فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 44 (زمستان 1396)

This study was conducted to investigate the effects of water deficit stress, nitrogen fertilizer and zeolite on growth parameters, biomass and seed yield of fenugreek. A split factorial experiment based on a randomized complete block design with three replications was conducted at the Research Field of Tarbiat Modares University in 2014 and 2015. Five irrigation regimes (unstressed, mild stresses during the vegetative and reproductive stages, respectively; severe stresses during the vegetative and reproductive stages, respectively) were randomized to the main plots. Subplots consisted of six treatments of a factorial combination of three levels of nitrogen fertilizations (untreated plots, vermicompost fertilizer at a rate of 2.7 t.ha-1 and nitrogen chemical fertilizer at a rate of 11 kg.ha-1) and two rates of zeolite (0 and 9 t.ha-1). In both years, increasing severity of water deficiet stresses reduced leaf area index, crop growth rate, plant height, biological and seed yield of fenugreek; Thus, severe water deficit stress at the reproductive stage without fertilizer and zeolite (with the least amount of biological and grain yield) compared with that of control, caused 60.96 and 48.09 percent reduction in biological yield and 80.18 and 75.62 percent reduction in grain yield, in both years, respectively. Application of nitrogen fertilizer, especially vermicompost, resulted in a significant increase in the leaf area index, crop growth rate of fenugreek in various stages of development, thereby increased biological and grain yield in different irrigation regimes. In various irrigation regimes, higher leaf area index, crop growth rate and finally more yield produced with application of vermicompost or zeolite.

To study the effect of water deficit stress on leaf area, radiation use efficiency and dry matter production of soybean and millet in intercropping, a split plot experiment based on randomized complete block design with three replications was carried out, in 2015 at the Research Station of Agricultural Faculty of Bu-Ali Sina University. The main factor consisted of three levels of water deficit stresses (irrigation after 60, 90 and 120 mm evaporation from pan) and sub factor of five replacement intercropping treatments sol cropping of soybean (100S), sol cropping of millet (100M), 67 % S 33 % M (67S:33M), 50 % S 50 % M (50S:50M) and 33 % S 67 % M (33S:67M). The results showed that the highest leaf area index of soybean and millet in sol cropping were 5.68 and 3.23 respectively. Severe water deficit stress significantly decreased leaf area index of soybean and millet by about 30.03 and 30.33 percent, respectively, as compared to well-watered condition. The highest dry matter (613 and 540 g.m-2) belonged to sol cropping of soybean and millet, respectively. Severe water deficit stress reduced dry matter of soybean and millet by 39.87 and 31.556 percent respectively as compared to the control. Radiation use efficiency of millet in (33S:67M), (50S:50M) and (67S:33M) intercropping ratios were 24.85, 29.86 and 26.76 percent more than sol cropping of millet, respectively. Radiation use efficiency of soybean reduced in the intercropping. Mean radiation use efficiency of soybean in growing season ranged from 0.97 g.mj-1 in the (33S:67M) ratio to 1.77 g.mj-1 in the sol cropping of soybean. The results showed a negative effect of water deficit stress on radiation use efficiency of both millet and soybean.

To evaluate the effects of water deficit stress and growth regulator (Brassinosteroid) on some physiological characteristics cultivars of safflower, an split plot factorial experiment based on randomize complete block design with 3 replications was conducted at the Research Farm of Faculty of Agriculture, Mohaghegh Ardabili University in 2014. Water stress was in three levels: 80 mm evaporation (normal irrigation); 120 mm evaporation (low water stress); 160 mm evaporation (high water stress) from evaporation pan of class A which were assigned to main plots and three cultivars of safflower (Goldasht, Spiny Sina and Faraman) and two levels of Brassinosteroid, control and 10 -7 mol. in sub plots. The reasults showed that water stress decreased stomatal conductance, photosynthetic rate, sub-stomatal CO2, water-use efficiency, chlorophyll content index (SPAD), seed yield, leaf soluble protein and transpiration rate. The results also showed that use of brassinosteriod, increased photosynthetic parameters and reduced transpiration. Irrigation at evaporation of 80 mm from pan, resulted in the maximom amount of transpiration and stomatal conductance to the Faraman cultivar, sub-stomatal CO2 to Sina spiny cultivar and chlorophyll content index (SPAD) to Goldasht cultivar. Irrigation at 120 mm evaporation from class A pan resulted in the maximum amount of transpiration and stomatal conductance to Goldasht cultivar, while the highest sub-stomatal CO2, belonged to Sina spiny. Irrigation at 160 mm evaporation from class A pan resulted in the maximum amount of transpiration, stomatal conductance, chlorophyll content index (SPAD) and the sub-stomatal CO2 to Goldasht cultivar. It seems that Goldasht cultivar under both mild and severe drought stresses tolerates drought better than the other two cultivars in Ardabil rigion.

This study was conducted to evaluate the response of hybrid varieties of maize (single cross 260) under drip irrigation treatments in the Fars province in 2012 and 2013 at the Experimental Field of Islamic Azad University of Shiraz. Irrigation levels were 20, 40, 60 and 80% deplection of moisture contents and experiment was conducted in a randomized complete block design. The triats measured were leaf area index, dry matter yield and total biomass in 2012 and the measurements were repeated in 2013 to validate the use of SWAP model. The results showed that simulated yield changes by the use of model, at different levels of irrigation levels in the farm, corresponded with the yield changes in the field. Statistical indices including correlation coefficient (greater than 0.9), t-test (greater than 0.05), the root mean square error and normalized root mean square error (RMSEn) equal to 1.9-6.9, indicate good performance for grain yield and total biomass by using the SWAP model.

To study the effects of plant growth promoting rhizohacteria on yield and yield components of four chickpea (Cicer arietinum L.) cultivars in Ilam region under rainfed conditions, a field experiment was conducted using factorial arrangement based on randomized complete block design with three replications at the Agricultural Research Center of Ilam during 2014-2015 cropping seasons. Cultivars under study were Azad, Hashem, Arman and an ecotype. Treatments were plant growth promoting rhizohacteria (without inoculation, 10 kg nitrogen fertilizer, 20 kg nitrogen fertilizer, Azospirillum brasilense숫憢 nitrogen fertilizer, Azospirillum brasilense kg nitrogen fertilizer, Azospirillum brasilense kg nitrogen fertilizer, Azotobacter chrococcum, without nitrogen fertilizer, Azotobacter chrococcum kg nitrogen fertilizer, Azotobacter chrococcum kg nitrogen fertilizer. The interaction effect of cultivar×plant growth promoting rhizohacteria (PGPR) were significant on pods per plant, seed per pod, 100-seed weight, seed yield, biological yield, plant height and protein content; Thus, application of chemical fertilizer and PGPR in these cultivars increased all traits under study. The highest mean seed yield of 1533 kg.ha-1 was obtained from interaction effect of Azad cultivars×Azospirillum kg nitrogen fertilizer and lowest grain yield with mean yield of 529 kg.ha-1 observed from interaction effect of ecotype×without inoculation that increased 65.5% to check treatment. Inoculation with Azesperilluim was found to be more effective in Azad and Hashem cultivars and inoculation with Azotobacter was found to be more effective in Arman cultivar and ecotype. According to the results obtained from this study, Azad cultivar and inoculation with Azospirillum kg nitrogen fertilizer produced highest sedd yield under rainfed condition of Ilam Agricultural Research Center.

This experiment carried out during 2010-11 and 2011-12 cropping years to study the effect of variant levels of fertilizers containing nitrogen, normal irrigation and irrigation hindering on some agronomical characteristics of isabgol, in Smaeel-Abad Agriculture Research Center of Qazvin. The research was carried out by using two split plot experiments based on randomized complete block designs with three replications. The experiments were repeated for two consecutive years and finally the research results were performed by combined analysis. Main plots were normal irrigation (I1) and cutting off irrigation during seed filling stage (I2), sub plots were nitrogen containing fertilizers: vermicompost, cattle manure and chemical nitrogen fertilizer (urea 46%) with three levels, containing 30, 60 and 90 kg.ha-1 of pure nitrogen. Effects of irrigation and nitrogen containing fertilizers on mucilage yield (P≤0.01) and mucilage percentage (P≤0.05) were significant. Interactions of irrigation × nitrogen containing fertilizers on biological yield and relative water content (P≤0.05), seed yield and 1000 seed weight (P≤0.01) were also significant. According to results of this research; the highest application level of vermicompost in normal irrigation condition, showed better results for production of isabgol plant in the research area.

To effects of seed priming with ethanol, methanol, boron and manganese on some morphophysiological characteristics of rapeseed under water deficit stress was investigated in greenhouse using a factorial experiment based on completely randomized block design with three replications at the Research Station of the Islamic Azad University, Tabriz Branch, Tabriz, Iran, during growing seasons of 2012-2013. Treatments were 5 priming treatments: without seed priming, control, seeds priming with 2% ethanol, 2% methanol and with 0.5% of H3BO3 and of MnSO4.H2O solutions) and 4 levels of different regimes of irrigation: (irrigation at 100%, 75%, 50%, and 25% of field capacity. The analysis of variance showed significant effects of seed priming on mean germination time (MGT) and germination speed (GS). The analysis of variance also indicated significant effect of seed priming and water deficit stress on relative water content (RWC) and number of pod per plant. Furthermore, the results showed a significant difference of interaction between seed priming and water deficit stress for seed yield per plant, stomata resistance and dry biomass weight per plant. The detailed results of this study showed that ethanol seed priming increased mean germination time (MGT) and germination speed (GS) by 65% and 72% respectively. Seed priming by ethanol increased relative water content (RWC) by 8% and number of pod per plant by 9% as compared with those of untreated seeds. Furthermore, seed priming by ethanol at 100% FC increased seed yield by 85% as compared with seed treatment by MnSO4.H2O at 25% FC.

Determination of crop NPK requirements is important for proper crop growth. To determine the NPK nutrition of henna (Lowsonia inermis L.), a factorial experiment based on randomized complete block design was carried out in the Shahdad, Kerman province, in 2015-2016. In this study, response of three henna ecotypes (Bam, Shahdad and Roodbar) with four fertilizer combinations consisting of nitrogen, phosphorus and potassium (N: K: P, 0: 0: 0, 100: 50: 50, 200: 100: 100, 300: 200: 150 kg/ha) were investigated for some growth indices like CGR, RGR, net photosynthesis, transpiration rate and stomatal conductance. The results indicated that the highest mean of CGR, RGR, net photosynthesis, transpiration rate, stomatal conductance and total dry yield belonged to Shahdad ecotype. While, there was no statistically significant difference between the Shahdad and Roodbar ecotypes for leaf dry yield. The effect of NPK nutrition treatment on the most of traits measured was significant at 1% probability level. The highest mean of traits measured belonged to NPK combination of 300: 200: 150, while the difference was not significant from 200: 100: 100 for leaf dry yield and RGR. In this study, the interaction of ecotype and nutrition was not significant for the traits under study. Therefore, according to the results, it can be concluded that Shahdad and Roodbar ecotypes and combinations of nitrogen, phosphorus and potassium fertilizers with a ratio of 200: 100: 100 are appropriate for henna in Shahdad climatic conditions.

To compare the yield and physiological growth indices of three Iranian sesame cultivars under the application of chemical and biological potassium fertilizers a pot experiment was conducted in the summer of 2015 in greenhouse. This study was performed as factorial arrangement based on a randomized complete block design with three replications. The potassium fertilizer application, based on soil test, was in four levels (K1:K2SO4 50%, K2: Bacillus circulans L., K3: Bacillus megatherium L. and K4: KSB1⤠ and three sesame cultivars used were Ultan, Yekta and Dashtestan 2. The plant samples were taken from 30 to 105 days after sowing with 15 days intervals. LAI, TDM, CGR, NAR and RGR were measured during the different growth stages. The results showed that the Yekta cultivar produced the highest seed yield (18.62 g.plant-1). Ultan produced highest growth rate as compared to the other cultivars. Furthermore, it responded differently to the application of biologic KSB1 fertilizer as compared to the other treatments and cultivars. KSB1 improved and accelerated plant growth rate at 90 days after sowing. While, the use of chemical potassium sulfate, KSB2 and combined application of Bacillus circulans L. with KSB1 and 2 improved growth 105 days after sowing.

Environmental protection and safity of agricultural products are two major goals in sustainable agriculture. Hence, using plant growth promoting rhizobacteria may be effective to reduce chemical inputs. Therefore, a field split plot experiment based on a randomized complete block design (RCBD) was conducted at Ghaemshahr, Mazandaran Province in 2015. Treatments were consisted of three levels of phosphorus (P) fertilizer (0 or control, 50 and 100 kg.ha-1 as triple super phosphate) and coinoculation of rice seed and seedling with Trichoderma virens and Piriformospora indica fungi with four levels (uninoculated control, inoculation of seed or seedlings and seed seedlings inoculation). Results indicated that inoculation with these fungi significantly and positively affected the morpho-physiological traits and paddy yield of rice plant in all P levels. When, 0, 50 and 100 kg.ha-1 was applied, seed inoculation resulted in significant increase of panicle number per plant (33, 19 and 40 percent, respectively), filled seeds per plant (21, 45 and 58 percent, respectively), biological yield (31, 6 and 18 percent, respectively) and paddy yield (37, 48 and 43 percent, respectively). Also, fungi inoculation of rice seeds, seedlings and seeds seedlings improved paddy yield up to 48, 53 and 53 percent and 43, 44 and 15 percent when 50 and 100 kg.ha-1 of P was applied, respectively. In general, results indicated that all three methods of fungi inoculation had positive effect on rice plants under all P levels, which could be related to those fungi ability to improving the parameters under study such as panicle number per plant and biological yield. In conclusion, the positive effects of using both microorganisms and P were more pronounced than using P alone.

To investigate the response of safflower agronomic characteristics to time, rate and method of nitrogen applications, an experiment was carried out at the research Field of Payaam Nour Arak University in Markazi province during 2011. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Time of nitrogen treatment was with three levels (half in planting date half in rosette stage), (half in rosette stage half in stem elongation) and (half in stem elongation half in boll forming stage), urea application was two levels (150 and 300 kg.ha-1) and method of application was with three levels (mixed with soil, used in irrigation water and foliar application). Each plot consisted of 4 rows, 5 m long with 50 cm between rows and 5 cm between plants on the rows. Results indicated that the effect of application time on the characteristics like: height of branch, number of sub-branches, number of seeds per m-2, number of seeds per plant, biological yield of bolls, seed yield of bolls, harvest index of bolls were significant. The effect of nitrogen treatment rates on branch height, number of sub-branches, number of seeds per m-2, number of seeds per plant, biological yield of boll, harvest index of boll, and nitrogen use efficiency were also significant. Mean nitrogen use efficiencies for foliar application was 63.27% and for soil mixed application was 6.86%. Thus, it seems that foliar application of urea not only decreases environmental but also increases nitrogen use efficiency.

Growing berseem clover (Trifolium alexandrinum) prior to rice can be a good strategy for reduction of chemical fertilizer consumption and increasing the sustainability of the rice cropping systems. For this purpose, a field experiment was conducted by using a split-plot based on randomized complete block design (RCBD) with three replications, at the Rice Research Station of Tonekabon, Iran in 2014-2015. Growing berseem clover and use of fallow (control), were assigned to main plots, and amount of phosphorus fertilizer (without P and 25, 50, 75 and 100 kg.ha-1 P) to the sub-plots. At crop maturity, seed yield, yield components and phosphorus content of seeds were evaluated. The results showed that seed yield of rice (7566.3 kg.ha-1) after clover was significantly higher than after fallow (6465.1 kg.ha-1) (p

Highest seed yield of wheat can be produced when planting date coincides with suitable environmental condition for its growth and development. To study the yieldand yield components of some spring wheat varieties in different sowing dates, a field experiment was conducted in Neishabour during 2013-2015 cropping seasons, using a split plot experiment based on a randomized complete block design with three replications. Three sowing dates were October 11, November 10 and December 10 which were assigned to main plots and six sping wheat cultivars Chamran, Pishtaz, Bahar, Sirvan, Sivand and Parsi to the sub –plots. Results of combined analysis showed that sowing date had significant effect on the number of spikes per square meter, the number of seed per spike, number of days to heading, number of days to maturity, grain filling period, seed yield and harvest index. The highest and lowest seed yields were obtained from sowing date of the October 11 and December 10 respectively. Interaction between year and sowing date was significant for seed yield. Delaying the sowing date decreased seed yield for first and second year by 46% and 48% respectively. Mean seed yield of varieties for two years was 5649 kg.ha-1. The mean grain yield for first and second year were 6235 and 5064 kg.ha-1 respectively. The results of correlation analysis showed that the number of spike per square metter had the most effect on seed yield and yield components. In general, results revealed that highest yield for the varieties under study are sowing date of October 11. Parsi is the best one for this region, because is produced highest seed yield, number of spikes per meter squared LAI at anthesis.

Planting of narrow leaf cover crops may have an important effect in reducing the use of herbicide. Cover crops, therefore, are an effective tools in the non-chemical weed management in sustainable agriculture. To evaluate the effect of cover crops on weeds control and essential oil yield of mint, a factorial experiment based on randomized complete blok design with three replications was conducted at the Research Field Mohagheghe Ardabili University, Iran, in 2015. First factor consisted of: spring wheat, spring barley, winter rye, winter wheat, winter barley, mixed winter rye winter barley and second factor consisted of: cutting mulch near ground, heading living mulch 20-30 cm. from ground and killing ground cover by herbicide. Also, two controls were: without cover crop and weeding without cover crop and without weeding, inside conducted experiments. The results showed that the main effect of cover crops management had significant effect on peppermint content and dry weight and density of weeds. Comparison of interaction effects showed that highest leaf oil yield in heading living mulch of winter wheat, undercutting spring barley and winter rye was (52g/h). On the average in three stages of sampling the percent biomass control of redroot pigweed andfield bindweed in undercutting mulch, heading living mulch, killing cover crops with herbicide were 38% and 66% and their density control were 44% and 70%, respectively.