CROP PHYSIOLOGY
Year:2020 | Volume:11 | Issue:4 (44)|Papers Count:16

This experiment was conducted to evaluate the effect of morphological and biochemical traits on dehydration tension tolerance in rice seedlings in a two-factorial factorial design in a completely randomized design with four replications in Seed Technology Laboratory of Shahed University of Tehran, in 2018. The first factor was different levels of water deficit tension including 0,-0. 5 and-1 Mega Pascal with polyethylene glycol 6000 and the second factor was different levels of priming including control (seeds without hydro prime), water pre-treatment (Hydro priming), potassium nitrate 0. 5 percent, Pseudomonas fluorescens (PF) strains, Bacillus subtilis (BS) bacteria strain and the combined effect of two bacteria PF × BS for 24 hours at 15º C. Considering the results of priming experiment and water deficit tension, there was a significant effect on the studied traits. Rice seeds had a high germination percentage, most of which was observed in potassium nitrate pre-treatment at two levels of control and-0. 5 Mega Pascal and the lowest of which was at 80 percent in simultaneous bacterial inoculation. Rice seeds had a high germination percentage, the highest of which was observed in the pre-treatment of potassium nitrate, at control and-0. 5 Mega Pascal levels and the lowest was at 80 percent in simultaneous bacterial inoculation. Reducing germination characteristics, growth parameters, relative humidity content happened with increasing tension, as well as enhancing photosynthetic pigmentation, anthocyanin content in Substile bacteria treatment with mean (12. 56) mg/g fresh weight of leaf relative to-1 Mega Pascal, proline in hydroperiming treatment with nontension by average (8. 85) mg/g fresh weight of leaves related to-1 Mega Pascal and also superoxide dismutase enzyme activity in potassium nitrate and fluorescence bacteria treatments 1342. 72 and 1355. 17 percent related to-1 Mega Pascal tension in increasing water deficit tension.

In order to determine the effect of foliage application of nutrients in different stages of growth of rice Sahel cultivar, an experiment was conducted during two years 2016-2017 in a randomized complete blocks design with four replications at the Rice Research Institute of Iran, located in Amol. The Experimental treatments included the foliage application of nutrients at a rate of one percent in the middle stage of tillering, maximum tillering, panicle initiation, maximum tillering + panicle initiation and all stages with the control treatment. Based on the obtained results, the foliage applications of nutrients in different stages of vegetative and reproductive growth had a significant effect on total dry weight, leaf chlorophyll index, the number of filled grains in panicle, panicle length, and paddy yield. In contrast to foliage application of nutrients in different stages of growth, there was no significant effect on the number of hollow grains in panicle, one-thousand seed weight and harvest index. Also, the highest mean was related to maximum tillering+ panicle initiation treatments and all stages and the least was related to the control treatment. The results showed that the application of macro and micronutrients especially in the late stages of vegetative growth and early reproductive growth in Sahel cultivar plays an important role in the improvement of photosynthesis and dry matter accumulation. Finally, the results of the present study showed that in Sahel cultivar, the foliage application of nutrients in the maximum tillering + panicle initiation, compared to the foliage application of nutrients in three stages, will be more economical and more effective.

The present experiment aimed to investigate the effect of humic acid application on physiological characteristics of rapeseed genotypes at different planting dates and selection of genotypes adapted to environmental conditions for development of rapeseed cultivation in cold and semi-arid temperate regions as a factorial randomized complete blocks design with three replications was conducted in Karaj during the cropping years 2014-2015 and 2015-2016. In the present experiment, planting date at three levels including 15 October, 25 October and the fifth of November, humic acid in two levels including spraying with pure water (no humic acid application) and humic acid application (foliar application of two per thousand) as a factorial in the main plots and canola genotypes (HW118, WPN6, HL3721, L14, Tassilo and Natali) were sub-plotted. Interaction of planting date, humic acid and genotype on grain yield, crown diameter, winter survival, proline and soluble carbohydrate content were significant at 1 percent level. Results showed that WPN6 produced the highest grain yield (5764 kilogram per hectare) and physiological traits at 15 October planting date and humic acid application. Also, in delayed sowing dates with humic acid application, HW118 with the highest studied traits is recommended.

The present research aimed to investigate the effect of different levels of phosphate soil with phosphorus-solubilizing microorganisms on yield and yield components of canola (Hyola 50 cultivar) carried out as factorial in a randomized complete blocks design with three replications in Golcheshme Azadehshahr Cultivation and Industry in cropping year 2017-2018. The first factor was the use of phosphate soil at four levels including 0, 50, 100 and 150 kilogram per hectare and the second is the use of phosphorus-solubilizing microorganisms at three levels including control (no use), phosphorussoluble bacteria (Pseudomonas fluorescensa) and phosphorus-solubilizing fungi (Mycorrhiza, Glomus mosseae). The results showed that the effect of soil phosphate on all investigated traits except harvest index was significant at 5 percent level. The effect of phosphorus solubilizing microorganisms on biological yield, grain yield, oil percentage, oil yield, seed phosphorus and leaf phosphorus was significant at 1 percent level. Interaction of soil phosphate and phosphorus solubilizing microorganisms on grain yield and oil yield was significant. Increasing phosphate soil up to 150 kilogram increased grain yield, so that grain yield was 2246 in the non-soil phosphate treatment (control) and 2431, 2510 and 2570 kilogram per hectare in 50, 100 and 150 kilogram phosphate soil treatments, respectively.

In order to determine the appropriate time of potassium and zinc spraying on yield and morphological characteristics of corn under low irrigation conditions, this research was carried out in summer of 2015 and 2016 in split split plots in a randomized complete blocks design and three replications in Ahvaz. The main factor included irrigation cut in three stages (12 leaf stage, emergence stage of thistle and control) and a sub plots including potassium spraying (8 leaf, 8+12 leaf and control) and sub-sub factor including zinc spraying (8 leaf, 8+12 leaf and control). The results showed the interaction of low irrigation tension, potassium foliar application and zinc were significant on the traits of grain yield, number of leaves, ear length, ear diameter, leaf nitrogen, leaf phosphorus, leaf potassium, and leaf zinc. The highest amounts of grain yield (1073. 8 gram per meter square), number of leaves per plant (14. 96), ear length (26. 6 cm), ear diameter (6. 8 cm) and leaf nitrogen (4. 3 percent) was obtained in complete irrigation with potassium and zinc spraying in two steps of 8 and 12 leaf stage. Improving all qualifications measured by two stages of potassium and zinc spraying under deficit irrigation conditions, could greatly compensate the damage caused by tension and increase the grain yield.

In order to expedite rapeseed maturity and reduce the overlap time of rice transplanting and rapeseed harvesting in paddy fields of Guilan province, the present experiment was conducted to investigate the effect of paraquat drying on a factorial randomized complete blocks design with three replications at research farm of Rice Research Institute of Iran-Rasht. Experimental factors considered paraquat consumption at three levels 0. 2, 0. 4 and 0. 6 liters per hectare and three applications time when grain moisture content in silique was 20, 40 and 60 percent. Also, a control treatment without paraquat consumption was considered. The results showed that drying treatment reduced significantly growth duration and accelerated 6 days in rapeseed harvest compared to control treatment and had no significant effect on grain yield (1965 kilogram per hectare), oil percent 43. 14 percent) and oil yield (848 kilogram per hectare). Among the investigated treatments, the consumption of 0. 2 liters per hectare of paraquat at 60 percent grain moisture level due to maximum germination percentage (95. 1 percent), grain yield (2254 kilogram per hectare), oil yield (984 kilogram per hectare) showed more significant difference than consumption treatments of 0. 4 and 0. 6 liters per hectare. According to the lack of negative effect drying treatments on grain yield and oil percent of rapeseed, it seems spraying of these compounds by reducing the overlap duration of rapeseed harvesting with rice transplanting in Guilan province, creating employment and preventing field useless in the second half of the year and increasing farmers' income is appropriated.

Ultraviolet is divided into three strips with UV-A (320-390nm), UV-B (280-320nm) and UV-C (254280nm) wavelengths and has adverse effects on the growth of a number of plants. Meanwhile, salicylic acids are a group of plant growth regulators that have unique biological effects on plants growth and development. Therefore, the aim of the present research was to investigate the application of salicylic acid to reduce the ultraviolet radiation tension of corn on germination, growth of shoot and root, fresh and dry weight, the amount of reducing sugars, malondialdehyde and other aldehydes. Maize plants treated with 1. 5 milli Molar salicylic acid were then treated for a period of one week with UV-A, UV-B, UV-C in a completely randomized design. This investigation showed that salicylic acid significantly increased germination of maize at 5 percent probability level. The results of these researches showed that UV-B and UV-C significantly reduced the growth of shoot, root, fresh and dry weight, whereas in the pre-treated plants with salicylic acid this decrease was significantly moderated to the five percent probability level. It was also observed that UV-A had no significant effect on growth of shoot, root, fresh and dry weight. The amount of malondialdehyde and other aldehydes in plants treated with UVB and UV-C significantly increased at a probability level of 1 percent, indicating the tension caused by UV-B and UV-C rays on the plant and the activation of defense mechanisms in these conditions. Significant decrease in the amount of leaf reductive sugars at 1 percent probability indicates radiation damage on photosynthetic apparatus. On the other hand, a significant increase in the amount of reducing sugars at the 1 percent probability level indicates the role of salicylic acid in increasing the resistance of this plant to UV-B and UV-C radiation. Considering the above, it can be concluded that the application of salicylic acid protects the plant against ultraviolet radiation.

In order to investigate the effect of mycorrhizal fungi and phosphate solubilizing bacteria on the quality traits and grain yield of Single Cross 704 maize under different irrigation intervals, the present experiment was conducted as split plots in a randomized complete blocks design with three replications in Hamidieh city in 2018 cropping year. Experimental treatments consisted of three levels of irrigation intervals (60 (control), 90 and 120 millimeter evaporation from Class A evaporation pan) in the main plots and the effect of combined application of mycorrhiza and fertilized phosphate 2 in four levels including (no use of mycorrhiza and fertilized phosphate 2 (control), mycorrhiza, fertile phosphate 2, Mycorrhiza + fertile phosphate 2) were in the sub-plots. The results showed that the effect of irrigation intervals and the combined effect of Mycorrhiza + fertile phosphate 2 on plant height, grain yield, biological yield, protein percentage were significant. The highest protein yield was obtained in 60 millimeter evaporation treatment from the pan and the lowest protein yield was allocated to 120 millimeter evaporation treatment from the pan. The results showed that combined application of mycorrhiza + fertilized phosphate 2 significantly increased grain yield and biological yield. The least of these traits were obtained from the absence of mycorrhiza + fertilized phosphate 2. The best grain yield (6000 kilogram per hectare) was obtained in irrigation treatment after 90 millimeter evaporation from the pan and combined application of mycorrhiza and fertilized phosphate 2, which increased 40 percent compared to 120 millimeter evaporation from the pan treatment and non-application of mycorrhiza + fertilized phosphate 2. In general, in order to achieve maximum quantitative and qualitative yield, the cultivation of maize plants using the combined effect of mycorrhiza and phosphate solubilizing bacteria in the conditions of 90 millimeter evaporation from the pan class A is recommended.