Benefits of inoculation with azotobacter in the growth and production of tomato and peppers

The aim of this research was to investigate the effects of Azotobacter chroococcum in tomato and pepper growth and production by using two types of inoculation - seed inoculation and seedling inoculation. The effect of inoculation was observed thirty days after sowing, thirty days after transplanting, and in the phase of technological maturity. The following were measured: height of the plants, dry matter of the plants and number and the weight of the fruits. Inoculation had a positive effect on these in both plants. With tomato, better results were achieved when seedlings were inoculated. With pepper, the length of the plant and the dry matter were greater with seedling inoculation, whereas the number and the weight of the fruits were greater with seed inoculation

Stimulating effect of microalgae on germination and initial growth of red radish (Raphanus sativus L. var. Radicula Pers.)

Microalgal application in plant producton are becoming promising alternative practice aiming to enhance seed germination performance. Red radish is one of the most commonly eaten vegetables in early spring in Serbia. The effect of two microalgae on red radish germination and growth promotion was tested. Two concentrations (1 and 2%) of Chlorella sp. (strains 71 and 72) suspension were prepared. The root and shoot length, weight of fresh biomass and germination percentage were assessed. The highest germination, root and shoot length were determined after Chlorella sp. strain 71 treatment with 2% concentrated suspension. Lower concentration of the same microalga led to the highest fresh shoot biomass. Red radish root (+106 %) and shoot length (+27%) were increased by 1 % and 2% Chlorella sp. (72) water suspension, respectively

Mikrobiološke transformacije jedinjenja fosfora i sumpora u kiselim zemljištima

The dynamics of phosphorus and sulphur in soil is closely related to the dynamics of the biological cycle in which microorganisms play a central role. There is not much microbiological activity in acid soils because aerobes are scarce, rhizosphere is restricted to the shallow surface layer, and the biomass of microorganisms decreases with higher acidity. The aim of the research was to investigate the number of microorganisms, which decompose organic and inorganic phosphorus compounds and organic sulphur compounds in calcocambisol, luvisol, and pseudogley. The following parameters were determined in the soil samples: pH in H2O and in 1MKCl; the content of CaCO3 (%); humus content (%), nitrogen content (%); the content of physiologically active phosphorus and potassium (mg P2O5/100g of soil; mg K2O/100g of soil). The number of microorganisms was determined by the method of agar plates on appropriate nutrient media: the number of microorganisms solubilizing phosphates on a medium by Muramcov; the number of microorganisms that decompose organic phosphorus compounds on a medium with lecithin; and the number of microorganisms that transform organic sulphur compounds on a medium by Baar. All three types of soil are acid non-carbonate soils with a low level of available phosphorus and a more favorable amount of potassium, nitrogen, and humus. The largest number of bacteria, which transform organic phosphorus compounds, was found in calcocambisol. The largest number of phosphate solubilizing bacteria was recorded in pseudogley, whereas the largest number of phosphate solubilizing fungi was recorded in calcocambisol. The largest number of bacteria, which transform organic sulphur compounds, was recorded in pseudogley.Dinamika fosfora i sumpora u zemljištu tesno je povezana sa dinamikom biološkog ciklusa u kojem mikroorganizmi imaju centralnu ulogu. Mikrobiološka aktivnost u kiselim zemljištima nije velika, jer su potisnuti aerobi, rizosfera je ograničena na plitku površinsku zonu, a sa povećanjem kiselosti smanjuje se i biomasa mikroorganizama. Cilj ovih istraživanja je bio da se ispita zastupljenost mikroorganizama koji razlažu organska i neorganska jedinjenja fosfora i organska jedinjenja sumpora u kalkokambisolu, luvisolu i pseudogleju. U uzorcima zemljišta određeni su sledeći parametri: reakcija zemljišta (pH) u H2O i u 1MKCl; sadržaj CaCO3 (%); sadržaj humusa (%); sadržaj azota (%); sadržaj fiziološki aktivnog fosfora i kalijuma (mg P2O5/100g zemljišta; mg K2O/100g zemljišta). Broj mikroorganizama određivan je metodom agarnih ploča na odgovarajućim selektivnim hranjivim podlogama: broj mikroorganizama koji razlažu fosfate na podlozi po: Muramcov, broj mikroorganizama koji razlažu organska fosforna jedinjenja na podlozi sa lecitinom, a broj mikroorganizama koji transformišu organska jedinjenja sumpora na podlozi po Baar-u. Sva tri tipa zemljišta spadaju u grupu kiselih beskarbonatnih zemljišta, sa niskim sadržajem pristupačnog fosfora i povoljnijim sadržajem kalijuma, azota i humusa. Najveći broj bakterija koje transformišu organska jedinjenja fosfora utvrđen je u kalkokambisolu. Najveći broj bakterija koje razlažu fosfate utvrđen je u pseudogleju, a najveći broj gljiva koje razlažu fosfate u kalkokambisolu. Najveći broj bakterija koje transformišu organska jedinjenja sumpora utvrđen je u pseudogleju

Isoflavone content and antioxidant activity of soybean inoculated with plant-growth promoting rhizobacteria

Plant-growth promoting rhizobacteria (PGPR) elicit activation of the phenylpropanoid pathway in plants, which leads to phenolics production and enhanced antioxidant capacity. The purpose of this work was to assess the antioxidant activity of soybean plants, Glycine max L., inoculated with PGPR (isolates of Azotobacter chroococcum, Streptomyces sp. and mixture of these) during plant development, as well as the yield of inoculated soybean plants. PGPR applied in the experiment stimulated flavonoids and isoflavone synthesis, which enhanced the non-enzymatic antioxidant ability of the soybean plants. Moreover, PGPRs stimulated the accumulation of daidzein and genistin in soybean seedlings (5-fold and 2-fold compared to the control values, respectively). The mixture of PGPRs had a positive impact on the antioxidant activity (10-20 % higher activity) and yield components of soybean, which proposed this inoculum as possibly a potent bio-fertilizer in soybean production

Flame-weeding: Impact on soybean plants and soil microorganisms

Flame-weeding is a very useful method for weed control, especially in organic production where the use of herbicides is prohibited. With this method heat sup­presses weeds in row within a second. Apart from this, heat also affects growing crop plants and surrounding soil. The aim of this paper was to determine the effect of different propane doses, on photosynthetic and polyphenolic (total flavonoids and anthocyаnins) pigments in soybean leaves, as well as the number of microorganisms in the soil. Soybean plants exposed to flame showed a different reaction to high temperature stress, which was reflected in differ­ent content of analyzed biochemical parameters, but the most responsive were anthocyanins. Actinomycetes turned out to be the most sensitive group of soil microorganisms affected by weed flaming, while fungi were the most tolerant

Effect of inoculation with PGPR on basil antioxidant activity

Basil (Ocimum basilicum L.) is a widely utilized culinary herb. It is used to flavour foods such as vegetables, meats, fish, etc. In traditional medicine is used for treatment of various disorders such as colds, respiratory diseases, cardiovascular diseases, metabolic and gastrointestinal disorders, etc. The effects of climate changes on agriculture can result in lower yield and nutritional quality of plants. The inoculation of plants with plant growth-promoting rhizobacteria (PGPR) such as Azotobacter, Streptomyces, and Bacillus are well known to lead to improvement in germination, growth, and yield. Also, it was found that PGPR enhance defence capacity of the plant. In this study, the basil seed were inoculated with selected PGPR isolates: Bac3, Azb, and Act. Control seeds were immersed into distilled water. After 6 weeks plant material was collected, and methanol extracts were prepared for antioxidant determinations. The changes in total phenol and flavonoid content, as well as antioxidant activity, were monitored. PGPR applied in the experiment have not cause significant changes in total phenol content. However, treatments with Azb and Act isolates have increased flavonoid content in basil plants. The antioxidant activity of basil plant has been measured as the ability of plant extracts to reduce DPPH radicals. Obtained results show that only treatment with Azb isolates significantly increases the antioxidant activity of basil plants. Results obtained in this study suggested that investigated isolates have different effects on the antioxidant characteristics of the basil plant. Further investigation is still needed to explore the possibility of using these PGPRs as potent bio-fertilizer in basil production

Impact of flaming on soybean plants and soil microorganisms

The use of open flame (flaming) is a very useful method for weed control, especially in organic production where the use of herbicides is prohibited. There, the heat suppresses weeds in row within a second. But apart from this, heat also affects growing plants and surrounding soil including microorganisms. The aim of this study was to determine the effect of different propane doses (20, 30, 40, 50, 60, 70, 80 and 100 kg/ha propane) on photosynthetic (chlorophylls and carotenoids) and polyphenolic (total flavonoids and anthocyаnins) pigments in soybean leaves, as well as the number of microorganisms in the soil. Flame-weeding machine was modified four row cultivator with two burners placed on both side of each row to suppress weeds in the row of the crop. Young soybean plants were treated with flame in three growth stages: the first trifoliate or V1, the three trifoliate or V3 and the six trifoliate stage or V6. Plants were sampled together with their roots, five hours after treatment. Soil samples for microbiological analysis were taken between the rows of soybean 1h and 24h after flaming, at the depth of 2 cm

Mikrobiološka aktivnost u zemljištu pod pšenicom

The investigation included examining the effect of soil compaction, soil depth and vegetation period on the number of microorganisms in soil covered with wheat. The soil samples were taken twice during the vegetation period (March, June 2007) from the depths of 0-30cm and 30-50cm, both from the central (loosing) and compacted parts of the lot. With all groups of microorganisms, apart from fungi and oligonitrophyls, the greatest number was observed in the central part of the lot. All groups of microorganisms were more abundant in ploughing layer of soil (0-30cm). The total number of microorganisms, ammonifiers, actinomycetes and oligonitrophyls was greater at the beginning of the vegetation period, whereas the total number of fungi and azotobacter was greater at the end of the vegetation period.U radu je ispitivan uticaj sabijenosti zemljišta, dubine i perioda vegetacije na brojnost mikroorganizama u zemljištu pod pšenicom. Zemljište je uzorkovano sa dubine 0-30 i 30-50 cm, sa centralnog (rastresitog) i sabijenog dela parcele (uvratine), dva puta tokom vegetacije pšenice (mart i jun 2007). Kod svih grupa mikroorganizama, osim kod gljiva i oligonitrofila, brojnost je bila veća u centralnom delu parcele.Sve grupe ispitivanih mikroorganizama su bile brojnije u oraničnom sloju zemljišta (0-30 cm). Ukupan broj mikroorganizama, amonifikatora, aktinomiceta i oligonitrofila bio je veći na početku vegetacije, a gljiva i azotobaktera na kraju vegetacije

Selective isolation and characterization of agriculturally beneficial bacteria from rhizospheric soil of Cannabis sativa L., Vojvodina, Serbia

Biljke, uključujući i konoplju (Cannabis sativa L), su domaćini različitih korisnih mikrobnih zajednica. Ovi mikroorganizmi se mogu naći u rizosfernom zemljištu, na biljci ili unutar biljnih tkiva, i svi zajedno čine biljnu mikrobnu zajednicu. Mikroorganizmi označeni kao biljna mikrobna zajednica se sistematski proučavaju dugi niz godina, i velika većina naučne literature se slaže oko njihove centralne uloge u podržavanju rasta, razvoja i opšteg zdravlja biljke. Cilj ovog istraživanja bio je da se iz rizosfernog zemljišta konoplje (Cannabis sativa L) izoluju bakterije roda Pseudomonas, Bacillus i Azotobacter i ispita njihov biostimulatorni (PGP od plant growth-promoting) i biokontrolni potencijal. Ova studija je potvrdila da autohtone rizosferne bakterije konoplje imaju različite sposobnosti tolerancije na abiotičke faktore i više različitih svojstava kojima mogu podstaći rast biljaka. Izolati roda Pseudomonas su pokazali sposobnost da žive na niskim (10ºC) i visokim (37 ºC) temperaturama. Svi izolati su imali minimalan rast na pH 9. Dva izolata označena kao P37 i P39 su tolerisala visoke koncentracije NaCl. Izolati su imali sposobnost da koriste različite izvore ugljenika. Svi Pseudomonas izolati produkovali su lipazu, ureazu, siderofor, cijanovodonik i razlagali jedinjenja organskog i neorganskog fosfora.Plants, including hemp (Cannabis sativa L), host different beneficial microbial communities. These microorganisms can be found in rhizospheric soil, on and inside plants tissues, designated as the plant microbiota or plant-associated microorganisms. The plant-associated microorganisms have been studied systematically for many years, and the vast majority of the scientific literature agrees upon their central role in supporting plant growth, development and overall health. The aim of this study was to isolate bacteria of Pseudomonas, Bacillus, and Azotobacter from the rhizospheric soil of hemp (Cannabis sativa L.) and investigate their biostimulatory (plant growth-promoting – PGP) and biocontrol potential. This study confirmed that indigenous rhizospheric bacteria of hemp have different abiotic stress tolerance abilities and multiple plant growth-promoting (PGP) properties. Pseudomonas isolates showed the ability to live at low (10ºC) and high (37 ºC) temperatures. All isolates had minimal growth on pH 9. Two isolates denoted as P37 and P39 tolerated high concentrations of NaCl. Isolates had the ability to use different sources of carbon. All Pseudomonas isolates produced lipase, urease, siderophore, hydrogen cyanide, and utilized organic and inorganic phosphorus

Azotobacter, Pseudomonas and Bacillus isolates stimulate the germination and seedling growth of Mellisa officinalis

The objective of this study was the isolation and characterization of Azotobacter, Pseudomonas and Bacillus species from the rhizospheric soil of Mellisa officinalis and to examine the effect of isolates application on the seed germination and seedling growth. Isolation, physiological, biochemical, and plant-growth-promoting activity characterization of isolates were done. Monitoring the effects of isolates application on seed germination and seedling growth were evaluated in controlled conditions. The number of germinated seeds, the shoot and root length of seedlings, vigour index and biochemical stress markers (lipid peroxidation intensity and total phenols) were measured. From the rhizosphere of plant 2 Azotobacter (denoted as A5 and A6), 5 Pseudomonas (denoted as P27, P28, P29, P55 and P56) and 6 Bacillus (denoted as B64, B65, B66, B67, B68 and B69) bacteria were isolated. Azotobacter isolates showed the ability to live in the condition of low (5) and high (9) pH. The isolates varied in terms of the utilization of carbon sources. Both isolates produced pectinase, hydrogen cyanide (HCN) and utilized organic and inorganic phosphorus. Pseudomonas isolates had optimal growth at 10 ºC and 37 ºC, and on medium with pH 5 and 9. All Pseudomonas isolates could produce pectinase, lipase, amylose, IAA, siderophores and HCN. All Bacillus isolates could grow on a medium containing 7% NaCl