Rapid and efficient recovery from water deficit stress may be one of the key determinants of drought adaptation in plants. The present study was designed to investigate drought stress tolerance and recovery in promising lentil lines at the flowering stage. For this, a factorial experiment based on the completely randomized design was conducted with three replications. The factors included 6 lentil lines, drought stress (control (irrigation at 80% FC or 20% moisture depletion), medium stress (irrigation at 55% FC or 45% moisture depletion), and severe stress (irrigation at 30% FC or 70% moisture depletion)), and three sampling times (three and six days after drought, and recovery (two days after re-irrigation)). Drought stress caused a decrease in chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, protein, yield, and yield components. The reduction of these traits was more remarkable at six days after stress. However, during the recovery time remarkable increase was observed in these traits. The results showed that the correlation between H2O2 and MDA was significant and positive. Furthermore, drought stress increased the amount of proline, H2O2, and MDA, which resulted in an increase in the activity of antioxidant enzymes (catalase, polyphenol oxidase, and peroxidase). An increase in the intensity and duration of the drought stress also caused an increase in H2O2 and MDA content and the activity of antioxidant enzymes. In addition, in the recovery conditions, a significant reduction in the destructive effects of stress (H2O2, MDA content) and the activity of antioxidant enzymes was visible. The results of the present study indicated that the effects of drought stress on lentil lines yield and yield components (seed number, number of pods, 100-seed weight, and seed yield) were varied. Drought stress at the flowering stage decreased the number of seeds and pods per plant, and 100-seed weight, which led to yield losses. Although line 2 had the highest yield under normal and drought stress conditions, line 1 exhibited the lowest yield under stress conditions. Based on the results of this experiment, line 2 seems to be a suitable line for culture in the regions challenged with water deficit stress.

This study was conducted to investigate the effect of foliar application of amino acids on yield and yield components of oil rapeseed under late-season drought stress conditions. The experiment was conducted as factorial based on a randomized complete blocks design in the research farm of the Faculty of Agriculture at Tarbiat Modares University during the 2021-22 growing season. The experimental treatments were irrigation regimes at three levels (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming) and foliar spraying at five levels (no foliar, foliar spraying 0, 1, 2, and 3 g amino acids per liter of distilled water). The results showed that plant height, shoot dry weight, 1000-seed weight, harvest index, and biological and grain yield, number of seeds per pod, and the number of pods per plant were significantly affected by the interaction of irrigation regimes and foliar spraying. The highest plant height (166.5 cm), 1000-seed weight (3.58 g), number of pods per plant (131.4) and grain yield (4514 kg ha-1) were obtained by foliar spraying of two g amino acids per litre under normal irrigation conditions. According to the results, foliar spraying 2 g amino acids per liter had the most positive effect on the yield and yield components of oil rapeseed in all irrigation regimes (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming). Therefore, upon approving in future research it could be recommended to use foliar spraying with 2 g amino acids per liter in oil rapeseed cultivation.

In order to compare 25 genotypes of bread wheat in terms of morpho-physiological and biochemical traits, an experiment was conducted in a randomized complete blocks design with three replications in the rainfed and irrigated conditions at Razi University, Iran, in 2016-2017. GT-biplot was used to evaluate genetic diversity and to identify stable genotypes with high yield and drought tolerance. Combined variance analysis showed that there was high variability among genotypes for the most of traits. Examining the correlation of traits in two environmental conditions showed that morpho-physiological traits; especially yield components, were the most related to yield. The results of the GT-biplot method showed that the first and second principal components explain 41.7% and 40.1% of the total changes in rainfed and irrigated conditions, respectively. Based on the GT-biplot analysis diagrams of genotypes 10, 15, 6, 13, 2, 14, and the Pishtaz cultivar in terms of physiological traits, yield and its components and the traits related to stem and spike in irrigated conditions, and genotypes 10, 15, 6, 18, and 17 in terms of biochemical traits, yield and its components, and traits related to stem and spike in rainfed conditions were recognized as superior genotypes. The genotypes 2 and 6 in irrigated conditions and the genotype 6 in rainfed conditions had the lowest genotype×trait interaction. Finally, the genotypes 10, 15, and 6 were superior in two environmental conditions and the genotype 6 had the least interaction effect in both conditions. Therefore, these genotypes can be used in breeding programs.

To investigate the effect of organic fertilizers on the quantitative and qualitative characteristics of sugar beet under different moisture conditions, a study was conducted as a split plot experiment based on a randomized complete block design with three replications in Mahabad city in 2021. Irrigation treatments, including irrigation after 60 (normal), 90 (mild stress), and 120 (severe stress) mm evaporation from the class A evaporation pan, and organic fertilizer treatments (control, vermicompost, manure, and humic acid) were placed in main plots and sub-plots, respectively. Severe water stress conditions reduced the content of chlorophyll a (22.82 %) and relative water content (RWC) (24.35 %) and increased the content of proline (47.43%), beta glycine (17.89%), catalase (21.30 %), malondialdehyde (47.95 %) and water use efficiency (WUE) (23.83%) compared to normal irrigation conditions. Also, the application of vermicompost increased the amount of chlorophyll a, RWC, proline, glycine beta, catalase content, and WUE by 29.11, 20.15, 34.83, 14.98, 13.70, and 21.56 percent, respectively, and decreased the content of malondialdehyde about 18.53% in comparison to control. In this study, the highest stomatal conductivity (51.01 mol.m-2s-1), chlorophyll b content (16.3 mg.g-1FW), carotenoid (4.27 mg.g-1 FW), roots yield (78.33 t.ha-1) and the lowest content of hydrogen peroxide (0.96 μmol.g-1FW) allocated to the vermicompost treatment under normal irrigation conditions. Root yield showed a positive and significant correlation with stomatal conductance, chlorophyll b, carotenoid, RWC, and WUE, but a negative and significant correlation with catalase enzyme activity, hydrogen peroxide content, malondialdehyde, and sugar content.

This research was done with the aim of checking energy and economic indicators and the amount of greenhouse gas emissions in the production system of two products, tomato and onion in 2021 and 2022 in Alborz province. The information required for this research was obtained through interviews with farmers and completing questionnaires. The results of this study showed that the highest energy input, energy output, and net energy in onion were obtained in Savojbolagh city at the rate of 21324.8, 105600, and 24275.3 Mj.ha-1, respectively. In tomato, the highest input energy, output energy, and net energy was 73799.8, 56000, and -13495.4 Mj.ha1, respectively (in tomato, net energy is negative due to the greater input energy than output energy). The highest energy efficiency consumption was obtained in onion and tomato, 1.4 and 1.32 respectively. In the comparison of energy efficiency, the highest value in onion and tomato were observed 0.82 and 0.99 Kg.mj-1. Among the various inputs in the onion and tomato production systems, diesel, nitrogen chemical fertilizer, animal manure, irrigation water, gasoline, and manpower had the largest share in input energy in the order of priority. Onion and tomato by producing 3065.8 and 3045.4 kg of CO2 per hectare, played a role in the emissions of greenhouse gases. The analysis of economic indicators also showed that onion with a net income of 9608.7 $.ha-1 compared to tomato with a net income of 4840.3 $.ha-1 has generated more income. According to the obtained results it can be possible that reduce the amount of energy input and greenhouse gas emissions and thus, provide the necessary conditions for the establishment of more sustainable agriculture by modifying production methods such as using modern irrigation methods and also replacing animal and biological fertilizers with chemical fertilizers.

This experiment was conducted to investigate the effect of crop arrangement and different levels of nitrogen on the morphological characteristics, photosynthetic pigments, and nutrients of sunflower seeds, as a split plot experiment in a RCBD design with three replications in 2021. The main plots included five different patterns of spatial arrangement (square, normal rectangle, wide rectangle, triangular, and mixed cultivation systems). Different levels of nitrogen chemical fertilizer (urea) in three levels (application of 100, 75, and 50% of the plant's fertilizer requirement) were placed in sub-plots. The results showed that the maximum leaf width (40.3 cm), leaf area index (4.64), number of leaves (29.2), stem diameter (3.95 cm), and plant height (177.3 cm) were obtained from the treatment of triangular planting arrangement. In addition, the triangular planting arrangement and then the square planting arrangement had the highest content of chlorophylls and carotenoids compared to the other planting arrangements, and the lowest content of chlorophylls and carotenoids were observed in the wide rectangular planting arrangement. Moreover, the results showed that the maximum protein, nitrogen, phosphorus, and potassium of sunflower seeds were obtained in the triangular planting arrangement (17.15, 2.98, 0.54, and 1.73%, respectively), and no significant difference was observed in the triangular planting arrangement between different levels of nitrogen. Generally, the triangular crop arrangement by improving the growth characteristics of sunflower resulted in maximum grain yield and 50% reduction in urea consumption, because the yield of sunflower in the mentioned treatment did not show a significant difference with the application of 100% urea fertilizer; Therefore, the triangular cultivation arrangement is introduced as the best cultivation system for sunflower.

Improving the nutritional status of plants is an effective method for enhancing their ability to withstand drought stress. To evaluate the quantitative, qualitative, and antioxidant properties of castor plant under water deficit conditions stress and foliar application of chemical fertilizers, an experiment was conducted as a split-plot design in a completely randomized block design with three replications. The first factor was irrigation levels including control (normal irrigation), irrigation after 80 mm and 140 mm evaporation from the pan evaporation in the main plots, and eight spraying chemical fertilizers (sulfur, potassium, nitrogen, sulfur+potassium, sulfur+nitrogen, potassium+nitrogen, sulfur+potassium+ nitrogen and control (no spraying)) were included in subplots. The highest proline content, catalase, peroxidase, superoxide dismutase, and total phenol were obtained under irrigation after 140 mm of evaporation conditions and foliar application of nitrogen+potassium+sulfur. Also, the highest grain yield, oil yield, and the lowest oil percentage were observed in the nitrogen+potassium foliar treatment under irrigation conditions after 20 mm of evaporation. Although the content of malondialdehyde increased in water deficit stress treatments, nitrogen+potassium+sulfur and nitrogen+potassium foliar application significantly reduced the peroxidation of membrane lipids (malondialdehyde) under irrigation conditions after 80 and 140 mm of evaporation compared to the control treatment. In conclusion, foliar application of chemical fertilizers in castor can improve the resistance to water stress by strengthening the antioxidant system and then increase its grain and oil yield.

This research was carried out in order to evaluate the biochemical and agronomic traits of dryland chickpea intercropped with dragon’s head in Saqqez city (Kurdistan province). It was conducted as a factorial split-plot experiment, arranged in a randomized complete block design, with three replications during the 2021-2022 cropping year. Treatments included three planting times (autumn, expecting, and spring) as first factor, three chickpea cultivars (Saral, Nosrat, and Anna) as second factor and five cultivation patterns [(pure chickpea), (25% L. iberica: 100% chickpea), (50% L. iberica: 100% chickpea), (75% L. iberica: 100% chickpea), and pure L. iberica cultivation (100% L. iberica). The highest leaf chlorophyll a and b contents were obtained in winter with intercropping of %100 Nosrat chickpea + %50 L. iberica and planting ratio (%100 chickpea +% 25 L. iberica), respectively. The highest leaf carotenoid content was obtained in spring with planting ratio of %100 Saral chickpea + %75 L. iberica. The highest water use efficiency was obtained in winter, in the Nosrat variety, and in pure cultivation. The land equivalent ratio in all intercropping patterns was more than one, which showed the superiority of L. iberica and chickpea intercropping compared to pure cropping.

Spreading hedgeparsley is a weed of wheat fields which thier seed bank is increasing in Kermanshah province. The aim of this study was to investigate the effect of time, burial depth, and seed shape in the field. This study was conducted as a factorial experiment in a completely randomized design with 3 replications. Both hairy and non-hairy forms of spreading hedgeparsley seeds were placed in different depths of storage (control), zero (soil surface), 5, 10, 20, and 40 cm of soil, and then seeds digged out from soil at 3, 6, 9, and 12 months burial time. The results showed that the effect of time, burial depth, and seed shape treatments on germination was significant in the field. The highest percentage of spreading hedgeparsley seed germination was observed in the first 3 months after burial. In general, the percentage of seed germination decreased by time. At a depth of 5 cm in the soil due to the favorable environmental conditions such as temperature, light and oxygen, the highest germination percentage was observed. Seed germination percentage decreased with increasing depth. The percentage of germination of spreading hedgeparsley seeds was higher than that of spinyseeds due to the level of contact of seeds with light, temperature and humidity.

In order to investigate the changes in weed flora in the irrigated wheat fields of Isfahan county over a 15-year period (from 2019 to 2004), a systematic sampling of weeds was conducted in 100 farms with W pattern during wheat tillering to stem elongation stages. In 2004, the dominant weed species was winter wild oat (Avena ludoviciana) with a abundance index of 76.1; however, in 2019 three weed species, including winter wild oat, wild barley (Hordeum spontaneum), and littleseed canarygrass (Phalaris minor) were recognized as the dominant species with abundance indices of 70.1, 42.3, and 28.6, respectively. In 2004, the dominant broadleaf weed species were lambsquarters (Chenopodium album) with a dominance index of 67.9 and prostrate knotweed (Polygonum aviculare) with a dominance index of 31.96. However, in 2019, the highest dominance indices were observed in lambsquarters, prostrate knotweed, and Flixweed (Descurainia Sophia) with abundance indices of 78.4, 38.5, and 39.04, respectively. The correlation between weed distribution and soil factors (nitrogen, phosphorus, potassium, soil texture, and electrical conductivity), crop rotation, and herbicides was examined using canonical correspondence analysis (CCA). Littleseed canarygrass, wild barley, field brome (Bromus commutatus), licorice (Glycyrrhiza glabra), hoary cress (Cardaria draba), and yellow sweet clover (Melilotus officinalis) showed the highest correlation with soil nitrogen levels.