فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 63 (پاییز 1401)

The aim of this study was to investigate the effect of microbial inoculation on nutrient efficiency and quality of peppermint under drought stress in 2 crop years 2017-2018 and 2018-2019 in the Agricultural Research Center of Sarableh city located in Ilam province. This experiment was performed as a split plot in a randomized complete block design with 3 replications. Experiment with 2 factors, including drought stress in 3 levels of full irrigation (control), 70 and 50% of field capacity in main plots and growth-promoting bacteria and mycorrhiza in 6 levels including 1-control, 2-solute isolate Siderophore solvent + drought tolerant enhancer isolate, 3- mineral phosphate solvent isolate + drought tolerant enhancer isolate, 4- siderophore solvent isolate and drought tolerant enhancer isolate + dissolution isolate Mineral phosphate and isolates were increased by drought tolerance, 5-nitroxin commercial fertilizer and 6- mycorrhiza in subplots. The results of this study showed that most menthol essential oil in the combined treatment of siderophore soluble isolates and drought tolerant isolates + mineral phosphate soluble isolates and drought tolerant isolates and stress 50% of field capacity 24.2% was obtained compared to the lowest amount, ie control and full irrigation; Showed a 26% increase. At all levels of microbial inoculation except microbial fertilizer, the highest essential oil was always obtained at a stress of 50% of field capacity. The highest yield of peppermint essential oil was obtained in the treatment of commercial microbial fertilizer in the second year at the rate of 139.2 kg.ha-1. Microbial inoculation under stress at 50% of field capacity caused a 21% increase in dry shoot yield compared to the same level of stress in control. Growth-promoting bacteria and mycorrhizae increase quantitative and qualitative yield and increase the efficiency of nitrogen and phosphorus, which can have a significant effect on reducing costs and maintaining the ecosystem of agricultural systems.

Drought stress is one of the most important factors that limiting the growth and yield of plants. In recent years the use of various methods to reduce its negative effects has been considered by many researchers. This experiment was performed as a split plot in the form of randomized complete blocks with four replications in two years. The effect of foliar application of different ratios of magnesium and potassium on the morphological, biochemical and functional characteristics of maize (single cross cultivar 704) in different irrigation cycles (50, 75 and 100 mm evaporation from Class A evaporation pan) was evaluated. The results of analysis of variance showed that the interaction of irrigation and magnesium to potassium ratio on the characteristics of height, stem diameter, ear length, number of seeds per ear, potassium uptake, magnesium uptake, chlorophyll a, chlorophyll b, total chlorophyll, Carotenoids, proline, biological yield, grain yield and harvest index had a statistically significant effect. The results of the study of the effect of potassium and magnesium on morphological and biochemical changes in drought tolerance in maize (Single Cross 704 cultivar) showed that consumption of these elements significantly increased plant height, stem diameter, ear length, number of seeds per ear, uptake rate Potassium, magnesium uptake, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, proline, biological yield, grain yield and harvest index in water deficit conditions; So that the highest value of these traits in evapotranspiration conditions was 50 mm from the evapotranspiration pan and application of 200 kg of magnesium sulfate/ 300 kg of potassium sulfate. Also, foliar application of different concentrations of potassium sulfate and magnesium sulfate by increasing the uptake of potassium and magnesium, preserving leaf chlorophyll, resulting in more effective photosynthesis as well as increasing the concentration of proline in plant leaves, moderate the negative effects of water deficiency and corn tolerance to conditions. Improve water shortage.

Since the global approach to herbal medicine and chemical away from drugs, more attention to medicinal plants, is required. Fennel with variety of secondary metabolites in the treatment of flatulence, cough, digestive disorders and increases milk, used as one of the important medicinal plants. Drought stress is one of the most important non-polluting environmental stresses affecting crop production. To study the direct and indirect effects of evaluated traits on grain yield of fennel, an experiment was conducted in a randomized complete block design in two control and limited irrigation conditions separately with three replications on 19 fennel populations in the Agricultural Research Station, University of Tabriz. Combined analysis of variance revealed a significant differences between two irrigation conditions and evaluated populations at %1 probability level for some studied traits. As well as the population × conditions interaction effect was significant at 1% probability level for most traits. Correlations of grain yield with number of umbel in plant, plant height, internode number and biomass were significant positively in both irrigation conditions. Stepwise regression analysis showed that the number of grain per umbel and the number of umbel per plant, have the greatest impact on grain yield under optimum irrigation (R2=0.88). Also in the water deficit condition, number of umbels per plant and plant height had the greatest impact on grain yield (R2=0.60). Path analysis revealed that the number of umbel per plant had greatest direct effect on grain yield under control (0.90) and stress (0.53) condition respectively. Whereas the indirect effects were very inconsiderable in both conditions, therefore it is suggested that to selection of superlative populations for grain yield, the number of umbel per plant should be considered.

Temperature during flowering and seed filling is a very important indicator for estimating the yield potential of rapeseed. In order to evaluate the effect of heat stress due to delay in sowing date on agronomic characteristics of different rapeseed genotypes (including, Hyola420, Hyola50, Hyola60, SAN37, SAN34 and Dalgan) two separate experiments on two Conventional sowing date (11th Nov.) and late sowing date (16th Dec.) each in the form of a randomized complete block design with three replications was carried out in the research farm of Islamic Azad University, Ramhormoz Branch, during the growing season of 2016 and 2017. Each sowing date was considered as an environment and the data were finally analyzed by combined analysis. The results showed that with delay in sowing date and the occurrence of heat stress at flowering and seed filling stages, the number of flowers on the main raceme, ratio of siliques produced per flowers produced, number of siliques per plant, and branches per plant, number of seeds per silique, 1000-seed weight, silique length, plant height and reproductive period decreased and led to significant reduction in seed yield. Reducing silique numbers per plant had the highest contribution to reducing seed yield. In conventional sowing date, seed yield in Hyola 420 and SAN 34 was higher than other genotypes. Under heat stress conditions due to delay in sowing, seed yield in Hyola50 followed by SAN34 was higher than other genotypes and Dalgan had the lowest seed yield. The lowest percentage of reduction seed yield was belonged to Hyola50 (55%) and the amount of stress susceptibility index in this genotype indicated that it was semi-tolerant to late season heat stress. In conventional sowing date, genotypes that quickly reached to the flowering stage but had a longer flowering period, had higher yields. In late sowing date, significant negative correlation was observed between the duration of flowering with number of siliques per plant, number of seeds per silique and seed yield. SAN 34 had high yield in both conventional and late sowing dates and is suggested as a suitable genotype for achieving stable yield in Ramhormoz region.

Climate changs is one of the most important issues that has been observed in agriculture in recent decades and has limited production of crops. SSM-iLegum-Chickpea model was used to simulate the effect of climate change on evapotranspiration and leaf area index and growth indices of chickpea seed in Gonbad. First, meteorological data from the Dome Synoptic Meteorological Station from 1993 to 2017.The scenarios include increasing the temperature by two, four and six degrees, increasing the Co2 concentration by two times, and reducing rainfall by two percent, and a combination of the above scenarios, which total 9 scenarios. For the high temperature scenarios, the maximum and minimum daily temperature changes were added. Results of analysis of variance showed that in dry and irrigated conditions the effect of sowing date and climate change scenarios on all traits such as grain filling period, grain filling speed, evapotranspiration, leaf area index and total grain nitrogen except Harvest index nitrogen (NHI) was significant at 1% level in dryland conditions. But the interaction effect of planting date and climate change was only significant on evapotranspiration and leaf area index at 1% and NHI at 5% level. Duplication of concentrations of CO2 caused increasing about 6.2 in harvest index of nitrogen. Also, the best planting date for Gonbad city is the beginning of December in the simulation conducted for Gonbad.

Nitrogen fertilizer application and optimal density are important factors in increasing yield of canola. This study was carried out in order to investigate the effects of nitrogen fertilizers and plant density on some physiological characteristics, yield and yield components of Canola, as a factorial experiment in a randomized complete block design with three replications at Sheshdeh region of Fasa in 2018-2019. Nitrogen fertilizer factor in 12 levels including a1: urea (recommended) before planting and stem elongation, a2: urea (recommended) before planting, stem elongation and heading, a3: urea (recommended) in stem elongation and heading, a4: urea ( under recommended) before planting and stem elongation a5: urea (under recommended) before planting, stem elongation and heading, a6: urea (under recommended) in stem elongation and heading, a7: ammonium sulfate (recommended) before planting and stem elongation, a8: ammonium sulfate (recommended) before planting, stem elongation and heading, a9: ammonium sulfate (recommended) in stem elongation and heading, a10: ammonium sulfate ( under recommended) before planting and stem elongation a11: ammonium sulfate (under recommended) before planting, stem elongation and heading, a12: ammonium sulfate (under recommended) stemming and heading and density factor in three levels 50, 70 and 90 plants m-2.  Results showed that the effect of fertilizer on number of Raceme per subbranch and per plant was significant at 5% level and the effect of plant density on 1000 seed weight, total plant weight, seed yield and oil yield was significant. Ammonium sulfate (following fertilizer recommendation) had the highest number of Raceme per subbranch (48.6 per subbranch) and raceme per plant (73.5 per plant) in the shoot and bud stages. The highest biological and grain yield (12840 and 4258 kg.ha-1, respectively) were obtained at plant density of 50 plants.m-2. density 50 was significantly higher than 70 in terms of grain yield. Overally, the density of 50 plants.m-2 and the use of ammonium sulfate in the shoot and bud stages had the highest yield of Canola.

Azotobacter is an aerobic, gram negative and chemoorganotrophic bacterium, that is able to stabilize molecular nitrogen nonsymbiotically. The role of Azotobacter in plant growth is due to the production of growth-promoting hormones, the ability to dissolve insoluble phosphates, nitrogen fixation, increase stress resistance and biocontrol of plant pathogens. The aim of this study was to isolate and identify the indigenous Azotobacter from the soil of different areas of Tehran. The effect of tomato plant inoculation with isolates on growth promoting was also investigated. Finally, the growth conditions of the superior isolate were optimized.  Azotobacter isolates were obtained from soil samples using serial dilution method and identified by conventional biochemical tests. The nif H gene, encoding nitrogenase enzyme, was identified in isolates using real-time PCR technique. Then the tomato seeds were inoculated with isolates and seedling growth rate including stem and root length were measured during 34 days. The parameters of temperature, pH, aeration rate, and carbon and nitrogen sources were optimized for superior isolate. In this study, 27 isolates were identified as nitrogen fixing Azotobacter. Considering the results, all isolates showed a significant increase (p <0.05) in stem and root length of tomato plants compared to standard strain and negative control. Among them, isolate No. 21 had the greatest effect during 34 days of study and its best growth conditions in the presence of mannitol carbon source, peptone nitrogen source, 200 rpm rotation, 30°C and pH 7were acquired. According to the results of this study, the obtained indigenous isolates particularly isolate No.21 have the potential to be used as biological fertilizer after further investigations.

The most important component compatible with climatic diversity in agriculture is the planting date, which has the greatest impact on the phenological characteristics of the plant. Planting date is determined based on cultivar and climate of each region. In order this study was conducted to investigate the effect of seed and transplanting method on yield and yield components of quinoa cultivars in different planting dates in Ahvaz climatic conditions. The experiment as a split split plot in a randomized complete block design with four replications in crop years 2018-2019 and 2019-2020. Planting date was taken as the main factor in four levels (22 October, 1 November, 11 November and 21 November) and sub factor including planting method (transplanting and seed planting) and sub-sub factor also Quinoa cultivars (Giza1, Q26 and Titicaca). The results showed that delay in planting date reduced growth index (22, 39 and 26% LAI, DM and CGR recpectively), days to flowering (21%) and grain yield components (number of panicles per plant (42%), number grain per panicle (26%) and 1000-grain weight (21%)), grain yield (63%) and harvest index (54%) in quinoa. The highest value of these traits was related to the date of first sowing (October 22) and it was also found that transplanting in early sowing date is weaker than seed sowing but in late sowing date is better than seed sowing and reduces the negative effects of late sowing. Among the studied cultivars, Q26 cultivar was more acceptable in terms of growth rate (LAI (4.87), DMT (637.3 g. m-2), CGR (18.58 g. m-2.day) and yield components (number of panicles per plant (9.72) and 1000-grain weight (4.81 g)) and grain yield (1813 kg. h-1) than the other two cultivars. The highest grain yield (3058 kg.ha-1) belonged to Q26 cultivar on 30 October planting and 22 October planting and seed sowing (3148 kg.ha-1) and the lowest grain yield (769 kg.ha-1) belonged to Titicaca cultivar on 11 and 21 November planting. In general, it was observed that the sowing date in early autumn was suitable for planting different cultivars of quinoa in Khuzestan province due to the longer growing season and Transplantation at this date of sowing did not have much advantage in terms of yield compared to seed sowing, but in the date of delayed sowing reduces the negative effects.