There has been many recent studies on the use of microbial antagonists to control diseases incited by soilborne and airborne plant pathogenic bacteria and fungi, in an attempt to replace existing methods of chemical control and avoid extensive use of fungicides, which often lead to resistance in plant pathogens. In agriculture, plant growth-promoting and biocontrol microorganisms have emerged a...

Biological control of soilborne plant pathogens using beneficial fungi, such as the mycoparasite Trichoderma harzianum, offers the prospect of environmentally benign pest control. However, biocontrol organisms have their own natural enemies; for example the fungivorous nematode Aphelenchoides saprophilus preys on T. harzianum. A trophic cascade occurs when three or more trophic levels are prese...

To study the effect of plant species on the abundance and diversity of bacterial antagonists, the abundance, the phenotypic diversity, and the genotypic diversity of rhizobacteria isolated from potato, oilseed rape, and strawberry and from bulk soil which showed antagonistic activity towards the soilborne pathogen Verticillium dahliae Kleb. were analyzed. Rhizosphere and soil samples were taken...

Pseudomonas chlororaphis PCL1391 produces the secondary metabolite phenazine-1-carboxamide (PCN), which is an antifungal metabolite required for biocontrol activity of the strain. Identification of conditions involved in PCN production showed that some carbon sources and all amino acids tested promote PCN levels. Decreasing the pH from 7 to 6 or decreasing the growth temperature from 21 to 16 d...

The soil nourishing the crops that provide our food and fiber is a complex environment where microbes live in numbers estimated to reach 2 billion per ounce of soil. Millions upon millions of individual bacteria and fungi Uve on root surfaces and the soil particles that surround them. Bacteria are the smallest and the most abundant. The fungi, usually larger than bacteria, are found throughout ...

ABSTRACT Eight different 3-year cropping systems, consisting of soybean-canola, soybean-barley, sweet corn-canola, sweet corn-soybean, green bean-sweet corn, canola-sweet corn, barley-clover, and continuous potato (non-rotation control) followed by potato as the third crop in all systems, were established in replicated field plots with two rotation entry points in Presque Isle, ME, in 1998. Cro...

Rhizoctonia stem canker and black scurf. Rhizoctonia diseases of potato are caused.Black scurf on a potato tuber caused by Rhizoctonia solani. Rhizoctonia potato disease is an important constraint to potato production. The disease.ISBN 978-952-10-5475-4 PDF http:ethesis.helsinki.fi. 2 Variation of biological traits in Rhizoctonia solani isolated from potato. Abstract Rhizoctonia solani is an im...

Changing climate is expected to alter precipitation patterns in the Arctic, with consequences for subsurface temperature and moisture conditions, community structure, and nutrient mobilization through microbial belowground processes. Here, we address the effect of increased snow depth on the variation in species richness and community structure of ectomycorrhizal (ECM) and saprotrophic fungi. S...

Elucidating symbiotic relationships between arbuscular mycorrhizal fungi (AMF) and plants contributes to a better understanding of their reciprocally dependent coexistence and community assembly. However, the main drivers of plant and AMF community assembly remain unclear. In this study, we examined AMF communities from 166 root samples of 17 woody plant species from 10 quadrats in a Chinese su...

The presence of Escherichia coli in water is used as an indicator of fecal contamination, but recent reports indicate that soil populations can also be detected in tropical, subtropical, and some temperate environments. In this study, we report that viable E. coli populations were repeatedly isolated from northern temperate soils in three Lake Superior watersheds from October 2003 to October 20...