Open Access Original Research Article

Impact of Bacillus subtilis on Tomato Plants Growth and Some Biochemical Characteristics under Combined Application with Humic Fertilizer

V. N. Pishchik, N. I. Vorobyev, Yu. V. Ostankova, A. V. Semenov, A. Totolian Areg, A. A. Popov, Y. V. Khomyakov, O. R. Udalova, D. V. Shibanov, V. E. Vertebny, V. I. Dubovitskaya, O. V. Sviridova, O. S. Walsh, S. Shafian

International Journal of Plant & Soil Science, Page 1-12
DOI: 10.9734/IJPSS/2018/41148

In this study we investigated the mechanisms of action and effect of plant growth promoting rhizobacteria (PGPR) Bacillus subtilis No.2 when utilized alone and in conjunction with a humic fertilizer (HF). Different mechanisms of action of B. subtilis No.2 and HF Stimulife on tomato plants were identified in pot experiments under controlled conditions. PGPR B. subtilis No.2 was identified by using the16s rRNA gene sequence method. We applied factor analyses to evaluate differences in the responses of plants to the individual effects of B. subtilis No.2 and HF when they were used together. Auxin-producing B. subtilis No.2 enhanced tomato yield by increased average number of fruits per plant. Humic fertilizer Stimulife, which also contains auxins, improved tomato yield by increasing average fruit weight. As shown by factor analysis, the impact of weight coefficients for plant responses (across tomato varieties) to B. subtilis No.2 and Stimulife were 0.54 and 0.28, respectively, indicating a greater response to B. subtilis No.2 than to HF Stimulife. Combined use of Stimulife and B. subtilis No.2 had a positive impact on tomato yield, increasing fruit yield by 25-29%. Tomato fruit quality was improved by increasing the amounts of dry matter, carbohydrates, sugar-index acid, and ascorbic acid. Results suggest that HF Stimulife and B. subtilis No.2could be successfully used to enhance tomato plant growth and yield under controlled conditions. We hypothesize that, along with direct impact, HF may also indirectly affect plants by stimulating PGPR.

Open Access Original Research Article

Prevalence of Fluorescent Pseudomonads in Cruciferous Rhizosphere, Their Characterization and Severity of Black Rot of Cabbage in Northern Karnataka

Beeresh Lamani, Shripad Kulkarni

International Journal of Plant & Soil Science, Page 1-8
DOI: 10.9734/IJPSS/2018/41020

Cabbage (Brassica oleraceae var.capitata (L.)) is one of the most important vegetable crop and cultivated extensively in tropical and temperate regions of the world. Cabbage infected by many diseases among those, black rot of cabbage caused by Xanthomonacampesrtis pv. campestris is one of the most yield limiting and destructive pathogens of cruciferous crops worldwide. A random survey conducted during Kharif 2015 in cabbage growing areas of northern Karnataka revealed that incidence of black rot of cabbage was observed in all district surveyed. The maximum disease index of 23.36% was noticed in Belagavi district, followed by Dharwad (20.17%) and the least disease index was observed in Haveri (18.65%). The severity of black rot was highest at heading stage compared to vegetative stage. Prevalence of fluorescent pseudomonads was observed in all districts surveyed and wherever fluorescent pseudomonads were present in those locations the disease occurrence and severity was less compared to location where pseudomonads were they were absent. Eight fluorescent pseudomonads such as GRG- FP, HGK- FP, LKR- FP, KKL- FP, KBG- FP, KBG- FP, SKP- FP, MKH- FP and ARB- FP were identified based on their morphological characters, physiological and biochemical tests.

Open Access Original Research Article

Effects of Three Pesticides (Atrazine, Deltamethrin and Acetamiprid + Cypermethrin), Two Plant Species (Vetiveria nigritana Benth. and Oxythenantera abyssinica Linn.) and Their Interactions on the Biological Activity of Lixisols and Vertisols of Cotton Agrosystems of Burkina Faso (West Africa)

Issaka Senou, Jean Ouédraogo, Antoine N. Somé, Hassan B. Nacro

International Journal of Plant & Soil Science, Page 1-11
DOI: 10.9734/IJPSS/2018/41340

Aims: The application of pesticides can have adverse effects on the biology of agricultural soils. This study had 3 objectives: (i) evaluate the impact of the three pesticides on soils, (ii) evaluate the impact of the two plant species on soils and (iii) also evaluate the interaction of pesticides and plant species on soils.

Methodology: In order to achieve this aim, an experimental test was conducted in a vegetal vase with 7 treatments. The experimental device used is a split-plot device with four repetitions for each soil type. The main treatments are plant species and secondary treatments consist of pesticides. The main factor had three modalities namely: absence of plant, Oxytenanthera abyssinica and Vetiveria nigritana. As for the secondary factor, it comprises four modalities which are: control, Atrazine, Deltamethrin and Acetamiprid + Cypermethrin. Deltamethrin and acetamiprid + cypermethrin are not a mixture. They constitute 2 different pesticides. It is rather acetamiprid + cypermethrin which is a mixture of acetamiprid and cypermethrin.

Results: Physicochemical characteristics are generally lower in lixisols compared to vertisols, except P and K. Microbial biomass is lower in the presence of plant species regardless of soil type. Microbial biomass has declined regardless of the type of pesticide. This decrease was significant (P = 0.045) in lixisols. Pesticide interaction and plant species significantly increased (P = 0.01) microbial biomass in the presence of Vetiveria nigritana and respiratory activeness for both species. The highest cumulative release values ​​are found in soils without plants. Analysis of variance revealed highly significant differences (P <0.001) in lixisols. The application of Atrazine and Cypermethrin + Acetamiprid increased respiratory activity regardless of soil type. Cumulative values ​​are higher in lixisols than in vertisols.

Conclusion: The pesticides used induce a decrease in the microbial biomass of the soil and promote a stimulation of the respiratory activity. The plant species tested induce a decrease in microbial biomass as well as the mineralization that expresses the release of CO2 in lixisols and vertisols. The interaction between plant species and pesticides increases microbial biomass and respiratory activity in both soil types

Open Access Original Research Article

The Evaluation of Water Regulation Agroecosystem Services in Context with Risk Area Determination

Makovníková Jarmila, Houšková Beáta, Širáň Miloš, Pálka Boris, Kanianska Radoslava, Kizeková Miriam

International Journal of Plant & Soil Science, Page 1-9
DOI: 10.9734/IJPSS/2018/41098

Aim of this study is to assess and map the retention capacity of the soil in agroecosystem, the capacity of the ecosystem to provide water regulation in Slovak Republic, as well as to describe the use of GIS techniques in creating an uniform spatial units for agroecosystem services inventor. We have created a mapping unit combining these input layers: slope topography, soil texture and usage of land in four climatic regions. Potential of water regime regulation (soil water storage) is determined on the basis of the value of retention water capacity recalculated to soil water storage in context with the soil depth. Evaluated potential of water regulation service was categorised into five categories (very low, low, medium, high and very high). In Slovakia 27.47% of the area of agricultural ecosystems has very high potential for regulation of water regime (accumulation of water in the soil). They are mostly ecosystems of arable land located in Eastern Slovak Lowland, Danubian Upland, South-Slovak Basin and Košice Basin with heavy clay loam and clayey deep soils without skeleton. Ecosystems with very low and low potential for water storage occupy 32.04% and these are predominantly grasslands. To identify the risk areas, we evaluated the potential of water regulation in relation to factor R, which represents the risk of torrential rain. In Slovakia 18.20% of the area of agricultural ecosystems has from very high to high risk of agroecosystem degradation. The methodology developed in this paper is replicable and could be applied by planners in the case they are proficient in geographical information systems.

Open Access Original Research Article

Yield Response of Cicer arientium L. as Influenced by Plant Growth Promoting Rhizobacteria in Rainfed Loess Soils

Muhammad Rashid, Obaid ur Rehman, Shahzada Munawar Mehdi, Sarosh Alvi, Aftab Ahmad Sheikh, Hassan Mehmood, M. Imran Akram, Raja Abad Raza

International Journal of Plant & Soil Science, Page 1-10
DOI: 10.9734/IJPSS/2018/41070

Climate change has greatly affected rainfall distribution and intensity in the rainfed areas of the world which has created water shortage and soil moisture deficiency and causing crop yield reduction. Soil microorganisms have great potential to improve soil fertility and enhance plant nutrition by minimizing the damages of water stress since water stress inhibits plant growth due to higher concentrations of ethylene in rhizosphere. Rhizobacteria containing ACC-deaminase, assist plant growth to tolerate these injurious effects. To test this hypothesis under rainfed sloppy lands an experiment was conducted consisting of treatments including gypsum,  plant growth promoting rhizobacteria (PGPR), farmyard manure (FYM) and, PGPR+FYM in randomized complete block design (RCBD) arrangement to assess their effectiveness for improving growth of chickpea and changes in soil characteristics. The results of this experiment revealed that selected amendments increased grain and straw yield significantly (p ≤ 0.05). The mean maximum grain yield (1519 Kg ha-1) and biomass yield (1862 Kg ha-1) was recorded where PGPR was applied in combination with FYM. It was observed that grain yield was enhanced 6, 11, 13 and 19 % and biomass yield was increased 12, 15, 17 and 23% by gypsum, PGPR, FYM and PGPR+FYM, respectively over control (zero addition). Application of amendments enhanced soil organic matter and saturation percentage up to 27 and 5%, respectively while soil pH and EC were reduced by 2 and 18%, respectively. So, it was concluded that soil amendments especially PGPR can be used effectively to combat the soil moisture shortage under stress conditions to enhance the soil and crop productivity in rainfed conditions under changing climate scenario.