musa Ebrahimpour; Pourang Kasraie; Hamidreza Larijani; Hamidreza Tohidi moghadam; Sahar Honarmand Jahromi
Abstract
Objective: The purpose of this experiment was to investigate the effect of foliar spraying of bacterial herbicides and aqueous extracts of plants on the morphological characteristics and starch of barnyard grass weed and rice.Methods: This experiment was conducted as split factorial based on a randomized ...
Read More
Objective: The purpose of this experiment was to investigate the effect of foliar spraying of bacterial herbicides and aqueous extracts of plants on the morphological characteristics and starch of barnyard grass weed and rice.Methods: This experiment was conducted as split factorial based on a randomized complete block design cityAmol with three replications in the two cropping years of 2018 and 2019. Factors included the foliar application of aqueous extracts plants and surfactant of sorghum, broccoli, nettle, eucalyptus, elder-berry, Streptomyces sp-albos containing thaxtomin, Xanthomonas campestris bacteria and control as the main factor, the concentration of the extract was zero, 5, 10 and 15 per thousand as a subfactor and the plant species of rice were Tarom cultivar and barnyard grass weed as a sub-sub factor.Results: By extracts foliar application, barnyard grass seed yield and biological yield decreased and the seed starch percent increased. Rice seed yield in the use of 5 per thousand broccoli extract and 5 per thousand Streptomyces sp-albos was not significantly different from the control. By increasing the concentration of the extract, seed yield and biological yield of rice and barnyard grass showed a further decrease. The lowest seed yield in rice at 3.16 tons/ha was related to elder-berry extract and in barnyard grass 0.68 and 0.61 tons/ha was related to nettle and elder-berry extract.Conclusion: According to the obtained results, Allelopathy and plant pathogens can be one of the basic ways to control weeds in a sustainable agricultural system.
Ashkan Jalilian; Ghorban Khodabin; MOJDEH SADAT Khayat Moghadam; Ehsan Zandi Esfahan; Fatemeh Amini; Nima Shahbazi; Mohammad Zargaran
Abstract
The use of nitrification inhibitor nitrapyrin is vital for the long-term maintenance of urea fertilizer in the soil and preventing its leaching. Therefore, this study was carried out to investigate the yield and physiological characteristics of different wheat cultivars under different levels of fertilization ...
Read More
The use of nitrification inhibitor nitrapyrin is vital for the long-term maintenance of urea fertilizer in the soil and preventing its leaching. Therefore, this study was carried out to investigate the yield and physiological characteristics of different wheat cultivars under different levels of fertilization and tillage systems. This study was performed as a split-split plot based on a randomized complete block design with three replicates in Karaj during two cropping seasons (2019-21). The experimental treatments included two tillage levels (no-tillage and conventional tillage) in the main plot and three fertilizer levels (urea, nitrapyrin + urea combination and control (main plot), and two cultivars (Rokshan and Pishgam) in the secondary plot. The results of the composite analysis showed that the highest yield of wheat grain was obtained in Rakhshan cultivar with 8331 kg/ha and the level of urea + nitrapyrin fertilizer was obtained in no-tillage, which was 6.15% superior to the level of urea. Also, in both tillage systems, the highest amount of leaf area index and nitrogen productivity index was obtained in the same treatment, so compared to the treatment of urea application, 6.1%, 2.7% in no-tillage and 0.8% and 1.3% in Cultivation was more common. In general, nitrapyrin improved wheat yield in both tillage levels. In addition to improving plant performance, the use of nitrapyrin can also be effective in reducing environmental hazards caused by the use of chemical fertilizers such as urea.
farzaneh Pimard; Abdolrahman Mohammadkhani; Ali Niazi; Alireza Shahsavar; Mohammad-Reza Nouri-Emamzadei
Abstract
Drought stress is one of the limiting factors of agriculture in many parts of the world, especially Iran. Understanding the mechanism behind drought stress’ effect on physiological and biochemical processes of genotypes is very useful for selecting and breeding genotypes compatible with Iranian ...
Read More
Drought stress is one of the limiting factors of agriculture in many parts of the world, especially Iran. Understanding the mechanism behind drought stress’ effect on physiological and biochemical processes of genotypes is very useful for selecting and breeding genotypes compatible with Iranian conditions. For this purpose, the present study has been conducted in 2018-2019 in the Biotechnology Research Institute of Shiraz University to investigate the effect of drought stress on physiological and biochemical characteristics of both years’ old pomegranate seedlings of Wonderful cultivar in greenhouse conditions. Irrigation has been carried out at four levels of 100% (control), 75%, 55%, and 35% of field capacity for 50 days. The experiment is based on a completely randomized design with three replications. The results show that drought stress has significantly increased carotenoids, flavonoids, malondialdehyde, and proline. The relative leaf water content, cell membrane stability and anthocyanins has decreased, though there has been no significant difference in chlorophyll and glycine betaine levels between drought treatments. Also, the hydrogen peroxide (81%) and activity of superoxide dismutase (480%), catalase (96%), and ascorbate peroxidase (96%) in 35% of field capacity significantly has increased. According to the results of this study, especially the increase in proline and antioxidant enzymes under drought stress, tolerance mechanisms in pomegranate cultivar Wonderful can be associated with active osmotic regulation and active enzymatic antioxidant system.
Somaye Amraee Tabar; Ahmad Ershadi
Abstract
In this study, the drought tolerance threshold and relationships between some biochemical and physiological responses of two stone fruit rootstocks, Cadaman and GF677, have been investigated. For this purpose, a pot experiment has been carried out in a greenhouse using factorial trial based on a completely ...
Read More
In this study, the drought tolerance threshold and relationships between some biochemical and physiological responses of two stone fruit rootstocks, Cadaman and GF677, have been investigated. For this purpose, a pot experiment has been carried out in a greenhouse using factorial trial based on a completely randomized design with three replications. One-year-old rooted cuttings of two rootstocks are exposed to drought stress (-0.1 (control), -0.6, -1.1, -1.6 MPa) by adding different amounts of polyethylene glycol-6000 to Hoagland nutrient solution. Significant increase in electrolyte leakage and decrease in leaf relative water content of Cadaman and GF677 rootstocks has occurred at -0.6 and -1.1 MPa, respectively. Concentration of photosynthetic pigments and quantum yield of photosystem II (FV/FM) are less affected by drought stress, decreasing significantly in Cadaman and GF677 rootstocks at -1.1 and -1.6 MPa, respectively. Under severe drought stress, photosynthesis, transpiration, intercellular CO2 concentration, and stomatal conductance in Cadaman rootstock decline more considerably, compared to GF677. Moreover, at drought stress of -1.6 MPa, GF677 does not significantly reduce its photosynthesis, despite a substantial decrease in transpiration; however, the relative decrease in photosynthesis of Cadaman at -1.6 MPa has been much greater than the relative decrease in its transpiration and intercellular CO2 concentration, which, in turn, results in a drop in water use efficiency and mesophilic conductance of Cadaman leaves, compared to GF677. It seems that considerable reduction in photosynthesis in Cadaman rootstock, along with stomatal limitations, is largely due to non-stomatal constraints such as loss of cell membrane intact and reduction of chlorophyll, carotenoids and chlorophyll fluorescence. Results show that GF677 rootstock has higher tolerance to severe drought stress, compared to cadaman.
mohammad reza malekzadeh shamsabad; Majid Esmaeilizadeh; Hamidreza roosta; fatemeh nazoori
Abstract
In soilless culture, lack of correct management in fertigation causes stress in plants due to restricted root volume and low water holding capacity of substrate. The present study aimed to assess managing the fertigation practice and foliar application of potassium sulfate in soilless culture of strawberry ...
Read More
In soilless culture, lack of correct management in fertigation causes stress in plants due to restricted root volume and low water holding capacity of substrate. The present study aimed to assess managing the fertigation practice and foliar application of potassium sulfate in soilless culture of strawberry cv. paros. A factorial experiment was conducted with two factors including fertigation frequency at three levels (1, 4 and 10 times per day) and foliar application with potassium sulfate at three levels of concentration (0 as control, 1 and 2 g/L). The experiment was carried out based on a complete randomized design with three replications in Vali-e-Asr University of Rafsanjan. Results indicated that increasing the fertigation frequency up to four times a day led to a significant increase in dry weight of shoot and root, number of fruits, concentration of chlorophyll a and b, leaf relative water content and leaf Ca and Mg content. The highest values of leaf area, fruit weight, number of inflorescence as well as potassium and iron content of leaf and root were obtained by 10 times of fertigation per day. Potassium sulfate foliar application with concentration of 1 g/L had the most effect on leaf area as well as shoot, root and fruit dry weight, vegetation index increased in plants treated with 2 g/L potassium sulfate compared with those without any foliar application treatment. The highest content of leaf soluble carbohydrates belonged to the plants treated with once-a-day fertigation and foliar application of 2 g/L potassium sulfate.
Somayeh Karami; Hashem Hadi; Mehdi Tajbaksh; Seyed Ali Mohammad Modarres-Sanavy
Abstract
In order to study the effect of different levels of irrigation, nitrogen and zeolite onchlorophyll content, forage yield and quality of amaranth, a split plot factorial experiment was conducted as randomized complete block design with three replications at the Research Farm of Tarbiat Modarres University ...
Read More
In order to study the effect of different levels of irrigation, nitrogen and zeolite onchlorophyll content, forage yield and quality of amaranth, a split plot factorial experiment was conducted as randomized complete block design with three replications at the Research Farm of Tarbiat Modarres University during 2013 and 2014 growing seasons. Main factor was three irrigation regimes, irrigation after depleting 40, 60 and 75 percent of soil available waterand sub factor was the combination of the two factors: nitrogen levels 0, 80, 160 and 240 kg.h-1 and zeolite levels 0 and 10 ton.h-1. Results showed that increasing irrigation intervals, especially irrigation after depleting 75% of available water, decreased chlorophyll (37%), forage yield (40%), digestible dry matter (18%), crude protein (17%) and ash (16%) but increased neutral detergent fiber (16%) and acid detergent fiber (7%) compared to control irrigation treatments. Zeolite application under water deficit stress conditions increased chlorophyll, forage yield, digestible dry matter, crude protein and ash, and reduced NDF and ADF. Nitrogen consumption more than 80 kg.h-1 had no significant effect on forage dry yield and quality under soil water deficit conditions and application of zeolite; Therefore, Nitrogen application (80 kg.h-1) was sufficient to obtain suitable forage yield and quality of the amaranth with zeolite application.
Abstract
In order to evaluate the effect of irrigation withholding and foliar potassium application on some physiological traits (photosynthesis, cell membrane stability and chlorophyll) and harvest index of wheat (Triticum aestivum L.), an experiment was carried out using a split plot factorial based on a randomized ...
Read More
In order to evaluate the effect of irrigation withholding and foliar potassium application on some physiological traits (photosynthesis, cell membrane stability and chlorophyll) and harvest index of wheat (Triticum aestivum L.), an experiment was carried out using a split plot factorial based on a randomized complete blocks design with three replications in 2011-2012 in two locations: Seed and Plant Certification and Registration Research Institute, Karaj and Agricultural and Natural Resources Research Center, Yazd. The experimental factors were included drought stress (three levels of irrigation withholdings were irrigation withheld from ear emergence to physiological maturity, irrigation withheld from grain filling to physiological maturity, and normal irrigation) foliar potassium application (without potassium application, 1.5 and 3.0% K2SO4) and genotype (two wheat cultivars of ‘Marvdasht’, ‘Pishtaz’and aline‘WS-82-9’). Results showed that the studied characteristics were significantly reduced by increasing drought stress level. The highest harvest index was observed in ‘WS-82-9’ in Karaj under normal irrigation (32.69%) and the lowest harvest index was obtained from ‘Marvdasht’cultivarin Yazd, under severe stress (11.50%). Genotypes were different for cell membrane stability and the lowest rate was belonged to ‘Marvdasht’ (35.5%). Foliar application of 3.0% K2SO4 caused to significant differences in physiological characteristics, especially for leaf photosynthesis under severe drought stress condition: photosynthesis increased 99.1 and 69.7% in Yazd and Karaj, respectively. It can be concluded that cultivating of ‘WS-82-9’ and spraying of 3.0% K2SO4 were effective to moderate drought stress, especially when fields have limitations for irrigation water at the end of crop life cycle.
Asghar Rahimi; Mohammad Reza Jahansooz; Hamid Rahimian mashhadi; Majid Pouryousef; Shahab Maddah Hosseini
Volume 11, Issue 2 , November 2009, , Pages 49-63
Abstract
Photosynthesis, stomatal conductance and leaf water potential characteristics were examined in two plantago species (Plantago ovata Forssk and P. psyllium L.), with gradually improving water stress for several days and permitting to recover by re-watering (withholding for 2, 4, 6, 8 and 10 days) in Melbourne ...
Read More
Photosynthesis, stomatal conductance and leaf water potential characteristics were examined in two plantago species (Plantago ovata Forssk and P. psyllium L.), with gradually improving water stress for several days and permitting to recover by re-watering (withholding for 2, 4, 6, 8 and 10 days) in Melbourne University in 2006. Factorial experiments based on completely randomized design with four replications were used. The photosynthetic rate and stomatal conductance decreased rapidly by withholding water. After re-watering the recovery rate of photosynthesis and stomatal conductance decreased gradually, as the days became longer. The different rates of recovery of photosynthesis and stomatal conductance followed by drought stress. However, the potentional of photosynthesis recovery was more than stomatal conductance. It is also concluded that French psyllium had higher mesophyl and stomatal conductance recovery when compared to Isabgul, although recovery of photosynthesis in Isabgul was higher than French psyllium. The results showed a clear and close correlation between leaf water potential and recovery level of photosynthesis rate and stomatal conductance. A close correlation was also observed between photosynthesis and leaf water potential, stomatal conductance and relative water content.