Search results for "Biological control"

Inhibition of Mycotoxigenic Fungi in Different Vegetable Matrices by Extracts of Trichoderma Species

2021

Post-harvest fungal diseases of plant products are a serious concern leading to economic losses and health risks. Moreover, the use of synthetic chemical fungicides to prevent these diseases is limited due to toxic residues. This study aimed at determining the effective dose of extracts of Trichoderma&nbsp

Physiological engineering of Pseudomonas aurantiaca antimicrobial activity: effects of sodium chloride treatment

2012

The influence of sodium chloride (NaCl) treatment on the antifungal activity of the bacterium Pseudomonas aurantiaca, a producer of biopesticide for vegetable plants, was investigated. It was shown that an increase in the NaCl concentration in incubation solutions from 1 M to 3 M led to a significant increase in the antifungal activity of this bacterium. Antifungal activity continued to increase with prolonged treatment of bacteria in fresh nutrient medium from 72 h to 96 h. These findings could be very important for the further development of biotechnological processes directed not only to the production of new active biopesticides but also of other valuable resources.

Wild olive seed weevil in South Africa, Anchonocranus oleae Marshall (Coleoptera Curculionidae), a rediscovery after a century

2019

The wild olive seed weevil, Anchonocranus oleae Marshall, 1912 was not found after its description and the study of its biology by Silvestri in 1915. Recently, A. oleae larvae were found alive inside the kernels of wild olives (O. europaea subsp. cuspidata) collected from trees between 2009 and 2012 in the Western Cape, South Africa. No weevil larvae were found in cultivated olives collected during the same period. Only two adult weevils emerged from olives collected on the tree and on the ground. Over the sampling period 20 adults were collected directly on wild olive trees at different sites in the Western Cape and one in the Eastern Cape. All adults were shown to be conspecific with the …

Fusarium wilt of cyclamen : early detection and biocontrol

2016

Fusarium wilt of cyclamen is one of the most damaging diseases of cyclamen. The causal agent, Fusarium oxysporum f. sp. cyclaminis, is a soil-borne fungus. Losses can reach more than 50 % of the production. Several methods of control are available, but none of them offer an efficient and environmentally friendly solution. In this context, a project was developed in collaboration with the French institute of horticulture, Astredhor, which represents the producers, the INRA of Dijon, for its expertise on F. oxysporum and the company Agrene for its expertise in biological control. The project has two goals: i) design a molecular marker specific of Fusarium oxysporum f. sp. cyclaminis allowing …

Build up of patches caused by Rhizoctonia solani

2010

Rhizoctonia solani is a complex species that is composed of different anastomosis groups (AG). Although these different AGs show differences in their host ranges, generally R. solani is a phytopathogenic species with a wide spectrum of hosts. It has the ability to grow as a saprotroph, which further complicates its behaviour as a parasite. The losses caused by R. solani are very important and need a sustainable management strategy. The patchy appearance of the disease caused by this pathogen is well-known. The patches show within and between season dynamics. The factors which affect the spread of the disease can be grouped into three main categories: host plant, pathogen and environment. Ho…

Preliminary study on the biology, natural enemies and chemical control of the invasive Macrohomotoma gladiata (Kuwayama) on urban Ficus microcarpa L.…

2015

[EN] The phenology and natural enemies of Macrohomotoma gladiata (Kuwayama) (Hemiptera. Homotomidae) on Ficus microcarpa L. in Valencia (Spain) were studied in 2013. During the study, all immature instars of the pest were found on infested shoots indicating overlapping generations. However, two consistent increases in the proportion of the first two nymphal instars were detected in early March and June, possibly suggesting the beginning of spring and summer generations. Eggs of Macrohomotoma gladiata were usually found below the stipules of new healthy shoots, arranged in groups of 15-30 units. First two nymphal instars usually preferred the innermost part of the shoot, whereas the older de…

Characterization of trophic links in an agrosystem : weed seed predation by carabid beetles

2012

Agroecology gives evidence of new perspectives in agriculture, and open doors for alternative weed management approaches through different regulation mechanisms. Seed predation is one of them, and the interest is growing to deepen knowledge, relative to this process. This Phd work aims (i) to describe weed seed predation, the dominant carabid predators and the available resource at a local scale in a common crop (winter wheat); (ii) to study predation profiles of main predators, and the pair-wise correlations between the biological components of the system; (iii) to bring new insights regarding potential regulation of weed communities, through seed predation by carabid beetles. Complementar…

Potential effects of Bacillus thuringiensis against adults and older larvae of Rhynchophorus ferrugineus.

2009

Biologiczna kontrola Rhizoctonia solani AG 2-2IIIB przez metabolity Bacillus subtilis

2016

Celem doświadczenia było określenie aktywności metabolitów produkowanych przez bakteryjny szczep Bacillus subtilis wobec izolatu Rhizoctonia solani należącego do grupy AG 2-2IIIB. Antagonistyczne właściwości metabolitów B. subtilis były oceniane w kulturach płytkowych na podłożu Czapka po 6, 24 i 48 godzinach hodowli w temperaturze 30 i 37ºC. Wpływ metabolitów wytwarzanych przez B. subtilis na wzrost R. solani AG 2-2IIIB przedstawiono w postaci współczynnika tempa wzrostu liniowego grzyba. Uzyskane wyniki wykazały, że na fungistatyczną aktywność metabolitów B. subtilis wobec R. solani AG 2-2IIIB wpływa zarówno czas, jak i temperatura inkubacji bakterii. Wzrost grzybni był najmocniej hamowan…

Antimicrobial activity of the red palm weevil Rhynchophorus ferrugineus

2011

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera Dryophthoridae), is an important pest of palms. Knowl- edge of both its natural enemies and its defensive mechanisms against predators and microorganisms is important to develop methods for an integrated pest control. Antimicrobial activity of the cuticular surface of adults and larvae, as well as of eggs, of this invasive species was investigated. This activity was tested against the Gram-positive bacteria Bacillus subtilis (Ehrenberg) Cohn and Bacillus thuringiensis Berliner, the Gram-negative bacterium Escherichia coli Escherich, and the entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium aniso…