How do mycorrhizae work?
Mycorrhizal fungi attach to the surface of the root and penetrate in or around the inside of the root cells. Filaments (called mycelium) extend […]
View DetailsHow can root knot nematode galls and Rhizobium nodules be distinguished on the roots of legumes?
The galls of rkn are swellings within the root, which cannot be rubbed off by hand (below right) and Rhizobium nodules are external balls […]
View DetailsAre all Rhizobium the same?
Even among rhizobia that can nodulate the same plant, there are many different, geneti-cally distinct, strains. Some fix nitrogen better—more efficiently—than others, resulting in […]
View DetailsHow does having a legume in the rotation help other crops in the rotation?
The fixed N2 is released when the plants die, making it available to other plants and this helps in fertilizing the soil. If the […]
View DetailsHow much nitrogen can Rhizobium fix in a legume crop?
Legumes can fix more than 250 kg N per hectare. However, the amounts of N2 fixed can vary considerably depending on pesticide applications to […]
View DetailsHow does symbiotic relationship between legumes and Rhizobium work?
A symbiotic relationship between the plant and the microbe requires both the plant and the microbe to benefit. This requires some compromises to take […]
View DetailsDo microbes colonise all types of plant roots to the same extent?
Plants are able to shape their rhizosphere microbiome by secreting different exudates attractive to different soil microbes. Different plant species host specific microbial communities […]
View DetailsHow can PGPR affect the morphology of roots?
Some PGPRs produce phytohormones (e.g. auxin), which promote the formation of later-al roots. Increased lateral root formation leads to an enhanced ability to take […]
View DetailsWhat are the modes of action of PGPRs?
PGPR can (a) increase nitrogen availability to the plant (b) precipitate insoluble com-pounds from the soil and sequester these in their own cell components […]
View DetailsWhat are plant growth-promoting rhizobacteria (PGPR)?
Rhizobacteria are root-colonizing bacteria that form symbiotic relationships with many plants. The name comes from the Greek rhiza, meaning root. Though parasitic varieties of […]
View DetailsWhy do fungi and bacteria colonise roots?
Roots release nutrients made up of organic acids and inorganic hydrocarbons that microbes use as a food source. Soil microbes will colonise hot spots […]
View DetailsHow important is secondary pick up of EPF spores sprayed onto leaf surfaces?
Whilst there is some secondary pick of EPF spores by host insects passing by spores previously deposited on the leaf by commercial spray applications […]
View DetailsWhy do EPFs not kill predators and parasitic wasps?
The parasitic wasps have defense mechanisms, which protect them from infection by EPFs. The EPFs tend to be very specific in their target pest […]
View DetailsWhen is it advantageous for an EPF to kill the host more slowly?
If the EPF is being used in an auto-dissemination device and is relying on the host to re-distribute the EPF within the pest population […]
View DetailsHow long does it take for an EPF to kill the pest?
The speed of death depends on the application rate of the biopesticide, the temperature and the susceptibility of the pest to that particular isolate […]
View DetailsHow do entomopathogenic fungi kill pests?
The spores of an entomopathogenic fungus must land on a target pest, which it recog-nizes as a host before it will even germinate. Once […]
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