CROP PHYSIOLOGY
Year:2018 | Volume:10 | Issue:37 |Papers Count:9

In order to determine the relationship between yield and some of the agronomic traits and evaluate the effect of different levels of phosphorus fertilizer on studied traits of two hybrids of grain corn under drought tension conditions, a split-split plot experiment was conducted in a randomized complete blocks design with three replications. Drought tension was applied as the main factor in three levels including: full irrigation, tension at panicle emergence stage and tension at seed filling stage. Phosphorous fertilizer as sub-factor in three levels 0, 200 and 300 kilogram per hectare (control without fertilizer, 100 percent of fertilizer recommendation and 50 percent more than fertilizer recommendation, respectively) and hybrid as the sub-sub factor at two levels (SC704 and SC700) were considered. The effect of irrigation, fertilizer and hybrid on yield and many other traits was significant. The highest grain yield was obtained under full irrigation conditions and the lowest on tension conditions at seed filling stage. There was no significant difference between 700 and 704 hybrids at different levels of irrigation. The highest dry weight was obtained under full irrigation conditions. In this situation, there was no significant differences between using 200 and 300 kilogram per hectare phosphorus fertilizer and Single Cross SC700 as well as using 100 and 300 kilogram per hectare phosphorus fertilizer and Single Cross SC700. Both in normal irrigation and tension conditions, the highest correlation was observed between grain yield and harvest index. Based on stepwise regression and path analysis, both under normal irrigation and tension conditions, the traits of harvest index and dry weight had the most effect on grain yield and in selective programs can be effective for increasing production capacity. The highest dry weight was obtained from full irrigation treatments, consumption of 200 and 300 kilogram per hectare phosphorus fertilizer and hybrid SC700, as well as full irrigation, consumption 100 and 300 kilogram per hectare phosphorus fertilizer and hybrid SC704.

In order to investigate the effect of zinc sulfate fertilizer on quantitative and qualitative yield of Safflower under water deficit tension conditions, a research was conducted as factorial experiment based on a randomized complete blocks design in three replications in 2016. Experimental treatments consisting of three levels of water deficit tension, irrigation cut at vegetative phase (stem elongation), irrigation cut at reproductive phase ( flowering) and full irrigation(no water deficit tension), and the amount of zinc sulfate fertilizer in three levels, including the lack of fertilizer application(zero), 30 and 60 kilogram per hectare. The duration of application of water deficit tension in each stage of vegetative and reproductive processes was based on evaporation of 140 millimeters water from class A evaporation pan. The results showed that the simple effects of fertilizer and water deficit was significant on all of the traits and the effect of low-water interaction and the amounts of fertilizer on grain yield, one-thousand grain weight, seed oil percentage and chlorophyll content of safflower leaves was significant. As the highest and lowest seed yield (2954. 41 and 680. 75 kilogram per hectare), one-thousand grain weight (50. 52 and 22. 41 g), Oil percentage (28. 96 and 19. 85 percent) and chlorophyll content (62. 89 and 40. 15 spad) belonged to the combination of full irrigation treatment and consumption of 60 kilogram per hectare zinc sulfate fertilizer and combination treatment of no irrigation at reproductive stage and no fertilizer application, respectively. Fertilizer treatment of 60 kilogram per hectare had the maximum number of head (14. 08) and the number of seeds per heads (34. 36). In terms of water deficit tension, lowest number of heads per plant with 9. 63 was belonged to no irrigation treatment at vegetative stage and the lowest number of seeds in head with (11. 79) belonged to no irrigation treatment at the reproductive stage. In general, the use of zinc in the form of zinc sulfate fertilizer could mitigate the harmful effects of water deficit tension especially at the flowering stage in the investigated traits and improve growth conditions for plants and increases yield and yield components of safflower.

In order to investigate the genetic diversity, 20 genotypes of durum wheat were evaluated in a randomized complete blocks design with three replications in a research farm of Agricultural Campus, Razi University of Kermanshah, for the grain yield, physiological traits and activity of antioxidants enzymes in 2013-14 cropping year. The results showed that there was a significant difference between the cultivars for all traits except leaf water content at the probability level of one percent. Heritability, genetic enhancement and high genetic variance for the traits of grain yield and saturated water deficit was observed. Therefore, selection of genotypes based on these traits has high efficiency. Level of enzyme activity of superoxide dismutase and catalase enzyme activity were positively and significantly correlated with water stored in cut leaves. Totally, among the investigated genotypes, there was a significant difference between all the investigated traits, which indicates the optimal efficiency of the genotypes studied for corrective purposes.

A part of the sun's infrared light does not affect the plant photosynthesis reaction and mainly increases the plant temperature and transpiration and water consumption. Kaolin clay spraying was used as a reflector of sunlight and transpiration reducer in safflower plant. This experiment was carried out in a statistical randomized complete blocks design as split plots in three replications in the research field of Agricultural and Natural Resources Faculty of Islamic Azad University, Sanandaj Branch, in cropping year 2016-17. In the present experiment, irrigation cut off with four levels of irrigation including control (full irrigation at all stages of growth), irrigation cut off from stemming to the end of the growth season, irrigation cut off from flowering stage to the end of the growth season, irrigation cut off from the grain filling stage to the end of the growing season in the main plots and foliar application of kaolin clay including: foliar application by distilled water (control), foliar application with kaolin clay 2. 5 and 5 percent, were compared in sub plots. The results showed that the effect of tension on leaf number, head weights, grain yield, biological yield, harvest index, oil yield and protein yield was significant at 1 percent level. The maximum seed yield was achieved in full irrigation or control treatment with the amount of 1084. 32 kilogram per hectare and the treatment of irrigation cut off in stemming, flowering and seed filling stages showed reduction by the amounts of 44. 39, 31. 42 and 3. 2 percent in arrangement, in comparison with control. In this experiment, the effect of kaolin clay on leaf weight, head weight, one-thousand seed weight, harvest index, protein percent and yield at 1 percent level and on the traits of seed yield and oil percent at 5 percent level, was significant. Foliar application of kaolin 2. 5 and 5 percent due to increased grain yield was recommended to the amounts of 23. 73 and 5. 49 percent, respectively, compared to control.

Considering the importance of soybean and the effect of water deficit in arid and semi-arid regions on the reduction of the plant yield, this research was carried out in order to investigate the physiological and biochemical responses of different soybeans cultivars in the face of water deficit tension in different stages of vegetative and reproductive growth. A factorial experiment was conducted in a randomized complete blocks design with four replications at the Agricultural and Natural Resources Campus of Razi University of Kermanshah in 2012-2013. The investigated treatments were included: water regime (1-control, 2-water deficit tension from vegetative stage and 3-water deficit tension from reproductive stage until maturity) and different soybean cultivars (including: Williams, L17, M9, M7 and Zan). The results indicated that application of water deficit tension at vegetative and reproductive stage of growth with the exception of M7 cultivar, compared to control treatment, had a significant effect on grain yield of other cultivars. The highest reduction in grain yield at both levels of water deficit tension was related to Williams cultivar with 57 and 51 percent reduction, respectively. Application of water deficit tension at vegetative and reproductive stage of growth significantly reduced the content of chlorophyll a and b pigments, maximum photochemical efficiency of photosystem II, soluble proteins and relative water content of leaf and increased carotenoids, soluble sugars and proline content and stomatal resistance value and activity rate of antioxidant enzymes catalase, peroxidase and superoxide dismutase of leaves. Among the investigated traits, stomatal resistance value and proline content of leaves under water deficit tension conditions had the highest increase compared to control conditions. Among the antioxidant enzymes, peroxidase had the highest rate of activity in both moisture conditions in the investigated cultivars.

This experiment was conducted to investigate the effect of nitrogen on yield and nitrogen use efficiency of corn genotypes under the conditions of competition with weeds and as split plots in a randomized complete blocks design with four replications. In the main plots, three amounts of nitrogen fertilizer (90, 180 and 260 kilogram net nitrogen per hectare from source of urea (46 percent nitrogen) and without fertilizer, and in the subplots of four corn hybrids SC. 704, DKC6589, Mobin and SC. 640 were compared. Each sub plot was hypothetically divided into two weed free and with weed equal parts. The results showed that nitrogen application efficiency in plots with weeds was significantly decreased. The presence of weeds caused the average weight of 100 seeds, grain yield and biological yield to be reduced by 5. 3, 21. 7 and 24 percent, respectively, in comparison to weeding conditions. The use of nitrogen fertilizer up to 180 kilogram per hectare increased the grain yield of all genotypes under conditions of competition with weed. In conditions of competition, the performance of all genotypes with the exception of DKC6589 line decreased at 260 kilogram nitrogen per hectare treatment as compared to 180 kilogram nitrogen per hectare treatments. So that in the weed presence conditions, the average corn yield increased by 50 and 30 percent in 180 and 260 kilogram nitrogen per hectare in fertilizer treatments, respectively. The highest grain yield in both conditions of competition and weeding of weeds (908 and 1222 kilogram per hectare, respectively) was allocated to DKC6589 line. Increasing nitrogen rate increased the mean plant height of corn genotypes in both competition and weeding conditions. Plant height, ear height from the surface of ground, and the number of leaves of DKC6589 line was significantly higher than other corn genotypes. Plant height, ear altitude from the ground and leaf number of DKC6589 were significantly higher than other hybrids.

In order to optimize the conditions and also increase the production of potato mini tuber in Agria cultivar, the effects of various amounts of nitrogen and acidity of nutrient solution in two separate experiments in 2013 in a completely randomized design with three replications in a hydroponic environment in a research greenhouse of the Faculty of Agriculture of Ferdowsi University of Mashhad was carried out. In one experiment, different levels of nitrogen (zero milligrams + Hoagland solution (control), 50 milligrams + Hoagland solution and 100 milligrams + Hoagland solution) was in the form of ammonium nitrate and in another experiment, Hoagland protein solution acidity was at three levels (3, 4 and 5/6). Three times after seedlings transplants to planting bed (30. 35 and 40 days after planting), the acidity treatments were applied for 10 hours on the plants and after that leaching was arranged. The results indicated that increasing the amount of nitrogen caused an increase and reduction of acidity caused reduction of photosynthesis, transpiration and chlorophyll a and b concentrations compared with the control. The increase in nitrogen from zero to 100 milligram per liter and the temporary reduction of acidity from 5. 6 to three increased the mean weight, diameter and number of micro tubers. an increase in mean weight, diameter and number of mini tubers. Increasing nitrogen content increased and reducing the acidity of the nutrient solution reduced leaf area and dry weight of the shoot. The number of micro tubers did not differ significantly with increasing nitrogen levels from 50 to 100 milligram, which indicates that increasing nitrogen consumption increases the number of tubers to a certain extent, but since then, does not significantly change the yield and may even have negative effects In general, it seems that consumption management and the application of appropriate amount of nitrogen fertilizer and short-term reduction of dietary acidity of acid solution can frequently play an important role in increasing the production of micro tubers and yield in this plant.

Considering the increasing environmental pollution, especially heavy metals, it is necessary to find new and inexpensive methods to clean up contaminated soils and waters. The lead is one of the most important environmental pollutants which disturbed nutrient uptake by plant. In order to investigate the potential of some biological agents in phytoremediation of lead and the absorption of nutrients by annual alfalfa in lead-contaminated soil, a factorial experiment was conducted based on completely randomized design with four replications. In the present experimental, the first factor was the heavy metal levels of lead containing lead concentrations (17. 5, 417. 5 and 817. 5 milligram/kilogram) and the second factor was the treatment combinations including the application and non-application of superabsorbent nano polymer, humic acid and bacteria. The results showed that increased lead concentration in the soil reduced the biomass and the relative water content of the leaves and toxic in the plant. But simultaneous use of bacteria and superabsorbent which caused the absorption of water and the application of humic acid, increased the plants efficiency in food intake. The highest amount of transfer factor was observed in treatment of application of 817. 5 milligram/kilogram lead and its lowest amount in the treatment of non-application of lead. Also, the use of humic acid and bacteria increased the transfer factor. The results of the present research showed that lead refining is possible by alfalfa plant, and humic acid as a chalking compound with superabsorbent and bacteria can well reduce the effects of lead toxicity in alfalfa.