نشریه زراعت دیم ایران
سال یازدهم شماره 1 (بهار و تابستان 1401)

To study effects of crop residues and rotation levels on grain yield, chlorophyll content, activities of superoxide dismutase, Cu/Zn-SOD isozymes, Mn-SOD isozymes, Fe-SOD isozymes, glutathione reductase, ascorbate peroxidase, catalase, amount of hydrogen peroxide and malondialdehyde in five dryland wheat cultivars, Experimental treatments were: a) two wheat-wheat and forage-wheat rotations in the main plots, b) three levels of crop residues including non-use, 2 and 4 tons of residues in subplots, c) 5 wheat cultivars including Sadra, Hashtrood, Baran, Varan and Ohadi in sub-sub plots. Combined analysis of variance showed that the effects of rotation, crop residue values and cultivars were significant on most of the studied traits. The highest grain yield (1809.9 Kg/ha) was obtained from Varan cv. at 2 T/ha forage crop residue. The highest chlorophyll a, chlorophyll b and carotenoid were observed in 4 T/ha crop residues with forage-wheat rotation in Varan cultivar. Also, the lowest content of hydrogen peroxide and lipid peroxidation were recorded in 4 and 2 T/ha of crop residues in forage-wheat and Varan cultivars, respectively. Due to the importance of using conservation agricultural pattern in dry lands of Iran, in order to optimize the productivity of this model, in this study, maintaining plant residues of 2 tons per hectare with fodder-wheat rotation in rainfed conditions in Varan cultivars as the best treatment in terms of reduction the adverse effects of drought stress on the cell surface and maintaining the desired level of photosynthetic activity and thus the production of higher grain yield were known.

In order to evaluate the energy consumption efficiency in the chickpea production system, a field study was conducted in Ayvangharb, Ilam province, Iran during the 2019-2020 growing season and the required agricultural information in all stages of planting, growing and harvesting was collected by filling out a questionnaire and face-to-face interviews with 240 farmers. The results showed that the highest amount of input energy were diesel fuel, chemical fertilizers, seed and cultivation, chemical fertilizers, fuel and seed in mechanized and traditional cultivation, respectively. Energy ratio, energy efficiency, energy intensity and net energy were determined 2.83, 0.27 Kg/ MJ, 3.6 MJ/ Kg and 12272.46 MJ/ ha in mechanized cultivation and 2.41, 0.23 Kg/ MJ, 4.2 MJ/ Kg and 9608.52 MJ/ ha in traditional cultivation ,respectively. The share of direct, indirect, renewable and non-renewable energy was 47, 53, 20, 80% in mechanized cultivation and 38, 62, 31, 69% of total energy consumption in traditional cultivation, respectively. Questionnaire statistics were analyzed by modeling with DEA solver and it was found that fungicides, phosphate fertilizer and pesticides inputs are the best inputs affecting grain yield and straw yield in mechanized and traditional crops. However, these inputs were less efficient in traditional cultivation than in mechanized cultivation. Also, the analysis of indicators showed that the efficiency of mechanized cultivation is higher than traditional cultivation.

This research was conducted in three places in Kermanshah province in 2017-18 cropping season in order to study effect of different herbicides on weeds in chickpea varieties. Experiment layout was strip split plot based on RCBD with two replications. Horizontal factor was included weed control treatments (1. Pendimethalin 4 lit.ha-1 Pre-Planting, 2. Pursuit 0.5 lit.ha-1PP, 3. Sencor 1 lit.ha-1 PP, 4. flumetsulam 20 gr.ha-1 PP, 5. Merlin flex 0.2 lit.ha-1 PP, 6. Merlin flex 0.2 lit.ha-1 Pre-Emergence, 7. Oxyflurofen 0.2 lit.ha-1, 8. Pendimethalin 2 lit.ha-1 PP , 9. No control, and 10. Hand weeding) and vertical factor was included chickpea varieties (1. Azad, 2. Ozbek1, 3. Ozbek6, 4. Akso, 5. Azkan, 6. Adel and 7. Mansour) in Sarpol site, and (1.Iraqi, 2. Ozbek6, 3. Azkan, 4. Ana, 5. Saral, 6. Adel, and 7.Mansour) varieties in Sonqor. Results of ANOVA for grain yield showed significant effect of weed control and variety in Sonqor and Sarpol zahab. In Sonqor grin yield of hand weeding was the highest and merlinflex , pendimethalin and persuit were in next class and higher than no control check. Ana and Adel varieties had the highest yield. In Sarpol zahab, highest yield produced by hand weeding, pendimethalin and merlinflex, respectively. In term of varieties Adel had highest grain yield and Akso and Mansour were located in second class. In Sarab nilofar because of sever hailstone in May 2018 the experiment destroyed.

In order to investigate the effect of nitrogen fertilizer levels and planting density on the yield and yield components wheat cultivar of Qabus, a study was conducted in the two cropping years of 2018-19 and 2019-2020 in the farm of Gonbad. The experiment was a split plot in a randomized complete block design with three replications. Nitrogen fertilizer treatments included zero, 100, 200 and 300 kg / ha of urea source were in main plots and planting density levels included 150, 225, 300, 375, 450 and 525 seeds per square meter were in subplots. The results of analysis of variance showed that in both years of experiment, grain yield, number of spikes per square meter and number of seeds per spike were affected by different levels of nitrogen fertilizer, different levels of plant planting density and fertilizer interaction at planting density at 1% but the interaction of grain weight per spike in both years of the experiment was not affected by fertilizer levels and planting density levels. The results of comparing the mean interaction of treatments showed that the combination of fertilizer levels of 300 kg / ha and density of 300 plants per square meter in the first year of the experiment with grain yield of 4957 kg / ha and fertilizer levels of 200 kg / ha and density of 375 plants per square meter in The second year of experiment with grain yield of 4408 kg / ha had the highest value

 Conservation agriculture reduces soil erosion and increases long-term yield by increasing organic matter. Experimental was conducted in order to evaluate the tillage system (T) and crop straw rates (S) effects on seed yield of chickpea Adel cultivar under rainfed conditions in the wheat-chickpea rotation. This experiment was conducted in a split plot based on a randomized complete block design with three replications in three cropping seasons 2017-20 in the dryland agricultural research sub-institute. The tillage system was in the main plots including conventional tillage (CT) (moldboard plow + disk harrow), minimum tillage (MT) (chisel + disk) and no-tillage (NT) (direct drilling), and crop straw rates were in sub-plots including no-straw (S1), 30-50 (S2) and 50-70% (S3) straw. Results revealed that the main effect of T was significant for the grain yield (P<0.05). The highest grain yield (1034 kg. ha-1) was obtained from MT which indicated an increase of 10 and 24% compared to CT (936.7 kg ha-1) and NT (833.7kg ha-1), respectively. The effect of S was significant for plant height (P<0.01), and grain yield, straw yield and biological yield (P<0.05). The highest grain yield was obtained from S1 with 990.6 kg ha-1, which was not significantly different from S2 with 953 kg ha-1. The highest grain yield and biological yield were obtained from MT × S2 with 1136 and 2433 kg ha-1, respectively. Therefore minimum tillage with 30-50% crop residues in the field could be used to improve yield productivity and stability of chickpea under rainfed conditions.

In order to evaluate the impact of salicylic acid on yield and yield component of Indian mustard under irrigation and non- irrigation and different doses of clopyralid, a field experiments was laid out in randomized complete block design with split-split plot arrangements having three replications were conducted at the research farm of East Azerbaijan Agricultural Research Center in 2019 and 2020. Irrigation levels (non-irrigation and supplementary irrigation) were assigned to main plots, salicylic acid levels (control without salicylic acid, priming of Indian mustard seeds with salicylic acid and foliar application with salicylic acid) were assigned to sub plots and different levels of clopyralid ((0 (weed free control), 0 (weed infested control), 0.4, 0.8 and 1.6 L.ha-1)) were allocated to sub-sub plots. The results showed that the application of clopyralid 0.4 L.ha-1 in non-irrigation condition resulted in highest number of pods per plant, number of seeds per pod, 1000 grains weight, and grain yield, and in this regard there was not statistically significant difference with weed free control. Maximum reduction in the number of pods per plant, number of seeds per pod, 1000 grains weight, and grain yield of this crop is related to treated plants with clopyralid 1.6 L.ha-1 and weed infested control under supplementary irrigation condition. Seed pretreatment with salicylic acid reduced the negative effects of clopyralid herbicide on Indian mustard plants grown from these seeds and increased the number of pods per plant, number of seeds per pod, 1000 grains weight, biological yield, grain yield, and harvest index.

Change in plant physiological relationships especially in photosynthesis under drought stress can affect light absorption and the final yield of the crop. Improving the parameters related to photosynthesis in order to increase or decrease the loss of assimilation under drought stress is one of the ways of crop management. The effect of three growth hormones (3 indoleacetic acid [IAA], gibberellic acid [GA3] and 6 benzylaminopurine [6 BAP]) via control (distilled water) was evaluated at booting stage of two wheat cultivars (Rijaw and Azar 2). A factorial experiment using a randomized complete block design (RCBD) with three replications was setup at the Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran during 2014-15 and 2015-16. The results showed that 6-BAP and IAA produced the highest grain yield in the Rijaw cultivar with averages of 1800 and 1700 kg.ha-1, respectively. Also, the highest mean of specific leaf weight (86 mg.cm-2), photosynthesis rate (18.6 μmol CO2.m-2.s-1) and photosynthetic water use efficiency (667 μmol CO2.mol-1H2O) were related to the application of 6-BAP on Rijaw cultivar. The photosynthetic rate had a positive and significant correlation with specific leaf weight (R2= 0.92), photosynthetic pigments content(R2= 0.98) and mesophilic conductivity (R2= 96). Also, the Rijaw cultivar was superior to Azar-2 in all traits. In general, it can be concluded that the external application of various growth hormones in the critical stages of growth and development of wheat improves the photosynthetic capacity of the plant. This will reduce the final grain yield loss under drought stress conditions.