F. rejali; A. Esmaelzad; K. Saghafi; V. hemati
Abstract
Introduction: Biofertilizers have been identified as alternative to chemical fertilizers to increase soil fertility and crop production in sustainable farming systems. One of the most useful kind of biofertilizers include plant growth promoting rhizobacteria (PGPR). Azospirillum is an associative rhizobacteria ...
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Introduction: Biofertilizers have been identified as alternative to chemical fertilizers to increase soil fertility and crop production in sustainable farming systems. One of the most useful kind of biofertilizers include plant growth promoting rhizobacteria (PGPR). Azospirillum is an associative rhizobacteria which can be very useful for plants such as wheat. It can help plant by fixing nitrogen through biological way, causing root development, plant strength improvement in primary phases, causing germination percent increment, improving plant tolerance in stress situations (drought, salinity, soil compaction and pathogens), secreting plant promoting hormones like cytokinin, Oxin and finally yield increment will be observable. Modern agriculture largely relies on the extensive application of agrochemicals, including inorganic fertilizers and pesticides. Although pesticides are important, their effects on nontarget organisms are of great concern because this poses a risk to the entire ecological system. The fungicides may also adversely affect the soil microflora, especially the types of microorganisms that can applied to seeds as bacterial inoculants. Considering useful effects of plant growth promoting rhizobacteria especially Azospirillum on Wheat, this study was done in order to survey interaction effects between fungicide and available biofertilizers in Iran market.
Materials and Methods: Effect of carboxin tiram in 2 levels (applied, non-applied) as fungicide, on efficacy of wheat plant (Chamran Cultivar) and final crop yields under association conditions with 5 Azospirillum species (A.brasilense, A.lipoferum, A.halopraeferense, A.irakense, A.sp) using powdery and liquid formulation were studied in a greenhouse test for four months in Soil and Water Research Institute.At first some properties of used soil, including soil texture, pH, EC,organic carbon and available soil K, P, Fe, Zn, Mn and Cu were measured by laboratory methods.Nutrient Broth medium were used for bacterial inoculum production with 108 bacterial cound per ml in final suspention. Using factorial experiment in a Completely Randomized Design (CRD), 2 bacterial inoculants factors (5 inoculation level and a non-inoculation level), CarboxinThiram fungicide levels (applied, non-applied) and two inoculants formulations (liquid and powdery) with four replicates per treatment and a total of 96 experimental units (pots), the most effective contribution of different species of Azospirillum bacteria with Chamran wheat varieties were evaluated in the presence of the fungicide. Studied Parameters included number of tillers, node interface, flag length, number of grains per spike, grain weight per spike, shoots wet weight, 1000 grain weight and shoot dry weight of wheat plant. Data were analyzed with SASS and Excel softwares. The comparison was done by Tukey test.
Results and Discussion: Regarding ANOVA table (table 2), liquid and powdery formulations of Azospirillum with different species had significant effect on 8 of 11 studied traits including number of tillers, plant hight, spike length, node interface, flag length, number of spikes per square meter , grain weight in spike, shoot wet weight, shoot dry weight. Fungicide had effect on 2 traits such as number of grain per spike and grain weight spike independently. Bacteria and fingicide interaction had significant effect on number of tillers, node interface, flag length, number of grain per spike, shoot dry weight (p< 0.01) and shoot wet weight (p< 0.05).
Numeric comparsion between similar treatments in presence and absence of fungicide, it can be concluded that although fungicide presence had no significant positive effectson studied traits, it did not have any negative effects eigther.Even it could increase traits quantity by affecting on bacteria. Also, regarding to Table 5, comparing fungicide effect on bacteria with studied trait in two formulations, it can be concluded that fungicide presence with bacteria was effective on quantity of some trait in powdery formulation and some in liquid formulation.These findinds may be the result of fungicide effects in controlling soil born pathogens in compatable treatments with used bacterial inoculums.
Conclusions: As final result, using A.lipoferum with both formulations and A.halopraeferense with powdery formulation, because of high compatibility with carboxin thiram fungicide can be advised in case of fungicide application. This advice can have good effects on functional traits such as number of tillers, grain weight in spike and shoot dry weight.To consider the effects of environmental conditions on the final results we propose to do this experiment in field scale in some Iranian provinces with different climatic conditions.The use of different concentrations of carboxin tiram and also different kinds of PGPR and other fungicides must be consider in future experiments.
M. Jiriaie; E. Fateh; A. Aynehband; E. Sepehr
Abstract
Introduction: Providing the nutritional requirements of agricultural crops by non-chemical resources is a new approach in the organic farming that has attracted the attention of both the researchers and the consumers in recent years. Therefore, it is highly important to find new fertilizer resources ...
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Introduction: Providing the nutritional requirements of agricultural crops by non-chemical resources is a new approach in the organic farming that has attracted the attention of both the researchers and the consumers in recent years. Therefore, it is highly important to find new fertilizer resources that are both economically able to provide the nutritional needs of the crop plants and have no adverse effects on the consumers and the environment.
Materials and Methods: With this approach, an experiment was conducted in the research station of Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on randomized complete blocks design with three replications. The treatments including Mycorrhizal fungi in three levels (i.e. no use of strain; use of Glomus intraradices strain; and use of Glomus mosseae strain), bacteria Azospirillum lipoferum in two-levels (i.e. non-inoculated and inoculated) and wheat cultivars in three levels (i.e. Chamran; Dena; and Behrang). The measured parameters include the concentration of macronutrients (i.e. nitrogen, phosphorus and potassium) and some micronutrients (i.e. zinc, iron and manganese) in two part seed and the root of wheat.
Results and Discussion: Surveying the elements content in the root and the grain indicated a significant and positive effect of the use the Azospirillum and Mycorrhiza to improve the concentration of the elements in wheat cultivars. However, the simultaneous use of these microorganisms led to an increase of the effects of their application on their assessed traits.Finally the highest concentration of N (2.21 present), P (0.50 present) and Fe (33.88 mg.kg-1) were observed in the grain; the highest concentration of K (0.93 present and 0.54 present) and Mn (43.11 and 23.63 mg.kg-1) were observed in the grain and root, respectively. Moreover, the highest concentration of Zn in the root (19.70 mg.kg-1) was obtained from inoculation of C.V Dena seeds with Azospirillum and the use of G. mosseae. Also, in the general case of Mycorrhiza fungi use (between 6 to 20 present) and seed inoculation with Azospirillum lipoferum (between 8 to 25 present), the improved nutrient content in the seeds as well as greatest impact of Mycorrhiza use is in increasing the content of the grain Zn (20 present) and the lowest effect of Mycorrhiza using is in increasing the nitrogen content in seed (6 percent). Considering the elements content in the grain, the use of bacteria also showed that the greatest impact on increasing the use of bacteria Azospirillum lipoferum is in increasing the iron content in seeds (25 present) and the least impact of the use of Azospirillum lipoferum is in increasing the seed’s manganese (8 present). Moreover, the use of Mycorrhiza fungi (between 7 and 23 present) and seed inoculation with Azospirillum lipoferum (4 to 16 present) improved the contents of nutrients in wheat roots compared with the control group. Here, too, the greatest impact for Mycorrhiza application was in increasing the content of the Zn in the root (23 present) and the lowest effect of Mycorrhiza application was in increasing the potassium content in the root (7 percent). Moreover, considering the elements content in the roots in the case of being treated with Azospirillum lipoferum, the results showed that upon increasing the use of bacteria, the greatest impact of Azospirillum lipoferum in increasing elements content in the roots was an increased iron content in the root (16 present) and the minimum effect of the bactericidal application was in increasing the potassium root (4 present). Comparing the two species of Mycorrhizal fungi that have been used in the experiment, although application Glomus intraradices showed satisfactory results, the use of the species Glomus mosseae to increase the content of the element in seeds and roots has had a greater role. Moreover, the combined effects of these microorganisms have not only had an antagonistic effect of reducing the amount of content, they have also been more effective than being applied separately (between 7 and 12 present).
Conclusion: Generally associated with most of the measured elements, the treatment of seed inoculation with Azospirillum lipoferum and usage of Glomus mosseae in Dena cultivar that was a durum wheat, showed the highest concentration of the mentioned elements in the roots and seeds. Probably this has been due to the smaller grains in Dena than the other cultivars, which led to an increase in the ratio of the elements in the grain. Therefore, it seems that the use of the biofertilizers can be the perfect solution to eliminate the nutritional requirements of wheat. Moreover, it has the very important effect of the enrichment of this crucial product in the people’s dietary patterns in this country with the required elements.
Keywords: Azospirillum, Nutrition, Wheat, Root, Elements concentration, Mycorrhiza
