CROP PHYSIOLOGY
Year:2020 | Volume:12 | Issue:1 (45)|Papers Count:8

Mineral arsenic (As) is a pervasive peripheral carcinogen substance and consuming foods and drinking water contaminated with this element can have consequences for human and animals health. Arsenic accumulates in surface soils in response to the weathering of rocks, cliffs, as well as human activities. Arsenic-exposed plants exhibit cytotoxic effects, such as growth retardation, cellular dysfunction and metabolism dysfunction. In the present research, effect of different concentrations of sodium arsenate solution (zero, 5, 10, 15 and 20 milligram per liter) was investigated on germination, growth and some physiological parameters of alfalfa in hydroponic medium. The results indicated that by increasing the concentration of arsenate, the percentage and rate of seeds germination, growth, concentration of photosynthetic pigments and concentration of root carbohydrates and aerial parts of alfalfa plants decreased. Also, the assessment of tension and growth indices (tolerance index, toxicity percentage, seedling vigor index and relative growth rate) confirmed these negative effects. According to the obtained results, it seems that arsenate, especially in high concentrations, appears to disrupt photosynthesis system, metabolism and inhibition of growth and development in the alfalfa plant, by inducing toxicity in plant and interfering with metabolic processes and mineral uptake.

In order to investigate the effect of different sources of organic and chemical fertilizers on some physiological parameters of different rice cultivars in drought tension conditions, an experiment was conducted as split factorial in a randomized complete blocks design with three replications at research farm, located in Sari in 2016. Three levels of tension included drought tension at early tillering stage, drought tension at full heading stage and control (no tension) were considered as the main factor and four fertilizer sources of vermicompost, Azolla compost, humic acid and chemical fertilizer of N. P. K and two cultivars of Shiroudi and Tarom Mahali as factorial as the sub factor. The results showed that there was a statistically significant difference between Tarom Mahali and Shiroodi cultivars in terms of yield at drought tension levels and different fertilizer sources. The highest paddy yield for Shiroudi and Tarom Mahali cultivars (equals to 6577 and 3776 kilogram per hectare, respectively) was obtained under common irrigation conditions and with the application of tension, the rate of yields decreased, especially with the application of drought tension in the clustering stage, when the yield of Shiroodi and Tarom Mahali cultivars decreased by about 17. 6 and 2. 9 ercent, respectively. The application of humic acid, Azola compost and vermicompost resulted in 17. 3, 13. 7 and 8. 8 percent increase in grain yield for Shiroudi cultivar and 9. 7, 3. 8 and 2. 6 percent increase in yield for Tarom Mahali under drought tension at tillering stage, respectively, compared to N. P. K chemical fertilizer. The highest amount of total and reducing sugar (147. 3 and 4. 289 milligram per gram, respectively) was obtained under drought tension conditions at early tillering stage with using the humic acid for Shiroudi cultivar. Therefore, according to the results of the present research, the application of humic acid is suitable for achieving the maximum grain yield of studied rice cultivars under drought tension conditions.

Alkalinity of the soil is one of the main problems in some soils of Iran, which reduces the solubility and reduces the absorption of essential nutrients, including the iron element for the plant. Iron deficiency in plants reduces photosynthesis and reduces production. The present experiment, as a factorial, was conducted in the form of a statistical design of complete randomized blocks and in 3 replications. The first factor including six levels of iron nano oxide fertilizer 0, 0. 5, 1, 1. 5 and 2 gram per liter and ordinary iron oxide in the amount of 2 gram per liter and the second factor including three stages of foliar application (vegetative growth period, beginning of tubing and tuber filling). The results showed that the application of iron nano oxide at the rate of 2 gram per liter compared to control treatment increased the amount of lysine in the tuber by 55 percent, the amount of methionine in the tuber by 45 percent, the amount of calcium in the tuber by 18 percent and the tuber yield by 7 percent. While the amount of phosphorus in the tuber was reduced by 34 percent with the application of 2 gram per liter of iron nano oxide. Foliar application of iron nano oxide significantly increased the amounts of methionine, potassium, and tuber yield at the time of tuber filling and beginning of tubing compared to the time of vegetative growth and the highest tuber methionine percentage with 0. 34 percent, the most potassium content of tuber with 2. 2 percent and the most tuber yield with 40 tons per hectare was acquired due to foliar application during tuber filling period. The percentage of protein, starch, and iron in the tuber increased with increasing the concentration of foliar application of iron nano oxide to concentrations of 1. 5 and 2 gram per liter and in all levels of iron nano oxide, foliar application of fertilizer also increased the amounts of protein, starch and iron during the tuber filing. According to the results, since there was no significant difference among the iron nano oxide by concentrations of 1, 1. 5 and 2 grams per liter in all studied traits, therefore, foliar application of iron nano oxide at a concentration of 1 gram per liter at the stage of tuber filling, which is more economical, is recommended.

In order to investigate the effect of water deficit tension on different growth stages on yield, yield components and produced grain quality of sorghum seeds cultivars, an experiments was performed as split plots based on randomized complete blocks design with four replications in Isfahan Ghiam Cultivation and Cattle Farm Company in 2017. The main factor including irrigation cut at four levels (irrigation cut from the pollination stage onwards, irrigation cut from the milking stage onwards, irrigation cut from the paste stage onwards and normal irrigation (control)) and sub-factor including three cultivars of seed sorghum (Sepideh, Kimia and Payam). The results showed that plant height traits, panicle length, one-thousand grain weight, panicle weight, grain weight in panicle, grain yield, protein percentage, sugar, starch and seed fat were affected by irrigation cut at different stages of growth. There was also a significant difference between different cultivars based on height traits, number of claws per plant and length of panicle. The results of the mean comparison showed that water deficit tension reduced grain yield and in terms of water cut-off tension before pollination compared to control caused 63. 95 percent of yield loss and in terms of irrigation cut in milking stage compared to control, 34. 4 percent of yield loss. While by cutting off the water in the paste stage, the yield increased by 2. 2 percent compared to the control. In general, the highest grain yield, one thousand grain weight and panicle weight were obtained in Kimia cultivar, which could represent a more tolerant cultivar to water deficit tension.

Water deficit is one of the most important environment tensions that reduce plant growth. The present experiment was conducted based on split plots based on complete randomized blocks design with three replications during 2019 cropping year at Moghan Agricultural Research Station. Two levels of irrigations as regular irrigation and irrigation cut in the seedling stage (irrigation cut applied during 21 days after plant germination) in the main plots and 11 maize hybrids in the sub-plots were compared. The results indicated that water deficit tension reduced plant height, dry weight, chlorophyll content and water related content in all maize hybrids. The amount of malondialdehyde increased under water deficit tension. However, water deficit tension did not have a significant effect on total polyphenols and hydrogen peroxide. Analysis of electrophoresis activity of antioxidant enzymes on polyacrylamide gel eight percent showed that two and one isoforms for peroxidase and catalase, respectively, in the studied corn hybrids, was observed. Water deficit tension significantly increased the activity of peroxidase and catalase isoforms. It can be concluded that the corn plant reduces the effect of water deficit tension by increasing the activity of the antioxidant and photosynthetic defense system. Based on the obtained results KLM77021 / 4-1-2-1-2-2-4-1 × K47/3 hybrid was identified as the hybrid tolerated to water deficit, compared to the studied corn hybrids.

In order to investigate the effect of nitrogen management on morphophysiological traits, yield and yield components of corn hybrids, the present experiment was carried out in a split plots arrangement in a randomized complete blocks design with three replications in a field located in Ahvaz city during the crop year 2016-2017. Experimental treatments consisted of nitrogen fertilizer management at three levels of 100 percent urea, 100 percent Nitrokara and 50 percent urea and 50 percent Nitrokara in main plots and different maize hybrids at three levels including Karon, Mobin and Single Cross 704 in sub plots. The results showed that nitrogen consumption management had a significant effect on plant height, ear length, yield, seed number per row, one-thousand grain weight and chlorophyll index and nitrogen consumption efficiency. Also, the studied hybrid type was significantly different in plant height, yield and yield components and nitrogen consumption efficiency. Among the investigated hybrids, Single Cross 704 was superior to other investigated hybrids, so that in terms of plant height, grain yield, number of seeds per row, weight of one thousand seeds and efficiency of nitrogen consumption was allocated the highest rate. In examining the interaction effect of nitrogen consumption management and corn hybrids, grain yield was significant at one percent probability level. The highest grain yield with an average of 6. 3 tons per hectare was related to 50 percent urea treatment and 50 percent Nitrokara and Single Cross 704 cultivar. Regarding the results, it seems that the combination of chemical fertilizer with bio fertilizer could increase the yield on hybrid Single Cross 704 and Mobin hybrid had less fertility.

Saravan is one of the arid regions of the country, so cultivating plants compatible with these areas can be effective in improving the province's agriculture. One of the most recently considered plants in the country is quinoa, which is resistant to adverse environmental conditions. Therefore, the present experiment was conducted with the aim of investigating the different levels of irrigation and foliar application with zinc sulfate and manganese in March 2019 in research field of Saravan Higher Education Complex as split plot in a randomized complete blocks design with three replications. Experimental treatments consisted of three levels of irrigation (50, 80 and 110 millimeter evaporation from Class A evaporation pan) in main plot and foliar application with zinc sulfate (three per thousand), manganese sulfate (three per thousand) and no foliar application in sub-plot. Results showed that the interaction effects of irrigation and foliar application were significant on plant height, leaf number, flower number, chlorophyll meter and one-thousand grain weight. In all irrigation treatments, foliar application with zinc sulfate was superior to manganese sulfate and non-foliar application. The highest grain yield was observed in 50, 80 and 110 millimeter evaporation from evaporation pan, respectively. Light tension treatment compared to mild tension was 24 percent and of high tension was 3. 4 times more than grain yield. The highest grain yield was observed in zinc sulfate foliar application treatment, which had 26 percent higher grain yield than non-foliar application treatment. Correlation interaction results showed that grain yield had the highest correlation with biomass, leaf dry weight and leaf number. Generally, foliar application with zinc sulfate can be used as an agronomic solution to increase yield of quinoain in Saravan climatic conditions.

In order to investigate the effect of agrophysiologic traits of bread wheat cultivars to planting date, the present research was conducted on the basis of split plots experiment based on randomized complete blocks design with three replication during 2012-2013 at the research farm of Khuzestan Agriculture and Natural Resources Research Station. Three planting date mid-October, midNovember and mid-December were considered as the main plots and three spring wheat cultivars (Chamran, Chamran2 and Aflak) as sub plots. The results analysis of variance revealed that the effect of planting date, cultivar and interaction effect of treatments on all studied traits was significant at one percent probability level. The highest grain yield was allocated to mid-November planting date with chamran2 cultivar (545 gram per square meter) and the lowest one to mid-December with Aflak cultivar (273 gram per square meter). The decrease in grain yield in mid-November planting date was due to a significant decrease in spike per unit area and average seed weight. Comparison between different wheat cultivars showed that there was an inverse relationship between rate of grain filling period and duration of it, so by changing planting date from mid-October to mid-December, grain filling rate from 1. 51 to 0. 98 milligram per day, grain filling period from 48 to 33 days, one thousand grain weight from 41 to 28 gram and finally seed yield decreased from 467 to 299 gram per meter square. Generally, Chamran2 cultivar had the higher number of days to physiological maturity, seed yield and yield components, harvest index and grain filling rate in compared to other cultivars, so in the optimal planting date of mid-November can recommended to producers in the studied region.