Morteza Pouzesh Shirazi; Hassan Haghightnia; Rahim Khademi
Abstract
Introduction: Tomato is one of the most important vegetables that are used by human. High price of tomato due to its out of season production in Bushehr province has made a great tendency for farmers of this area to cultivate it in fall and winter in nearly 12000 hectares in the province. Mean annual ...
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Introduction: Tomato is one of the most important vegetables that are used by human. High price of tomato due to its out of season production in Bushehr province has made a great tendency for farmers of this area to cultivate it in fall and winter in nearly 12000 hectares in the province. Mean annual precipitation is about 250 mm per year. Maximum and minimum annual temperatures are 51 and -1 Celsius degrees. Mean annual evaporation is 3000 mm. Recent droughts and going down of water table because of over usage of underground water are main problems of this region that have enforced farmers to decrease irrigation water utilization and try to increase water use efficiency by using new technologies. Therefore, any new technical methods which can increase water use efficiency will help crop production quality and quantity and result in yield stability in the region. Many researchers have proved that mycorrhizal fungi can improve agricultural systems sustainability because of their ability to increase water absorption due to their long and expanded hyphae. Also they are known to increase nutrient uptake from soils even poor in minerals. Therefore, a greenhouse project was designed to determine the effect of Arbuscular mycorrhizal fungi on nutrients uptake and water use efficiency of tomato under drought stress in Bushehr province in southern Iran.
Materials and Methods: The experiment was carried out on completely randomized block design in factorial with three replications during 2016-2017 in the greenhouse of Bushehr agricultural and natural resources research organization located in Southern Iran. Factors were as follows: 1) four Arbuscularmycorrhizal fungi (Glomus mosseae ،Glomus intraradices، Glomus vsersiform and Glomus caledonium) and a control (without inoculation), 2) irrigation at three levels based on soil moisture depletion at I1=25, I2=50 and I3=70 percent of available water to show stress (from non-stress to low and high stress levels). Soil used for this experiment was dried in sunshine for one month to be evacuated from any native fungi. Soils of the region are calcareous ones with low salinity limitation (EC= 3.70 dS/m) and poor nutrition elements and slightly alkali (pH=7.9). Inoculation of roots by fungi was done by pouring one spoon of fungi near tomato roots while cultivating the transported seedlings in the pot. This would help the roots to be exposed to fungi directly while spreading through growing. Irrigation water used were 22.3, 20.1 and 17.7 liter for each pot filled with 10 kg soil during the season. The experiment lasted 100 days and tomato properties were measured such as yield, colonization percent, nutrition elements concentration and also, water use efficiency. Dried leaves were milled and put in furnace at 550 Celsius degrees. Roots were soaked in water for five minutes to be detached from soil and cleaned toughly. Detached roots were maintained in small glass jars filled with alcohol and were kept in refrigerator at 5 Celsius degrees. Roots were then colored by Try pan blue method and root colonization percent was measured by Grid line intersect method.
Results and Discussion: Results showed that interaction effect of mycorrhizal fungi and irrigation levels was significant at 1% level on tomato properties (except for N concentration in leaves). Mean comparison with Duncan`s test proved that increase in drought stress caused decrease in all tomato properties but fungi inoculation could mitigate water shortage in comparison to non-inoculated tomatoes Higher drought stress decreased colonization significantly. Drought stress caused significant deficiency in nutrition elements such as N, P and Fe, however some elements such as K, Zn and Mn were increased in medium drought stress. Inoculation with all mycorrhizal fungi improved nutrition elements concentration in tomato leaves. Water use efficiency was increased 67.9, 49.6 and 52.1 percent from non to medium and high stress respectively in tomatoes treated with Glomus intraradices.
Conclusion: Using of mycorrhizal fungi specially Glomus intraradices and Glomus caledonium increased tomato water use efficiency and improved growth properties due to the increment of water resistance ability in plant. This phenomenon is caused by higher nutrition elements uptake by roots and optimization of water relationship in tomato in the presence of mycorrhizal fungi. According to results, it is suggested tomato roots inoculation with mycorrhizal fungi especially in regions with high water stress potential.
Majid Basirat; Hassan Haghighatnia; Seyed Majid Mousavi
Abstract
Introduction: Fertilizer recommendation in orchards based on soil testing is not accurate because findings showed that there is not significant correlation between nutrients concentration in the soil and plant. Therefore, studying the nutritional status in orchards is usually based on the plant testing. ...
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Introduction: Fertilizer recommendation in orchards based on soil testing is not accurate because findings showed that there is not significant correlation between nutrients concentration in the soil and plant. Therefore, studying the nutritional status in orchards is usually based on the plant testing. In order to evaluate the nutritional status ofplants, different methods, such as Compositional Nutrients Diagnosis (CND), Diagnosis and Recommendation Integrated System (DRIS), Deviation from Optimum Percentage (DOP), Critical Value Approach (CVA) and Sufficiency Range Approach (SRA) were used. In the CND method, a determination coefficient measured which is considered as the relative superiority of this method to the others. Generally, through the CND method, a correct perception on nutritional status of plantsmay be obtained.
Materials and Methods: The nutritional status of orange orchards, Valencia cultivar, in south of Fars province (Darab town) was studiedusing the compositional nutrient diagnosis and multivariate statistical analysis methods. For this, 80 orange orchards, Valencia cultivar were selected and 30 trees in each orchard were signed. Plant samples were taken from the selected trees in the proper session and concentration of N, P, K, Ca, Mg, Mn, Zn, Fe, Cu and B weremeasured using the standard methods. Then the average yield was measured atharvest. Based on the CND method, total concentration of the nutrients in the plant was considered as a variable (Sd) plus a residual portion (Rd) that "d" is defined as the number of nutrients in the equation and Rd is defined as the residual value. Which sum of the equation equals 100 and it is based on percent. The residual/un measured nutrients and estimated by using the equation of " Rd = 100- (N+P+K+…)". Thereafter, by using the standard equations, which they were perfectly explained and presented in the material and methods section, the geometric mean of nutrients, nutrients index, nutrient balance index, and average yield and finally the reference norms were determined. In addition to the CND method, by using the Multivariate Statistical Analysis and PrincipalComponent Analysis methods, the effective and important nutrients in the yield were determined and also, ability of the CND method was evaluated. The SPSS software was used for variance analysis the data.
Compositional nutrient diagnosis (CND) analysis and multivariate analysis methods are used to study the nutritional diagnosis of Valencia orange orchards in south of Fars province. 80 valencia orange orchards were selected in the region and in each of them, 30 uniform trees were marked and sampled were taken in proper time and referenced method. Leaf elemental compositions and mean yield also were measured from selected trees for each orchard. Data analysis divided all orchards into two low and high yield groups.
Results and Discussion: The results showed that 11 orchards were as high yielding group and 69 orchards were as low yielding group and the average of optimum yields, 113 Kg tree-1, was determined as the yield goal. By using the average of measured nutrients norms for the high yielding community the concentration of the 10 studied elements was obtained which comprised: N 3.00± 0.18; P 0.17± 0.01; K 1.37± 0.12; Ca 3.32± 0.78; Mg 0.36±0.07; Mn 23± 3.35; Zn 17.3± 2.3; Fe 75± 7.3; Cu 7.81± 1.44; B 76± 19.4. Through comparison with the obtained reference norms of optimum yielding orchards, more than 50% of the studied orchards had lower N, Ca and Mn content than the obtained norm and B concentration in the high yielding group was more than 50% less than the low yielding group. Generally, the results of Multivariate Statistical Analysis and PrincipalComponent Analysis showed that N, Ca, Fe and Zn had the highest effect in changes of yield.
Conclusion: Resultsof this work showed that 13% of the studied orchards were in the high yielding group and 86% of themwere in thelow yielding group which shows the imbalance nutritional condition in the studied region. The positive effect of N and Ca on the yield may be due to the dilution effect which these nutrients can reduce the B toxicity. Abundance of Mn deficiency in the studied orchards may be due to the high concentration of Zn and Fe in the plants and antagonistic relations may be considered as the main reason. Multivariate statistical analysis methods may be used as an important tool to study the nutritional conditions of plants. Dominant percentage of the studied orchards showed low yield which may be due to the B toxicity which probably N and Ca application may be alleviated the negative effect of this element.
H. Asadi Rahmani; A. Lakzian; J. Ghaderi; P. Keshavarz; H. Haghighatnia; K. Mirzashahi; M. R. Ramezanpour; A. Charati Arayi; A. Mohammadi Torkashvand
Abstract
Intoduction: Plant growth promoting rhizobacteria (PGPR) are a diverse group of bacteria consisting different species like Pseudomonas, Azotobacter, Azospirillum, Flavobacterium, Bacillus and Serratia with ability of enhancing plant growth and yield by different mechanisms. Flavobacteria are aerobic, ...
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Intoduction: Plant growth promoting rhizobacteria (PGPR) are a diverse group of bacteria consisting different species like Pseudomonas, Azotobacter, Azospirillum, Flavobacterium, Bacillus and Serratia with ability of enhancing plant growth and yield by different mechanisms. Flavobacteria are aerobic, gram negative, rod shape bacteria with more than 100 species living in different habitats ranging from soil and water to the foods. There are reports indicating that Flavobacteria are of dominant rhizosphere bacteria with beneficial effects on agricultural crops. Studies in Iran showed that six species of Flavobacterium were isolated and identified from rhizosphere of wheat. The aim of this study was to evaluate the effect of four strains of Flavobacterium on growth and yield of wheat under field conditions.
Materials and Methods: In this study four strains of Flavobacterium F9, F11, F21 and F40 were used. Bacterial strains were propagated in liquid NB growth medium and were used in field experiments. Fields were prepared in Khorasan Razavi, Khuzestan, Fars, Mazandran and Kermanshah and wheat seeds were inoculated with strains and sowed in a randomized complete block design (RCBD) with five treatments (four strains and a un-inoculated control) with four replications. Wheat varieties were Pishtaz in Khorasan and Fars, Marvdasht in Kermanshah, Chamran in Khuzestan and Milan in Mazandaran. Chemical fertilizers were used based on soil analysis. The rate of inoculation was 10 ml of bacteria per kg of seed. Plants were harvested at the end of the experiment and seed yield, total shoot biomass, 1000-seed weight, plant height, number of panicles per m2, number of seeds per panicle and panicle length were measured. Data analysis was performed by SPSS software, and the means were compared at α꞊5% by Duncan test.
Results and discussion: Results of the study showed that bacterial strains increased growth and yield of wheat in all provinces. In Mazandaran, all strains promoted seed yield although the effect of F21 was not significant. F40 had the highest effect on factors measures in the study. In Khuzestan, inoculation had no significant effect of seed yield production, although yield production was increased compared to control treatment. There was a similar trend regarding to other factors. In Khorasan, all factors were increased except for seed yield and 1000-seed weight due to inoculation with Flavobacterium strains. In Fars, inoculation with strain F40 significantly increased seed yield production by 11.5% compared to control treatment. In Kermanshah, seed yield, total biomass and plant height were significantly affected by inoculation with bacterial strains. Results showed that strain F40 was the most effective strain to increase yield of wheat. This study showed that Flavobacterium as a PGPR bacteria is able to positively affect the growth of wheat in Iran. This is in agreement with experiments in other parts of the world. In Khuzestan, bacteria were not effective on growth of wheat probably due to high soil temperature in this province compared to other provinces.
Conclusions: This study revealed that Flavobacteria are present in rhizosphere of wheat in Iran and could improve growth characteristics and yield of wheat in field experiments. Finally, strain F40 was the superior strain which increased seed yield by 15 % compared to control treatment.