Combining endophytic fungi and bacteria for the biocontrol of Radopholus similis (Cobb) Thorne and for effects on plant growth

Eight endophytic fungal and bacterial isolates with antagonistic activity against Radopholus similis were evaluated in vivo for their individual and combined effects on biocontrol of R. similis and on the growth of “Grand Naine” cultivar banana plantlets in the greenhouse. Penetration efficiency (PE) of R. similis was between 3 and 21% in 29 biological agents (BAs) treatments, less than the 29% of the nematode-alone control (p ≤ 0.0001); 24 of the BAs treatments did not differ from the PE of 5% for a nematicide control. Twenty nine BAs treatments exhibited antagonistic activity against nematodes which reduced final population levels between 18 and 93%, relative to those on nematode-alone control plants (p ≤ 0.0001), and 14 BAs treatments were statistically similar to the nematicide treatment (88% reduction). Twenty four BAs treatments had increments of plant root biomass ranging from 20 to 58%, greater than the control plants; 37% of the treatments with single and combined BAs inoculations had root length increments ranging from 29 to 54% compared with control and chemical treatment. The nematicide, Terbufos 10GR, did not affect plant growth.     

Novel and simple approach using synthesized nickel nanoparticles to control blood-sucking parasites

The present study was on assessment of the anti-parasitic activities of nickel nanoparticles (Ni NPs) against the larvae of cattle ticks Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum (a.) anatolicum (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, Culex quinquefasciatus and Culex gelidus (Diptera: Culicidae). The metallic Ni NPs were synthesized by polyol process from Ni-hydrazine as precursor and Tween 80 as both the medium and the stabilizing reagent. The synthesized Ni NPs were characterized by Fourier transform infrared (FTIR) spectroscopy analysis which indicated the presence of Ni NPs. Synthesized Ni NPs showed the X-ray diffraction (XRD) peaks at 42.76°, 53.40°, and 76.44°, identified as 1 1 1, 2 2 0, and 2 0 0 reflections, respectively. Scanning electron microscopy (SEM) analysis of the synthesized Ni NPs clearly showed that the Ni NPs were spherical in shape with an average size of 150 nm. The Ni NPs showed maximum activity against the larvae of R. (B.) microplus, H. a. anatolicum, A. subpictus, C. quinquefasciatus and C. gelidus with LC₅₀ values of 10.17, 10.81, 4.93, 5.56 and 4.94 mg/L; r² values of 0.990, 0.993, 0.992, 0.950 and 0.988 and the efficacy of Ni-hydrazine complexes showed the LC₅₀ values of 20.35, 22.72, 8.29, 9.69 and 7.83 mg/L; r² values of 0.988, 0.986, 0.989, 0.944 and 0.978, respectively. The findings revealed that synthesized Ni NPs possess excellent larvicidal parasitic activity. To the best of our knowledge, this is the first report on larvicidal activity of blood feeding parasites using synthesized Ni NPs.     

The role of “effective microorganisms” in the composting of banana (Musa ssp.) residues

“Effective microorganisms” (EM) are a poorly defined mixture of supposedly beneficial microorganisms that are claimed to enhance microbial turnover in compost and soil. In Costa Rica, EM are used to produce organic compost (bokashi) from banana residues (Musa ssp.). Given the scarcity of scientific data about the effects of EM on the mineralization of plant residues, this study aimed at investigating the effects of EM addition on the decomposition of banana residues during Bokashi production. To this end, the following non‐EM treatments were compared to EM Bokashi: Bokashi produced with water (W), with molasses (M) as an EM additive, and with sterilized EM (EMst). Subsequently, the effects of the resulting Bokashi treatments on the growth of young banana plants were evaluated. Compared with non‐EM controls, the effect of EM on the mineralization of banana material was negligible. Dry‐matter losses of the composts with different EM treatments were similar, with about 78% over 5 weeks. Ergosterol concentration was highest in EM Bokashi (77 µg (g dry soil)^–1) and lowest in EMst Bokashi (29 µg (g dry soil)^–1). Microbial biomass carbon (C_mic) and microbial biomass nitrogen (N_mic) were both lowest in EM (C_mic = 3121 µg g^–1; N_mic = 449 µg g^–1), while C_mic was highest in Bokashi produced with molasses (3892 µg g^–1) and N_mic was highest in EMst (615 µg g^–1). Treatment effects on adenylate concentrations and adenylate energy charge were negligible. Application of all Bokashi variants to young banana plants significantly increased shoot growth under greenhouse conditions compared to plants grown in a control soil without amendments. However, these effects were similar for all Bokashi treatments, even if EM Bokashi increased the K concentrations in banana leaves significantly compared to Bokashi produced with EMst and the control. Bokashi produced with only molasses and EM Bokashi decreased the number of root nematodes under greenhouse conditions compared to the control. Overall, the results confirmed the expected influence of composting on the degradation of organic material and the effect of compost application on plant growth. Hower, under the conditions of this study, EM showed no special effects in this, except for increasing the K concentrations in the leaves of young banana plants.     

Suitability of Antimicrobial Grouper Bone Gelatin Films as Edible Coatings for Vacuum-Packaged Fish Steaks

ABSTRACT

Grouper bone gelatin films were prepared along with chitosan (GC), clove (GL), and pepper (GP) essential oils and examined for their mechanical, barrier, and antimicrobial properties. GC films had a high tensile strength (TS) of 28 MPa, and GL and GP films had a high elongation at break (EAB) of 162 and 166%, respectively. Water solubility and water vapor transmission rate (WVTR) were low in GL films. All the films exhibited inhibitory activities against Staphylococcus aureus, Aeromonas hydrophila, and Listeria monocytogenes. Vacuum-packed fish steaks coated with GC and GL film extended the shelf life from 4 days to 8 days at 4ºC.     

A Rational Approach to Scheduling Main-System Maintenance

Rational methods for setting priorities formaintenance of irrigation systems aredeveloped. The methods, which are aimed foruse by irrigation system managers, describethe link between maintenance activities andthe consequent improvement in theperformance of an irrigation system.Hydraulic analysis methods are developedfor assessing potential `restorativemaintenance' tasks, which are usuallyundertaken to increase the deliveries ofwater to the outlets. The new methods useinputs that have been limited to thoseeasily available from scheme records, theknowledge of irrigation agency staff andfrom infrastructure inspections. Twoalternative methods are developed, onebased on Fuzzy Logic and one on numericalmodelling. Risk analysis methods are alsodeveloped for assessing `preventativemaintenance', to reduce the probability ofsupply failures. Benefit-cost ratios arederived that allow direct comparisonbetween maintenance tasks of each type. Themethods are tested at two irrigationsystems in Tamil Nadu, India.     

Type II Collagen and Gelatin from Silvertip Shark (Carcharhinus albimarginatus) Cartilage: Isolation,Purification, Physicochemical and Antioxidant Properties

Type II acid soluble collagen (CIIA), pepsin soluble collagen (CIIP) and type II gelatin (GII) were isolated from silvertip shark (Carcharhinus albimarginatus) cartilage and examined for their physicochemical and antioxidant properties. GII had a higher hydroxyproline content (173 mg/g) than the collagens and cartilage. CIIA, CIIP and GII were composed of two identical α₁ and β chains and were characterized as type II. Amino acid analysis of CIIA, CIIP and GII indicated imino acid contents of 150, 156 and 153 amino acid residues per 1000 residues, respectively. Differing Fourier transform infrared (FTIR) spectra of CIIA, CIIP and GII were observed, which suggested that the isolation process affected the secondary structure and molecular order of collagen, particularly the triple-helical structure. The denaturation temperature of GII (32.5 °C) was higher than that of CIIA and CIIP. The antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl radicals and the reducing power of CIIP was greater than that of CIIA and GII. SEM microstructure of the collagens depicted a porous, fibrillary and multi-layered structure. Accordingly, the physicochemical and antioxidant properties of type II collagens (CIIA, CIIP) and GII isolated from shark cartilage were found to be suitable for biomedical applications.     

Potential distribution and damage of invasive rugose spiraling whitefly,Aleurodicus rugioperculatus and their native predatory complex of with a special focus on the biology and age specific life table parameters of neuropteran predators

Phytoparasitica - The rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) was reported in India during 2016. Biological control of RSW plays an important...     

Effects of a fungicide, an insecticide, and a biopesticide on Tolypothrix scytonemoides

Lower concentrations of Bavistin supported good growth of Tolypothrix scytonemoides with maximum protein and pigment contents. The rates of photosynthetic oxygen evolution declined in cells grown in the pesticide-amended medium but rates of respiratory oxygen consumption were enhanced in cells grown in lower concentrations of Monocrotophos and Nimbicidin. Activities of nitrogenase and glutamine synthetase were affected in all the pesticide treatments but nitrogenase activity was enhanced in the presence of Bavistin. Release of ammonia and carbohydrates was enhanced in cells grown in pesticide-amended medium except for cells grown in medium containing Bavistin where the release of carbohydrates was reduced. New polypeptides of ∼280, 152, and 25 kDa (in 250 ppm Bavistin), ∼58 and 28 kDa (in 0.3 and 0.2-0.4 ppm Monocrotophos, respectively) and ∼31, 28, and 26 kDa (in 0.5 and 1.0 ppm Nimbicidin) were detected in the treated cells.