M. Hagh Bahari, R. Seyed Sharifi,
Volume 5, Issue 2 (7-2014)
Abstract
In order to study of quantitative and qualitative yield, chlorophyll content and some growth indices of wheart (Triticum aestivum L.) in response to seed inoculation with plant growth promoting rhizobacteria (PGPR) at different levels of soil salinity, a factorial experiment based on randomized complete block design with three replications was conducted at Research Greenhouse of Faculty of Agriculture, University of Mohaghegh Ardabili, Ardabil, in 2011. Experimental factors were soil salinity at four levels (0, 15, 30 and 60 Mm as Nacl) and seed inoculation with PGPR in four levels (no inoculation as control, seed inoculation with Azotobacter chrocoocum strain 5, Azospirillum lipoferum strain OF, Pseudomonas putida strain 186). Comparison of means showed that in soil salinity conditions, grain yield per plant, number of grain per spike, grain 100 weight, spike length and root weight increased due to seed inoculation with PGPR compared to without seed inoculation. Investigation of total dry matter accumulation indicated that in all treatment combinations, it increased rapidly until 85 days after sowing. From 85 days after sowing till harvest time, it decreased due to increasing of competition, shedding and aging of leaves. In all treatment combinations, the highest grain yield and total dry matter accumulation per unit area was obtained in treatment combination of seed inoculation with Azosperilium × no soil salinity and the lowest amount was in the highest level of soil salinity × no seed inoculation. Similar trend was obtained in crop growth rate and relative growth rate. Hence, the results of this study showed that in order to increase the quantitative and qualitative yield, chlorophyll content and some other growth indices such as total biomass, crop growth rate and relative growth rate of wheat in soil salinity conditions, it could be suggested that wheat seed inoculation with Azospirillum be applied
H. Nejati Sini, R. Barzegar, S. Soodaee Mashaee, M. Ghasemi Ghahsare,
Volume 13, Issue 4 (3-2023)
Abstract
Abstract
Climate changes and agricultural practices such as excessive use of chemical fertilizers and pesticides have intensified the effect of abiotic pressures on crop productivity and have destroyed the ecosystem. One of the strategies to moderate these pressures is the use of organic fertilizers, mycorrhizal symbiosis and microbial inoculation. In order to investigate the effect of organic fertilizer, mycorrhizal fungi and Bacillus on the growth characteristics of bell pepper, an experiment was carried out as split plots on a randomized complete block design with the main factor of organic fertilizer at two levels (with and without organic fertilizer) and the secondary factor of biofertilizer treatments at four levels [arbuscular mycorrhizal (Rhizophagus irregularis + Funeliformis mosseae), Bacillus (B. subtilis + B. amyloliquefaciens)., mycorrhizal + bacteria mixture and control without inoculation] in three replications. Soil biological properties, nutrients uptake and growth characteristics and yield of the fruit were investigated after harvest. The results showed that the organic fertilizer and mycorrhizal fungi application increased the shoot dry weight (10.3% and 17.4%, respectively) and fruit yield (11.5% and 19.9%, respectively) compared to the control. The highest microbial population (1.1 × 107 CFU g-1) and R/S ratio (110.0) were obtained in the organic fertilizer application treatment with mycorrhizal inoculation. Mycorrhizal symbiosis with organic fertilizer application improved the uptake of nitrogen (20.6%), phosphorus (46.8%), iron (35.6%) and zinc (57.2%) compared to the control, and potassium uptake was improved by Bacillus treatment as compared to the control, it increased by 22.3%. In general, the combination of organic fertilizer and mycorrhizal fungi seems to be suitable for greenhouse bell pepper cultivation.
Background and Objective: Global agriculture faces various problems such as producing food for about 8 billion people by the middle of the 21st century. At the same time, people are struggling with economic conditions and malnutrition, as well as fierce competition for natural resources and climate change (4). Use of chemical fertilizers and pesticides has led to various environmental problems around the world. Organic farming (and the use of organic and bio-fertilizers) is a holistic development method that improves environmental sustainability, habitats, biogeochemical cycles and soil biological activity without the use of conventional fertilizers or pesticides (2). Mycorrhizal fungi have a significant environmental impact by improving soil quality such as soil biomass, structure and aggregation (1). Beneficial rhizosphere microorganisms that play a role in promoting plant growth can directly or indirectly promote plant growth. In this research, bell pepper plant was used, which is one of the most important fruit vegetables, that plantation area and its consumption are increasing (3). This research seeks to understand the relationship between mycorrhizal fungi and Bacillus bacteria with or without the use of organic fertilizers and their effect on the bell peppergrowth and nutrients uptake under greenhouse conditions.
Methods: This research was carried out as split plots on a randomized complete block design with the main factor of organic fertilizer at two levels (with and without organic fertilizer) and the secondary factor of biofertilizer treatments at four levels [arbuscular mycorrhizal (Rhizophagus irregularis + Funeliformis mosseae), Bacillus (B. amyloliquefaciens + B. subtilis), mycorrhizal + bacteria mixture and control without inoculation] in three replications. Organic fertilizer with the origin of decomposed animal manure was added in the rate of 3 kg m-2 to the bed soil in the main plots. Arbuscular mycorrhizal inoculum was prepared from Pishtaz Varian Biotechnology Company, and was added to planting hole in 10 grams (20 spores per gram) during seedling plantation. Pepper seedlings were placed in a suspension containing Bacillus bacteria (two liters containing 108 bacteria cells per liter) for 25 minutes and then planted in the greenhouse bed (1). Soil biological properties, nutrients uptake, growth characteristics and yield of the fruit were investigated after harvest.
Results: The results showed that the organic fertilizer and mycorrhizal fungi application increased the shoot dry weight (10.3% and 17.4%, respectively) and fruit yield (11.5% and 19.9%, respectively). The highest microbial population (1.1 × 107 CFU g-1) and R/S ratio (110.0) were obtained in the organic fertilizer application treatment with mycorrhizal inoculation. Plants inoculated with mycorrhizal fungi and without organic fertilizer had the highest microbial inoculation efficiency (22.73%), which showed a significant difference with the plants inoculated with Bacillus bacteria (2.23%). Mycorrhizal symbiosis with organic fertilizer application improved the uptake of nitrogen (20.6%), phosphorus (46.8%), iron (35.6%) and zinc (57.2%) compared to the control. The potassium uptake was improved by Bacillus treatment as compared to the control (i.e., it increased by 22.3%). In general, the combination of organic fertilizer and mycorrhizal fungi seems to be suitable for greenhouse bell pepper cultivation.
Conclusions: Arbuscular mycorrhizal fungi symbiosis with plant is the best biological relationship that improves the growth and productivity of plants. It plays a significant role in increasing yield and improving fruit ripening in bell pepper production. Overall, the effect of organic fertilizer and microbial inoculation with mycorrhizal fungi and Bacillus bacteria on the growth of bell pepper showed that the application of these treatments had a significant effect on the most of the measured characteristics and increased these traits except for plant height.
References:
1. Kumari, R., Bhatnagar, S., Deepali, N, Mehla, N, Vashistha, A. 2022. Potential of organic amendments (AM fungi, PGPR, vermicompost and seaweeds) in combating salt stress- a review. Plant Stress 6: 100111. https://doi.org/10.1016/j.stress.2022.100111.
2. Lobley, M., Butler, A., Reed, M. 2009. The contribution of organic farming to rural development: an exploration of the socio-economic linkages of organic and non-organic farms in England. Land Use Policy 263: 723–735.
3. Prasad, M., Srinivasan, R., Chaudhary, M., Choudhary, M., Jat, L.K., 2019. Plant growth promoting rhizobacteria (PGPR) for sustainable agriculture: perspectives and challenges. In: Singh, A.K., Kumar, A., Singh, P.K. (Eds.), PGPR Amelioration in Sustainable Agriculture (Food Security and Environmental Management), pp. 129–157.
4. Zhang, H., Zhu, J., Gong, Z., Zhu, J.K., 2022. Abiotic stress responses in plants. Nature Reviews Genetics 23(2): 104–119.
