Bacterium Azotobacter Research Articles

The balance of nitrogen forms and number of microorganisms of the nitrogen cycle in vermicomposts based on leaf litter and cow manure

The processes of nitrogen transformation in the vermiculture system by Eisenia fetida using cow manure and leaf litter (poplar with small birch addition) have been investigated. Vermicomposting was carried out for five months in half-cubic meter wooden containers. The Kjeldahl method and potentiometry determined the total nitrogen, NH4 + and NO3- content in vermicompost. The total nitrogen content in cow manure was 1.83%, in leaf litter - 0.73%. The nitrate and ammonium content in non-composted leaf litter was 351 and 7.3 mEq/kg of dry matter, respectively. The nitrate and ammonium content in non-composted cow manure was 18.2 and 22 mEq/kg, respectively. Both investigated substrates of vermicomposting did not influence total nitrogen content. In cow manure-based vermicomposting system, the ammonium amount decreased by 5.3 times, while the concentration of nitrates increased by 6.5 times. In the leaf litter-based vermicomposting system, the ammonium amount increased by 2.9 times, and the amount of the nitrate increased by 1.6 times. The Azotobacter bacteria actual activity in both vermicomposts was close to 100%. The sum of nitrogen cycle microorganisms in manure vermicompost was 2.4 times higher than in leaf litter vermicompost.

Toxicity and activity inhibition of metal-organic framework MOF-199 to nitrogen-fixing bacterium Azotobacter vinelandii

Metal-organic framework (MOF) materials with fantastic properties have found important applications in various areas. Learning the lessons from plastics and microplastics, it is urgent to investigate the environmental impacts of emerging materials to avoid potential pollution. However, the environmental toxicity and risks of MOF materials are seldom reported. Herein, we studied the toxicity and activity inhibition of MOF-199 to nitrogen-fixing bacterium Azotobacter vinelandii. MOF-199 significantly suppressed the growth of A. vinelandii and led to cell death at 40 mg/L. MOF-199 penetrated the cell wall and induced the shrinking of bacterial cells. MOF-199 reduced the nitrogen fixation activity of A. vinelandii at 40 mg/L by decreasing the gene nifH levels and inhibiting the Ca2+Mg2+-ATPase activity, which was further confirmed by the changes in oxidative phosphorylation related genes. Complete growth inhibition and activity loss of A. vinelandii occurred at 60 mg/L of MOF-199. The toxicological mechanism of MOF-199 to A. vinelandii was assigned to the oxidative stress, which occurred at 20 mg/L and higher. Both Cu2+ release and particulates themselves contributed to the toxicity of MOF-199 to A. vinelandii. These findings highlighted the environmental hazards and risks of MOF materials to nitrogen-fixing bacteria and nitrogen fixation in the biogeochemical cycle.

Accumulation of beneficial bacteria in the rhizosphere of maize (Zea mays L.) grown in a saline soil in responding to a consortium of plant growth promoting rhizobacteria

PurposeSalt stress reduces plant growth and is now becoming one of the most important factors restricting the agricultural productivity. Inoculation of plant growth-promoting rhizobacteria (PGPR) has been shown to confer plant tolerance against abiotic stress, but the detailed mechanisms of how this occurs remain unclear and the application effects in different reports are unstable. In order to obtain a favorite effect of PGPR inoculation and improve our knowledge about the related mechanism, we performed this study to analyze the mechanism of a PGPR consortium on improving the salt resistance of crops.MethodsA region-specific (Saline land around Bohai Sea in China) PGPR consortium was selected that contains three strains (Pseudomonas sp. P8, Peribacillus sp. P10, and Streptomyces sp. X52) isolated from rhizosphere of Sonchus brachyotus DC. grown in a saline soil. By inoculation tests, their plant growth-promoting (PGP) traits and ability to improve the salt resistance of maize were investigated and shifting in rhizosphere bacterial community of the inoculated plants was analyzed using the high-throughput sequencing technology.ResultsThe three selected strains were salt tolerant, presented several growth promoting properties, and inhibited several phytopathogenic fungi. The inoculation of this consortium promoted the growth of maize plant and enriched the beneficial bacteria in rhizosphere of maize in a saline soil, including the nitrogen fixing bacteria Azotobacter, Sinorhizobium, and Devosia, and the nitrification bacteria Candidatus Nitrososphaera, and Nitrosovibrio.ConclusionsThe bacterial consortium P8/P10/X52 could improve plant growth in a saline soil by both their PGP traits and regulating the rhizosphere bacterial community. The findings provided novel information about how the PGPR helped the plants in the view of microbiome.

Bio-fertilizers\u2019 protocol for controlling root knot nematode Meloidogyne javanica infecting peanut fields

BackgroundPlant parasitic nematodes create serious threat to crop production. In Egypt root knot nematode, Meloidogyne spp. has been considered to be a limiting factor in the production of most crops of which the Peanut (Arachis hypogaea L.) is an important legume and oil crop. Therefore, management of root knot nematodes Meloidogyne spp. is an obligatory challenge. Microbial organisms are extensively used as eco-friendly tools for controlling plant parasitic nematodes as alternative to chemical nematicides. The effectiveness of the commercial bacterial bio-fertilizers NPK containing Bacillus polymyxa, B. circulance, B. megaterium, Pseudomans spp.; the nitrogen fixative bacteria Azotobacter chroocoocum and the bacterial isolate NRC211 were evaluated against the root knot nematode, Meloidogyne javanica infecting peanut plants under field conditions. Identification of the bacterial isolate was made through PCR amplification and sequencing of 16S rDNA gene.ResultsSequencing of 16S rDNA gene revealed that the bacterial isolate NRC211 had 100% similarity with Bacillus wiedmannii strain FSL W8-0169 16S ribosomal RNA. This Bacillus was recorded for the first time under accession number LC626774 on GenBank data base as B. wiedmannii NRC211. Recorded data revealed that all the tested treatments whether single or combined in soil naturally infested with M. javanica, resulted in variable significant reduction in the nematode reproductive parameters with a considerable increase in crop production and oil content of peanut plant. These results were improved by increasing the frequency of application of the bio-agents. In this respect the repeated combined treatment of A. chroococcum and B. wiedmannii NRC211 treatment overwhelmed all other treatments in decreasing nematode reproductive parameters with percentage reductions of 94.8, 79.0 and 80.1% in M. javanica juveniles in soil, galls and egg masses, respectively. This was associated with slight increase in peanut oil content than the untreated control. The repeated combined treatment of NPK plus A. chroococcum produced the highest increase 608.7%, and 72.7% in crop production and plant growth parameters, respectively than the control. While, the oil content in this treatment was increased up to 47.4 g/kg.ConclusionIt was concluded that B. wiedmanni NRC211 is an eco-friendly bio agent that can be applied with other commercial microbial bio-fertilizers in bio-integrating programs for controlling M. javanica infecting peanut plants.

Microbiological integration for qualitative improvement of vermicompost

Purpose This study was carried out to assess the effect of integrating microbiological fortification with vermicomposting process on biofertilizing quality of vermicompost as well as improvement of the availability of nitrogen and phosphorus in the product. Method A mixture of cow dung and vegetable market waste (1:1) was used for vermicomposting with Eisenia foetida as the decomposer earthworm @ 10 no.of worm kg-1 substrate. Nitrogen fixing and phosphate solubilizing bacteria (NFB and PSB)Azotobacter chroococcum and Pseudomonas fluorescens were integrated with this composting process at varying doses viz. 0,5 and 10 g kg-1 substrate under different combinations. Changes in the population of these two bio-fertilizing microorganisms and the availability of relevant nutrients in the substrates were monitored periodically to assess the behaviors of these microorganisms and their effects on the produced vermicompost. Results All the inoculations resulted in substantial increments in population of both NFB and PSB over the control. However, the increments were more prominent for NFB than the PSB. Significant increments in the amount of mineralized nitrogen and solubilized phosphate over the control were observed in almost all the treatment combinations. Conclusion Integration of nitrogen fixing and phosphate solubilizing bacteria with vermicomposting process resulted in substantial enrichment of the product. This benefit was observed not only in terms of increased availability of the two major plant nutrients of concern viz. N and P, but also in significant improvement in the population of the inoculated microorganisms turning the product into a potential source of bio-fertilizers.

A Low‐Potential Terminal Oxidase Associated with the Iron‐Only Nitrogenase from the Nitrogen‐Fixing Bacterium Azotobacter vinelandii

Modern agriculture depends on nitrogenous fertilizer produced by the Haber-Bosch process, but fertilizer use is polluting and its production needs large amounts of methane and emits carbon dioxide. To minimize nitrogen pollution and to reduce the need for fertilizer, there is interest in expressing functional nitrogenase in crop plants, either directly or in prokaryotic symbiotes. The iron-only alternative nitrogenase is a good candidate for expression, because it requires fewer genes than the more common MoFe nitrogenase. Nitrogenases are inactivated by oxygen, so understanding and overcoming this inhibition will be important for heterologous nitrogenase expression. The Anf3 protein in the bacterium Rhodobacter capsulatus is essential for diazotrophic (i.e. nitrogen-fixing) growth with the iron-only nitrogenase, but its enzymatic activity and function are unknown. We have biochemically and structurally characterized Anf3 from the model diazotrophic bacterium Azotobacter vinelandii. Determining the Anf3 crystal structure to atomic resolution, we observed that it is a dimeric flavocytochrome with an unusually close interaction between the heme and the FAD cofactors. Measuring the reduction potentials by spectroelectrochemical redox titration, we observed values of -420 ± 10 mV and -330 ± 10 mV for the two FAD potentials and -340 ± 1 mV for the heme. We further show that Anf3 accepts electrons from spinach ferredoxin and that Anf3 consumes oxygen without generating superoxide or hydrogen peroxide. The combination of the biochemical, electrochemical, and structural results show that Anf3 catalyzes the reduction of oxygen to water. We expect the catalytic mechanism to be similar to that of other heme-containing oxidases because four electrons can be accumulated: two on the FAD and two on the heme, and then rapidly donated to the bound oxygen for its four-electron reduction to water. We predict that Anf3 protects the iron-only nitrogenase from oxygen inactivation by functioning as an oxidase in respiratory protection, with flavodoxin or ferredoxin as the physiological electron donors. Anf3 is therefore a promising candidate to enhance functional nitrogenase expression in heterologous systems.

The Effect of Biological Inoculation of Azotobacter chrococcum and Glomus mosseae on Growth and Yield of Zea mays L. under Different Levels of Water Stress

This study aimed to investigate the effect of inoculation with the bacteria Azotobacter chrococcum and the fungus Glomus mosseae on the growth and yield of Zea mays L. variety (Baghdad 3) under different levels of water stress. The field trial was conducted in the fall season of 2020 in Diwaniyah Governorate-Afak county fields. The experiment was designed according to the Randomized Complete Block Design (R.C.B.D) design with three replications. The treatments were distributed randomly. Three levels of irrigation were used in the experiment, namely (I4) irrigation every four days, (I7) irrigation every seven days, (I10) irrigation every ten days, and inoculation levels. Biological inoculation with the bacteria at two different levels (B1) inoculation with bacteria A-chrococcum, (B0) without inoculation. Fungal inoculation with G-mosseae at two inoculation levels (F1) and without inoculation with (F0). In addition to the overlapping treatment between fungus and (B1F1) bacteria. The treatments’ means were compared using the least significant difference (L.S.D) test at a probability level of 5%. The results present that the treatments inoculated with fungi or bacteria, or both, and for a seven-day irrigation period, significantly increased the values of the traits of (dry weight of the root mass, leaf area, chlorophyll concentration, and total yield). The highest means values were (5739) g.Plant−1, (18.04) cm2.plant−1, (58.93) SPAD, and (9.104) tons.ha−1, respectively, compared to the treatments (no application + irrigation every ten days) that gave (13.75) g.Plant−1, (2539) cm2.plant−1, (3.921) SPAD, and (29.07) tons.ha−1.

Toxicity and environmental impact of multi-walled carbon nanotubes to nitrogen-fixing bacterium Azotobacter chroococcum

With the large-scale production and wide applications of carbon nanotubes (CNTs), they are inevitably entering the environment and bringing unknown threats to environmental organisms. Nitrogen-fixing bacteria dominate 80% of the nitrogen fixation in nitrogen cycle. Herein, we investigated the toxicity and environmental impact of multi-walled CNTs (MWCNTs) to nitrogen-fixing bacterium Azotobacter chroococcum. MWCNTs slightly inhibited the growth of A. chroococcum and induced small increase of death rate at high concentrations. MWCNTs did not penetrate the cell walls of A. chroococcum and no cytoplasm loss was observed. MWCNTs were only observed surrounding the A. chroococcum cells. According to oxidative stress assays, MWCNTs induced meaningful oxidative damage at 0.5 mg/mL after 6 d exposure, but the oxidative damage diminished at 14 d. MWCNTs did not affect the nitrogen fixation activity of A. chroococcum and the soil nitrogen contents. Our findings provided the fundamental data for the environmental safety of CNTs to nitrogen-fixing bacteria.

Efficiency of the Complex Bacterial Preparation Azogran Application in Protecting Potatoes from the Colorado Potato Beetle Depending on the Stage of Its Development

The Colorado potato beetle (Leptinotarsa decemlineana Say) is a particularly dangerous potato phytophage. The aim of this work was to study the effect of complex granulated bacterial preparation Azogran and its components on the spread of the Colorado potato beetle in the potato phytocenosis. Methods. The study was carried out during potato of the Slavyanka variety growing under the conditions of small-plot and laboratory experiments. The complex granulated preparation Azogran was made on the basis of interaction of nitrogen-fixing bacteria Azotobacter vinelandii IMV B-7076, phosphate-mobilizing bacteria Bacillus subtilis IMV B-7023 and clay mineral bentonite. 1 g of the preparation contains more than 108 viable bacteria of each strain. The mass of 1 granule was 0.25 g. The effect of Azogran, its components and 4-hydroxyphenylacetic acid (4-HPAA), a metabolite of B. subtilis IMV B-7023, on the survival of Colorado potato beetle larvae was estimated in laboratory conditions. Results. It was shown that the use of the complex bacterial preparation Azogran, B. subtilis IMV B-7023 strain and its metabolite 4-HPAA in the potato phytocenosis significantly reduces the spread of the Colorado potato beetle imago, as well as the number of egg-laying on the leaf surface of plants. Treatment of eggs clutches of the phytophage with this preparation and its specified components significantly reduces the number of larvae on the leaves. Treatment of 1–4 stages larvae with solutions of 4-HPAA at a concentration of 0.5–50.0 μg/ml, as well as a suspension of B. subtilis ІМV В-7023 bacteria or their culture medium (without cells), leads to significant death of the larvae. Conclusions. The use of the complex bacterial preparation Azogran, as well as its component bacteria B. subtilis IMV B-7023 in the phytocenosis of potatoes stimulates plant growth, significantly reduces the spread of the Colorado potato beetle and the number of eggs clutches on the leaf surface. Treatment of Colorado potato beetle larvae of 1–4 stages of development with a suspension of B. subtilis IMV B-7023 bacteria, as well as their metabolite 4-HPAA leads to the death of more than 65% of larvae. The results obtained indicate that the use of the complex bacterial preparation Azogran is promising for potatoes growing.

Проблемы и перспективы вовлечения отходов обогащения полиметаллических и железных руд в биологическую консервацию

Ore enrichment waste is a fine material that poses a serious environmental problem. However, the high residual content of rare and precious metals, as well as valuable metalloids, determines the preservation of technogenic formations as secondary mineral raw materials. This dictates the search for environmentally safe conservation of waste before its subsequent development. This report focuses on reducing the phytotoxicity of waste and the use of bioagumentation - the introduction of exogenous plant matter and azotobacteria into the root layer, which contributes to the optimization of the mineral nutrition of phytoconservants. The article examines the physical and chemical parameters of polymetallic ore dressing waste before and after chemical reclamation, provides information on changes in the composition of watersoluble forms of metal elements (Fe, Mn, Al, Cu, Zn, Cd, Co, Ni), a decrease in the anionic content of the sulfate ion, and the appearance of hydrocarbonates. It is experimentally established that after chemical reclamation of spent slags, their viability for seedlings of oats and white mustard increases. After reclamation, there is an increase in their morphometric indicators. Mustard reacts especially positively to the decrease in acidity and mobility of metals. The dry weight of its seedlings increases-by almost 30% compared to the control. When mustard seeds are inoculated with a suspension of a live culture of the bacterium Azotobacter chroococcum, its roots elongate and their weight increases. It is shown that the growth of mustard roots is also activated on iron ore processing waste that is subject to forest reclamation. But in such conditions, vital azotobacteria exhibit a glow, especially intense in small sand fractions. Chemolumi-nescent reactions ensure the survival of azotobacteria in the development of free radical reactions caused by the residual content of magnetic iron and lignin in the habitat. The revealed features of the growth of oat and mustard seedlings, as well as azotobacteria on ore dressing waste, should be taken into account when developing technologies to increase the biogenicity of the waste surface in vivo, to argue for the use of bioagumentation in creating technologies for environmentally safe waste conservation without involving the fertile soil layer - an irreplaceable natural resource.

Effects of Nitroxin and arbuscular mycorrhizal fungi on the agro-physiological traits and grain yield of sorghum (Sorghum bicolor L.) under drought stress conditions.

The use of bio-fertilizers in agro-ecosystems is considered to have the potential to improve plant growth in extreme environments featuring water shortages. However, while arbuscular mycorrhizal fungi (AMF) and bacteria bio-fertilizers have been used in other plants to enhance stress tolerance, little is known about their symbiotic effect on sorghum (Sorghum bicolor L.) growth under drought stress conditions. Therefore the aim of this study was to investigate the inoculation of sorghum with Nitroxin and Glomus mosseae and their interaction effects on the agro-physiological characteristics and grain yield of sorghum under drought stress conditions. Nitroxin is a bio-fertilizer that consists of a mixture of Azospirillum and Azotobacter bacteria. The results showed that co-inoculation of sorghum seeds with Nitroxin and AMF improved the chlorophyll (a, b and total) content, soluble proteins, water use efficiency) WUE(, relative water content (RWC), nitrogen (N) content in the plant, AMF spore density, proline content, grain yield, panicle length, the number of panicles per plant, grain number per panicle, 1000-grain weight and decreased the electrolyte leakage and water saturation deficit (WSD) in drought stress and non-stress conditions. Under drought stress conditions, there was a 27% increase in grain yield under the synergistic effects of bacteria and fungi compared to the non-application of these microorganisms. The results of this experiment show that Nitroxin and AMF bio-fertilizers can mitigate the negative effects of stress on plants in drought stress conditions by increasing the amount of photosynthetic pigments, soluble proteins and osmotic regulation and decreasing electrolyte leakage. We found that the combination of bacteria and AMF for sorghum growth and yield increment is a promising method to cope with the stress caused by drought.

Influence of heavy metals pollution on the formation of microbial community in gray forest soil

The state of microbial communities in gray forest soil contaminated with heavy metals at a dose of 5, 10, 100 MPC, in the presence and absence of vegetative phytosynesis (corn) has been investigated in model experiments. The protective function of the phytocenosis concerning several groups of microorganisms, in particular, azotobacter and polysaccharide-synthesizing bacteria, has been shown. The number of azotobacter in the rhizosphere of plants exceeds the indices of soil without plants: in the control by 3.33%, at 5 MPC – 36.6, at 10 MPC - by 95.6%. The indicative function of azotobacter has been confirmed concerning soil pollution with heavy metals. The number of azotobacter is decreased with increasing the pollutant dose in the soil without plants: at 5 MPC - by 2.64 times, at 10 MPC - by 6.67 times, the corresponding indicators for plants rhizosphere are 2.05 and 3.52 times. Azotobacter is not detected by the method of overgrowing soil lumps at the maximum level of soil contamination with heavy metals (100 MPC). The mycelial forms of microorganisms (micromycetes) are highly resistant to contamination with heavy metals that have been confirmed. The activity of mineralization of organic substances, including hummus, is decreased with the increasing of pollutant dose in the soil has been shown. The pedotrophy index decreases at 5 MPC by 3.16%, at 10 MPC - 30,9, and 100 MPC - by 46.8% in soil without plants. Similar numbers for variants with plants fluctuate between 14.2 and 105.4%. The conclusion about a lesser susceptibility to microbial mineralization of complexes of humic acids and heavy metals has been confirmed. With an increase in the dose of the pollutant, the activity of humus mineralization decreases in soil without plants: at 5 MPC - by 16.7%, at 10 MPC – 12.6, at 100 MPC - by 74.7%; with plants: at 5 MPC - by 14.3%, at 10 MPC – 8.33, at 100 MPC - by 113.7%. It is also drawn attention to the fact that the activity of humus mineralization in the soil rhizosphere is lower than in the soil without plants. In our opinion, the reason for this is the presence of easily utilized substrates in the composition of plant root exudates. It makes the mineralization of hard-to-reach humus molecules inappropriate.

FEATURES OF APPLICATION OF BIOPREPARATIONS FOR CULTIVATION OF OYSTER MUSHROOMS ON STRAW SUBSTRATE

The world’s population consumes a significant amount of mushrooms each year. Beginners in mushroom growing are considered to be the Chinese, who at the beginning of our era learned to grow different species of basidiomycetes. Today, Ukraine has a significant potential for the development of mushroom growing: there are the necessary raw materials for substrates and still unoccupied premises. Research institutions preserve a unique collection of high-yielding strains, and specialized laboratories produce high-quality seed mycelium. The article is devoted to the study of the influence of biologicals on the productivity of oyster mushrooms of the common strain K-12 during intensive cultivation on a straw substrate. Based on research, it is established that the use of biologicals as an adjunct to the substrate affects the growth processes of the fungus. Biometric indicators of fruit body weight with the use of azotophyte or phytocyde exceeded the indicators of fruit body weight grown on the substrate, where the biological product was not used by 2,0 g, and the diameter of the cap was inferior to 2,0 and 6,0 mm, respectively. Fungi obtained on the substrate without the use of the biological product were characterized by a shorter leg length compared to the variant using azotophyte by 3,0 mm, and exceeded the test value by 4 mm using phytocyde. From the use of azotophyte or phytocide, the diameter of the stem of the fruiting body decreases to 12,0-15,0 mm. Carrying out of timely agrotechnical actions promotes reception of a qualitative harvest of fruit bodies of an oyster mushroom. Before harvesting, the fruiting bodies were characterized by a typical shape and inherent color of the cap and were in technical maturity. The cap of the fruit body did not crack, was not damaged by pests, and its humidity was 65,0-68,0 %. The activity of the bacteria Azotobacter chroococcum and Bacillus subtilis has an effect on the productivity of strain K-12, they stimulate the formation of more primordia. With the use of Azotophyte or Phytocide, the yield increases by 22,0 and 18,0 %. The total yield of oyster mushroom consists of two waves of fruiting. The yield of the first wave of fruiting is 2,3 times higher than the yield of the second wave of fruiting. The use of Azotophyte helps to increase the yield of the first wave of fruiting fungus by 2,2 kg / 100 kg of substrate, and phytocide – by 1,8 kg / 100 kg of substrate. The use of Azotophyte or Phytocyde as an additive to the substrate is economically advantageous: the net profit increases by 32 and 24 %, and the level of profitability - by 1,2-1,1 times, respectively.

LEAF-FEEDING PROCESSING OF PLANTS OF THE TOMATILLO BIOPROOFICIANS UNDER THE CONDITIONS OF THE RIGHT-BANK FOREST-STEPPE OF UKRAINE

The article is devoted to the study of the effect of foliar treatment of Tomatillo plants with the use of drugs of bacterial origin. The paper scientifically substantiates the influence of biologicals on the morphological and biometric parameters of the plant. It was investigated that the emergence of seedlings in varieties Lichtaryk and Pineapple was observed for 7-8 days. After diving and two treatments of plants with drugs, their positive effect on the growth and development of Tomatillo, especially in the phase of budding, flowering and fruiting. A short period of bud formation on the plant was characterized by a variety of Tomatillo Lantern from the use of Biomag. Thus, the beginning of the formation of buds occurred on 66 days on the Lantern variety. A similar effect of the biological product was found during the flowering phase and fruit set. As a result of the activity of Azotobacter chorococum bacteria, the growth and development phases of the Lantern variety are accelerated by 1-3 days compared to the control variant. The use of biological products has had a positive effect on the biometric parameters of the plant. When using bacteria p. Saccharomyces, Azotobacter chroococcum, Paenibacillus polymyxa, Enterobacter nimipressuralis, plant height and stem diameter depended on the type of biological product used. The height of the plant ranged from 82,8 cm to 89,6 cm in the variety Lantern and from 86,8 cm to 91,3 cm in the variety Pineapple. As a result of spraying the plants with Azotobacterin or Rostmoment, the height of the Tomatillo plant exceeded the height of the plant of the variant where biological products were not used. In these variants, the excess of plant height relative to the control was 8,2% for the variety Lantern and 4,3 % for the variety Pineapple, respectively. The diameter of the stem was in the range of 1,9-2,0 cm. Due to the activity of the bacteria Azotobacter chroococcum, Paenibacillus polymyxa, Enterobacter nimipressuralis or yeast p. Saccharomyces and products of their metabolism, revealed a positive effect of biologicals on the increase in leaf area and dry matter content of the leaf. As a result of cultivation of the cultivar Lichtarik and application of Rostmoment or Biopolitsid the area of leaves was at the level of 79,5 thousand м2/ha and 77,6 thousand м2/ha. Growth moment, for the cultivation of the variety Lantern, helped to increase the dry matter content of the leaf by 16,4 %. Treatment of Lantern plants with liquid humus-based concentrate Humisol provided the highest weight of Tomatillo fruit, which was at the level of 8,4 g, and the use of Humisol or Rostmoment for growing varieties Lantern and Pineapple increases the diameter of Tomatillo fruit by 6,9-10,3 %. Humisol, due to humic and fulvic acids, natural phytohormones affects the growth processes of the plant more intensively, which provided in the formation of the largest mass of fruits and their diameter. High yield is characterized by the Tomatillo variety Lantern with five applications of Humisol or Biopolicide, where its value is 33,3 t/ha and 32,0 t/ha. Key words: morphological features, biometric indicators, tomatillo, fruit yield, marketability.

Study of the Impact of Organic Manures and Biofertilizers on growth of Phaseolus aureus Roxb.

Weed sare wild plants growing where they are not wanted, and they compete with the cultivated crop for nutrition. Though they are seen as agricultural waste throughout the year, they are rich sources of nutrients. They grow in abundance during the rainy season, but as the season ends these biomasses get wasted. In the present investigation, Tephrosia hamiltonii Drumm belonging to family Fabaceae, and Achyranthes aspera L. belonging to the family Amaranthaceae were used as a nutrient source to develop crop Phaseolus aureus Roxb. Weed manures, Vermicompost and Compost, were prepared by using weeds T.hamiltonii Drumm and A.aspera L. in 1:1 proportion. Chemical analysis of weed and weed manures were done before administering it into the soil. Neem cake was also used as one of the organic manures. In the experiment, a single dose of biofertilizers Azotobacter and Phosphate solubilizing bacteria were mixed with Weed Vermicompost, Weed Compost and Neem cake; and in one of the treatments, only biofertilizers were used indouble dose. Treatments were given to the crop as ATVB, ATCB, NCB, BioD, NPK, and Control in a randomized block design of experimental plot size 1.5X 1.5 m. The use of chemical pesticides or fertilizers was completely avoided except for NPK treatment plots. Single plant analysis of pulse crop P. aureus Roxb. was done. Observations were recorded in the forms of fresh weight and dry weight of root, stem, leaves, leaf (4th number), and legumes. Total fresh yield (kg ha-1), DM (kg ha-1) increase over control, and Nitrogen efficiency ratio were recorded. Results showed that %DM (an increase over control) and DM kg ha-1 recorded highest in ATVB treatment and the highest N efficiency ratio was in BioD. The present investigation emphasized reducing the input cost of the farm products along with protection of the environment and natural resources.

The Effect of Bioorganic Dosage with N, P Fertilizer on Rice Production of Sri Methods and Increased Nutrient Content of Paddy Soil Intensification

The System of Rice Intensification (SRI) operates under aerobic conditions so that helpful microbes are active and abundant. Effective N-fixing rhizobacteria and indigenous phosphate solubilizers Azotobacter and Pseudomonas grow well in the organic compost Bioorganic because it resembles their natural habitat. The purpose of this research is to find out the right dose of Bioorganic fertilizer and the most N and P doses needed to optimize the SRI method of rice crop production. This research uses a factorial randomized block design. The first factor is Bioorganic fertilizer dosage (1, 3, and 6) t ha-1. The second factor is the dose of N and P fertilizers to use (0, 25, 50, and 75)% of the recommended dosage. The results of this study inform you about Bioorganic fertilizers containing Azotobacter and Pseudomonas fluorescens indigenous. Azotobacter bacteria produce the availability of nutrients N, which functions as Plant Growth Promoting Rhizobacteria (PGPR), these bacteria quickly colonize the root system, regulate hormonal balance, nutrition, and encourage resistance to pathogens. Pseudomonas fluorescens bacteria acts as a provider of phosphorus and nutrients in the generative phase. Both of these microbes have a role in SRI method of rice plant metabolism to increase vegetative and generative growth of rice plants with SRI method with production reaching production of 8.80 t ha-1 in B2 (3 t ha-1) and N2P2 (50%) with the production of 9.21 t ha-1, so the use of inorganic fertilizers is more efficient. Rice soil nutrient status increased pH from slightly acidic to neutral, C-organic increased from 1.27% (low) to 9.30-10.68% (high), N total from 0.13% (low) to 0.45-0.58% (high), P- available from 13.0 ppm reaching 18.0-20.0 ppm (moderate), the Bioorganic application has not been able to increase the C: N, CEC value and base saturation. Nutrient uptake of N and P on the leaves of rice plants is better at dose B2. Bioorganic applications increase the nutrient content of paddy soils planted with the SRI method compared to initial soil nutrient analysis.

The Effect of Growth Activators and Plant Growth-Promoting Rhizobacteria (PGPR) on the Soil Properties, Root Yield, and Technological Quality of Sugar Beet

The strategy “from farm to fork” assumes a reduction in the usage of fertilizers and plant protection products in EU agriculture. The aim of this study, conducted over the years 2017–2019 in several locations in Poland, is to evaluate the application of growth activators with and without plant growth-promoting rhizobacteria to reduce mineral nitrogen fertilization without negative effects on the root yield. We studied the effect of these activators on selected soil properties. The experimental treatments included the application of the growth activators Penergetic (K + P) and Azoter, which contains the bacteria Azotobacter chroococcum, Azospirillum brasilense, and Bacillus megaterium, before sowing or during vegetation. The nitrogen rates were reduced by 30% in comparison to full nitrogen mineral fertilization (control treatment). In selected experiments, the application of Penergetic and Penergetic with Azoter caused a higher content of nitrate nitrogen (N-NO3) and ammonium nitrogen (N-NH4) after the sugar beet harvest as well as higher contents of mineral nitrogen (Nmin), P, K, and Mg in the soil in comparison to the treatment with the full dose of mineral nitrogen fertilization. The obtained results proved that it was possible to reduce the mineral application of nitrogen by 30% without a decrease in the biological and pure sugar yield, and even with an increase in the sugar yield caused by the application of the growth activators Penergetic (K + P) and Azoter.

Efficacy of integrated microorganisms in controlling root-knot nematode Meloidogyne javanica infecting peanut plants under field conditions

BackgroundPeanut (Arachis hypogaea L.) is considered one of the most important legume and oil crops in Egypt. Root-knot nematodes Meloidogyne spp. is the most damaging nematodes of peanut. Losses can exceed 50% in severely infested soil. Application of nematicides is one of the primary strategies in controlling plant-parasitic nematodes. The nematicides are proven to be hazardous to the environment. A promising alternative is the use of microorganisms antagonistic to plant-parasitic nematodes. Some microorganisms that can grow in the rhizosphere such as Azotobacter and Bacillus bacteria and fungi, e.g., Tricoderma and Paecilomyces represent the front line of defense for roots against nematode attack and ideal for use as biocontrol agents.ObjectivesThe main aim of this study was to evaluate the efficacy of application of yeast fungus Saccharomyces cerevisiae singly or combined with fusant Bas 8; (Bacillus amyloliquefaciens and Lysinibacillus sphaericus Amira strain); Bacillus thuringiensis strain code K, Trichoderma harzianum, or Paecilomyces lilacinus to control the root-knot nematode Meloidogyne javanica infecting peanut plant cv. Giza 6, and to estimate their yield under field conditions.ResultsCompared to the untreated control, all treatments exhibited variable potential inhibitory activities against root-knot nematode M. javanica and enhanced peanut yield production. The most nematode suppressive treatment was the single treatment of Saccharomyces cerevisiae, followed by T. harzianum either singly or combined with the yeast. Moreover, data indicated that application of the combined treatment of yeast plus T. harzianum gave the best results in improving peanut production, plant growth parameters, and seed nutrient contents.ConclusionIt was concluded that integrated application of microorganisms could enhance peanut production and reduce the need for either chemical fertilizers or nematicides.

RETARDED GROWTH OF LOWLAND RICE IN SALINE SOIL INOCULATED WITH NITROGEN-FIXER AZOTOBACTER

Low-land rice ( Oryza sativa L.) cultivation in saline soils face some constraints include nitrogen availability. Saline-resistant nitrogen fixing bacteria Azotobacter are expected to increase supply nitrogen in saline soils. The objectives of the study were to determine the effect of liquid inoculant concentration of two Azotobacter isolates on early vegetative growth of lowland rice grown in potted saline soil. The greenhouse trial design was a randomized block design with seven treatments and four replications. The treatments were combination of isolates and Azotobacter liquid inoculant concentrations in single and mixed inoculation. The results showed that all plants experienced chlorosis and stunt due to high Electrical Conductivity. Inoculation of different isolates and concentrations did not influence the growth of lowland rice in soil with high EC at the end of experiment. Therefore, neither isolates nor concentration of Azotobacter could improve retarded-growth of lowland rice in saline soil.

Crecimiento de Citrange troyer y atributos químicos-microbiológicos del suelo en respuesta a diferentes fertilizantes orgánicos

La producción citrícola depende principalmente en la disponibilidad de portainjertos sanos, apropiados y vigorosos; parte de su reproducción está asociada con el uso de fertilizantes químicos, que contribuyen en la contaminación de los ecosistemas. El uso de fertilizantes orgánicos son alternativas para reducir el uso de fertilizantes químicos. El objetivo de este trabajo fue evaluar el efecto de tres fertilizantes orgánicos (estiércol de gallina, cachaza (1 y 2) y pinzote) suministrados en tres dosis (1, 2 y 3%), en las propiedades químicas y microbiológicas del suelo y en el crecimiento del portainjerto Citrange troyer, en invernadero. Se utilizó un diseño completamente al azar con 14 tratamientos y seis repeticiones cada uno, incluyendo dos testigos (absoluto y fertilizado). Mediante diluciones seriadas en medios específicos se cuantificó Azospirillum, Azotobacter, y bacterias solubilizadoras de fosfatos y de potasio. Los hongos micorrízicos arbusculares fueron evaluados según la técnica de clareo y tinción con azul tripano. El pH del suelo se incrementó 0.9 unidades al agregar 1% de cachaza-2; mientras que el carbono orgánico se elevó 0.7% con el estiércol de gallina al 1%. Las bacterias Azospirillum, Azotobacter y solubilizadoras de fosfatos, se incrementaron en los tratamientos suministrados con cachaza-1 1% y estiércol de gallina 1%. La cachaza-1 2%, indujo mayor colonización micorrízica y mayor crecimiento de la planta. Ocho de los doce tratamientos con fertilizantes orgánicos utilizados, modif icaron positivamente las propiedades químicas y microbiológicas del suelo, dando como resultado un mejor crecimiento de Citrange troyer comparado con los testigos.