were remarkable, which could compensate a significant part of the Yield gap (444 kg/ha, 37% of total) in the farmers’ fields by managing these variables. According to boundary line analysis (BLA) finding, actual Yield mean on the basis of optimal limit related to 12 variables under study was 5369 kg/ha, with 881 kg/ha Yield gap . Mean relative Yield and relative Yield gap for 12 variables (transplanting date, seedling age, number of seedlings per hill, planting density, nitrogen and phosphorous per hectare, nitrogen before transplanting, harvesting date, lodging problem, pest problem, diseases problem and weeds problem) were 83.64 and 16.35 kg/ha, respectively. Based on the finding, it can be stated that the model precision is appropriate and can be applied for both estimation of the quantity of Yield gap and determining the portion of each restricting Yield variables.

Water deficiency or drought is among the most important factors in reducing crop production (Heidari, et al., 2013). Water deficiency or water stress occurs when transpiration is more than water absorption (Alizadeh, 2008). One of the methods that researchers have been studying to increase water use efficiency and performance over the last decade is the use of superabsorbent polymers and deficit irrigation (Khyrabadi, et al., 2014). The superabsorbent polymer is a kind of hydrocarbon, which absorbs water several times as much as its own weight. Due to the drying of the root environment, the water inside these polymers is gradually evacuated and placed at the disposal of the plan, thus the soil will remain moist for a long time without the need for re-irrigation (Abedi Kupai, And Sohrsb, 2005). Considering that the most important advantage of superabsorbent application is reducing the effect of drought stress, this study investigated the effect of deficit irrigation and different levels of superabsorbent on Yield, Yield components and water use efficiency of lettuce.

Water and nitrogen are the main factors limiting the maximum Yield Achievement. Application of nitrogen fertilizer has great impact to increasing agricultural production. On the other hand, the high use of these fertilizers is due to the low efficiency of these fertilizers. This research was conducted in response to the challenges of water scarcity and inappropriate management of nitrogen utilization. To quantitate the reaction of the plant and calculate the water and fertilizer efficiency, two irrigation levels, full irrigation (I1) and deficit irrigation equal 30% (I2) as the first factor and two nitrogen levels of 200 (N1) and 160 (N2) kg per hectare, it was considered as a second factor. Experiments were carried out as field treatments and in lysimeters as a factorial in a completely randomized block design with three replications. The cultivars used were maize hybrid 611 and 704 mediator SC, which were cultivated in two seasons of spring and autumn, respectively. Based on the results of this study, leaf area index with higher nitrogen application in the same moisture conditions is increased. Nitrogen increase, while that enough water is available to the plant, increases the weight of 1000 seeds, grain Yield, biological Yield and harvest index. Optimum use of water and nitrogen fertilizer increases grain Yield and therefore increases water use efficiency. With increasing nitrogen content, nitrogen use efficiency decreases in corn cultivation. Under stress conditions, with increasing nitrogen consumption, fertilizer N-recovery efficiency is also reduced by decreasing the absorption of this element by the plant. The economic and biological efficiency of water use in autumn cultivation was more than spring cultivation. Low spring Yield and high rainfall during autumn crop period were due to the efficiency and more productivity of water use in autumn cropping. In Khuzestan weather conditions, the use of early cultivars is recommended instead of the mediator for spring crop due to coincide the pollination time with intense heat.

Wheat ground beetle Zabrus tenebrioides (Goeze) (Coleoptera: Carabidae) is an important wheat pest in Iran and some regions of the world. This pest causes damage to wheat by feeding on the root, stalk, and leaves. Farmers try to control this pest by the foliar application of different insecticides, but this method causes damage to the environment. To find an effective method to control this pest, the thiamethoxam insecticide (Cruiser®) efficiency was evaluated using seed treatment in this study. An experiment based on a randomized complete block design with four treatments and four replications was conducted in a field in Ramhormoz city, Khuzestan province (Iran). The treatments were 150 and 200 ml of thiamethoxam plus 2350 ml of water for seed treatment, 2,000 ppm of diazinon by field spraying at the wheat tillering stage, and a control. The results indicated that the average plant density in 150 and 200 ml of thiamethoxam (333.58 and 333.28 plant/m2, respectively) was more than those of diazinon (258.28 plant/m2) and the control (182.12 plant/m2). The average ear density in 150 and 200 ml of thiamethoxam (513.78 and 506.12 plant/m2, respectively) was more than those of diazinon (321.22 plant/m2) and the control (260.86 plant/m2). According to the present results, farmers can use 150 ml of thiamethoxam plus 2350 ml of water for 100 kg of seeds to control this pest by seed treatment.

SWAP model is called an agro-hydrological, agronomical-hydrological and eco-hydrological model. In this research, SWAP model was studied for estimation of soybean crop Yield, biological Yield and available moisture percentage in soil during growing season. In this study, first of all results were sensitivity analyzed and calibrated based on soybean cultivation for four furrow irrigation scenarios in agronomical years 2008-2009. Then it was validated based on field results in agronomical year 2009-2010. The results of this study showed that this model simulated crop Yield better than biological Yield. Also sensitivity analysis of the model showed that SWAP model is sensitive to input data of residual moisture and saturation hydraulic conductivity and with the least variation in soil input including saturation hydraulic conductivity and residual moisture, output results varied greatly. Based on statistical analyses, with a lot of existing variables, SWAP model can estimate the soil moisture, leaf area index, water use efficiency and crop Yield well because in all cases coefficients of determination are higher than 0.8 (are equal to 0.86, 0.87, 0.89 and 0.93 respectively) and root mean square error is less than standard deviation of data and mean comparison T-test did not show significant differences between the simulated and measured amounts.

In order to investigate the Yield and Yield components of four lentil genotypes (Local line, Local bulk, ILL-10314 and ILL-6037 genotypes) as affected by three urea nitrogen levels including 0, 45 and 90 kg ha-1, a factorial experiment based on randomized complete block design with three replications was carried out in agriculture and natural resources research center of Ardabil, during 2008. Based on the results, different nitrogen levels, except for grain Yield, agronomical and recovery nitrogen use efficiency, did not affect the other studied traits. While the impact of genotypes was significant on all traits. Local line had the lowest number of full pods, number of grain per pod and grain per plant, showed the highest grain Yield. The lowest grain Yield was observed in the ILL-10314 genotype. Lower 100- grain weight in this genotype may be of the reasons for the low grain Yield despite of the high number of grain per plant, grain per pod and the full number of pods per plant. The lowest number of the full pod per plant was observed in ILL-6037 genotype. This genotype having the highest 100-grain weight was placed in the same group with the local line and bulk, in terms of grain Yield. The highest agronomical and recovery nitrogen use efficiency were achieved using the 45 kg ha-1 and Local bulk genotype.