parasitic pathogens
Damping off is a disease that afflicts young seedlings, and is common
under wet, humid conditions.
Plant Defence Systems
Plants are not without their own defence strategies when it
comes to preventing disease infection. In fact, the majority
of fungal spores and bacterial pathogens present in a growing environment never actually cause a significant disease
outbreak. A complex series of anti-microbial compounds
termed phytoalexins are produced within the plant when it
senses it’s under attack by pathogens. Phytoalexins are compounds that accumulate around the area of the invasion and
create a number of different strategies to fight, wall off and
generally limit microbial growth to prevent the disease from
The first signs of a disease outbreak can be easy to miss if regular plant
inspections are not carried out.
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Maximum Yield USA | April 2015
“
While fungal diseases are
far more common in indoor
gardens, bacterial pathogens
can still cause problems and
are more difficult to identify.”
spreading further. While phytoalexins are naturally produced by plants, there are a number of compounds known
to be inducers, which when applied to a crop can have the
ability to boost phytoalexin levels.
Some of the more commonly known phytoalexin inducers
used in crop production include salicylic acid, chitin and chitosan, phosphorous acid and phosphonate fungicides. These
stimulate the plant’s defence systems and have been incorporated into a range of commercially available plant-protection
products, but the effectiveness of the process of phytoalexin
stimulation can be somewhat variable between different
plant species and dependant on the pathogen and environment. S [