CROP PHYSIOLOGY
Year:2020 | Volume:12 | Issue:2 (46)|Papers Count:8

Sesame is one of the oldest crops in the world, due to its high oil content, is one of the most important oilseed plants in arid and semi-arid regional. This experiment was conducted in the form of statistical design in randomized complete blocks with split plots-factorial with three levels of moisture levels 100, 75 and 50% of sesame water requirement in the main plots application of calcium nitrate at three levels (0, 0. 5 and 10 Mm) and putrescine at two levels (0. 5 Mm and water spraying solution) in sub-plots with three replications at the Birjand University of Agriculture Research Farm was conducted in 2017. The result showed that the interaction of moisture levels, calcium nitrate, and putrescine were significant (p <0. 05) for relative water content, ion leakage, osmotic potential, grain yield, oil yield and protein percentage. Decreased humidity levels of 50% water requirement led to a decrease in relative water content, osmotic potential, grain yield, oil yield and oil percentage, but ion leakage and grain protein percentage increased under conditions of decreasing moisture levels. Among the sprayed compounds, traits such as relative content, grain yield, oil yield and protein percentage had a higher mean than other treatments. The highest grain yield (1373/93 Kg/ha) was obtained at moisture levels of 100% water requirement with the use of putrescine and 10 Mm of calcium nitrate. Also dual interaction of moisture levels calcium nitrate in calcium nitrate and moisture levels putrescine were significant (p <0. 05) for grain oil percentage.

In order to evaluate the effect of late-season heat stress on grain yield and yield components of wheat under nitrogen and zinc application, a split-split plot experiment based on RCBD in four replications was carried out in an experimental field of Khuzestan agriculture and natural resources university during 2017-18 growing season. Experimental factor was three planting date including 22 November (appropriate planting date), 11 December (late planting date) and 31 December (very late planting date) on the main plot, nitrogen in four levels (0. 0, 75, 150 and 225 kg ha ) in subplots and zinc in three levels (0. 0, 10 and 20 kg ha-1 ) in subplots. The grain yield of wheat was reduced by 40% with heat stress. Grain yield of wheat was affected more by grain number (reduction of grain number per unit area and grain weight was 38% and 20%, respectively). Nitrogen diminished the effect of heat stress on grain yield of wheat through increasing the grain numberbecause the increase if nitrogen application resulted in a 3. 27% reduction of grain weight. Zinc application reduced the effect of heat stress on grain yield through an increase of about 24% by weight of grain. Since the effect of lateseason heat stress on the reduction of grain yield of wheat (39% reduction) was more than biological yield (31%), harvest index of wheat was reduced 18% by heat stress. In general, the application of 150 kg ha-1-1 ha Zn can reduce the enative effects of late-season heat stress on grain yield of wheat.

In order to investigate the effect of zinc nano oxide on yield and some physiological characteristics of wheat under drought stress conditions, a factorial experiment was a three-factor factor conducted in a completely randomized design with three replications in University of Mohaghegh Ardebili in 2018. Factors studied i include the first factor of drought stress at three levels (35%, 60% and field capacity and control), the second factor of wheat cultivars (Mihan, Heidari, Sysons and Gasgogen) and the third factor includes ZnO spraying in three levels (no application of ZnO, 0. 5 and 1 g/l ). Foliar application of ZnO was performed in three-leaf stage and three day later drought stress for one week. ZnO foliar application increased the amount of photosynthetic pigments and leaf chlorophyll index, FV / FM, plant length, spike number and grain weight. Drought stress decreased chlorophyll index (3. 73%), F0 (60. 79%), Fv (11. 18%), Fv / Fm (2. 68%), mean plant height (15. 93%), Total dry weight (16. 27%), dry weight (46. 18%) and root fresh (8. 32%) as well as grain yield (15. 95% of grain number and 11. 93% of grain weight). Also, ZnO foliar application and irrigation under control conditions improved chlorophyll index (151. 01%) and photosystem II fluorescence during growing season (78. 62%) and increased wheat grain yield under (338. 38% of grain number and 361. 62% of grain weight) dehydrated conditions. Among the studied cultivars, the highest amount of F0 (235. 5) and Fm (756/44) belonged to Meihan cultivar and the least amount of (204/944), F0 (34. 0), Fm (362. 28) and FV / FM (0. 4585) belonged to Heidari cultivar. Under drought stress, the weight of one thousand grains in Heydari cultivars (155. 35%) and Gasgogen (32. 60%) decreased compared to control conditions. Among cultivars, Mihan was more tolerant to drought stress. In terms of grain yield under normal conditions, Heydari genotype was recognized as the best genotype.

Water shortage, nitrogen fertilizer and zinc deficiency are important factors affecting quantitative and qualitative of wheat. This study was conducted as a split-factorial experiment based on randomized complete block design with four replications in 2017-18 with nitrogen in three levels 40, 80, and 160 kg/ha and application and non-application of zinc under normal irrigation, irrigation up to complete flowering and stem elongation were applied. Irrigation up to stem elongation resulted in a significant decrease in 1000-grain weight (11. 24%) compared to the control treatment. Foliar application of zinc fertilizer showed a 4. 24% increase in 1000-grain weight compared to the control treatment. The most prominent result was the simultaneous application of 80 kg N/ha and Zn fertilizer under irrigation up to stem elongation, which resulted in 43. 6% increase in grain yield compared to irrigation up to flowering. Irrigation up to stem elongation compared to normal irrigation resulted in a 28% increase in the average grain protein. The application of 40 and 80 kg N/ha compared to the treatment of 160 kg/ha led to more adsorption of zinc in plant organs. In general, the co-application of zinc and nitrogen fertilizers (80 kg/ha) under irrigation up to stem elongation treatment led to the modification of the negative effects of water shortage. The co-application of zinc and nitrogen fertilizer (80 kg/ha) under irrigation up to stem elongation conditions is recommended for Mahabad region of Isfahan province.

Legumes are the largest source of vegetable protein which 18. 5% of human protein being supplied by legumes. Molecular nitrogen fixation (N2) by legumes in addition to resolving their needs is very useful for crops that fall in rotation next year. Molybdenum is involved in the activity of enzymes that fix nitrogen. Therefore, in order to investigation effect of molybdenum and nitrogen on yield of two chickpea cultivars, a two-year experiment was performed as factorial split plot based on randomized complete block design at Dryland Agriculture Research Institute, Kermanshah, Iran. The main plots were included two chickpea cultivars (Arman and Adel) and sub plots were consisted of different levels of molybdenum (Mo1 =0, Mo2 =1 and Mo3 =2 Kg. ha ) as Ammonium molybdate from and nitrogen levels (N1=0, N2=25 and N3=50 kg. ha-1 ) as urea form which conducted in three replications. The results showed that the effect of cultivar on grain yield, biological yield, straw yield, number of seeds per pod and number of pods per plant was significant (1% Probe). The average yield of Adel cultivar was 924. 5 kg. ha-1-1 . The effect of different Amounts of molybdenum on number of pods per plant, leaf nitrogen percentage, number of seeds per pod and nodule weight was significant. In all cases, the highest amount was obtained from 2 Kg. ha that was higher than Arman cultivar with 847. 1 Kg. ha-1 of Ammonium molybdate source. The highest grain yield was obtained by application of 50 kg. ha-1 urea as nitrogen source and 2 Kg. ha-1 ) have not significant difference with the treatment of 25 Kg. ha-1 Ammonium molybdate (1135. 8 kg. ha-1-1 urea and 2 Kg. ha-1 Ammonium molybdate(1088. 6 Kg. ha-1 Ammonium molybdate is recommended to chickpea under rainfed cultivation.

In order to determine the susceptible and tolerant lines of sunflower to drought tension, an experiment as a randomized complete blocks design with three replications was conducted at Karaj Seeds Oil Research Institute. In this investigation, 12 different sunflower liens have been screened for the characteristics related to drought tolerance and two susceptible and tolerant lines wereidentified. So, initially, sunflower lines were cultivated in two separate experiments under normal irrigation and drought tension conditions in a randomized complete blocks design with three replications. Drought tension was carried out through irrigation cut in step 2 to 8 leaves. The investigated traits included yield characteristics and yield components of sunflower, such as one-thousand grain weight, number of seeds per head, oil percentage, grain yield and oil yield. The traits were significantly different except for oil percentage at a probability level of 1 percent. After investigating the studied factors and analyzing the data, the obtained results were determined by examining the percentage change in the studied traits, calculating the tension indices (drought tolerance, drought susceptibility indices) and drawing a dendrogram derived from cluster analysis of cultivars. In conditions of application of tension, RGK46 and RGK41 had the highest and lowest one-thous and weight, respectively, among the existing lines. Also, about the number of seeds per head, RGK26 and RGK44 had the highest and lowest number of seeds per head, respectively. In terms of grain yield RGK26 and RGK41 had the highest and lowest grain yield per plant, as well. Combining these factors and comparing the traits among cultivars, we can identify BGK221 line as the sensitive line and the RGK46 line as tolerant from the 12 lines studied. Also, the number of seeds per head with the weight of one-thousand grain weight and oil yield is positively correlated. Also, grain yield was positively correlated with STI index.

Due to the great importance of drought stress and its effect on physiological and biochemical traits and reducing wheat grain yield in arid and semi-arid areas (such as most areas of Iran), this research was conducted to evaluate the effect of cut of irrigation on yield and some physiological traits of different growth type of wheat. To this end, a split plot experiment based on randomized complete block design with three replications was used in Kermanshah province in the 2012-2013 crop year. Moisture regimes were applied in the main plots at two levels include: control (irrigation treatments at all stages of growth based on water requirements of wheat) and cut of irrigation (stop watering based on Amber thermic curve). Different wheat cultivars (including: Alvand, Sivand, Zarin, Baz, Bahar, Shahryar, Norestar, Pishgam, Pishtaz, Kavir, Orume and Parsi) were used in sub-plots. Based on the results, in control treatment, Norestar had the lowest grain yield (1270 kg/ha), but other cultivars with an average of 4600 kg per hectare did not have significant difference in this regard. Cut of irrigation significantly reduced grain yield (40% in average) and Kavir and Shahriar 2100 and 2210 kg ha-1 had the highest reduction in grain yield. Cut of irrigation significantly reduced no of grain/spick, 1000 grain weight, soluble proteins, relative water content, and significantly increased activity of antioxidan enzymes such as: peroxidase, catalase and superoxide dismutase and osmotic potential of cells (greater than of 150%). No significant reduction in the content of photosynthetic pigments and leaf area under Cut of irrigation treatment at the end of the growing season can be associated with increasing in antioxidant activity and osmotic regulation of the studied cultivars.

Drought stress is one of the most important factors limiting the growth and development of crops. This experiment was conducted using a split-plot arrangement in randomized complete block design with 3 replications in research field of Islamic Azad University of Kaleibar, Iran in crop year 2017. In this experiment, the effect of three levels of drought stress after 60, 90 and 120 mm evaporation from Class A evaporation pan in the main plots and three levels of zero, 75 and 150 kg. ha in sub-plots on the physiological characteristics in wheat (Triticum aestivum cv. Mihan) the comparison was made. The results of analysis of variance showed that the interaction of drought stress and superabsorbent on stomatal conductanc, cell membrane stability, proline and leaf chlorophyll index was significant. The results of comparison the mean interaction between drought stress and superabsorbent showed that the maximum chlorophyll index 6. 70%, stomatal conductance 7. 45 molCo2.-1 and cell nomadic stability 48. 25% was evaporated by 75 kg / ha treatment of superabsorbent application at drought in 60 mm evaporation, respectively. Comparison of the average treatment showed that the highest transpiration rate 6. 10 μ mol H2O. m m-2. s-1, maximum photochemical efficiency of PSII. 894 and leaf internal Co2 556. 02 molCo2.-2. s-1, photosynthesis rate 28. 23 molCo2. m-2. s-1 was related to treatment 60 mm evaporation and the highest amount of soluble carbohoids 121. 31 μ g glucose. g fw was related to treatment 120 mm evaporation. The use of superabsorbents significantly increased physiological traits such as relative water content, photosynthesis rate, stomatal conductance, transpiration rate, maximal photochemical efficiency of photosystem II, and chlorophyll index. Therefore, irrigation of 60 mm evaporation and consumption of 75 kg. ha m-2. s-1 of superabsorbent as the best treatment is recommended to achieve the maximum amount of wheat physiological traits.