As biofungicides gain increasing recognition for their role in tackling costly fungal disease issues, experts advise that a key to success is understanding what to look for in a treatment to maximise results and protect against the widest range of damaging plant pathogens.
Lallemand Plant Care’s Andrew Gough explains that it’s vital to exploit the beneficial fungus’ ability to out-compete disease threats and protect fruit crops when they are most vulnerable.
“That’s why it’s crucial to seek products offering the right beneficial fungal strain, isolated for specific plant disease controlling properties.
“This will determine how aggressively the roots, foliage, flowers and fruit are colonised to inhibit pathogen penetration. The number of viable beneficial microbes is critical to success, and is reflected in the Colony Forming Units (CFU) per gram within the product,” explains Andrew.
“You need to be looking at achieving a beneficial micro-organism population in situ that is ideally significantly greater than the concentration of the pathogen threatening your crop.”
So, for example, the biofungicide Prestop contains a very high concentration of Gliocladium catenulatum J1446, at a minimum of 200 million CFU per gram of product, making it overwhelmingly greater than the concentration of Botrytis cinerea on a highly invaded crop when applied at the correct
rate.
“This biofungicide is highly aggressive, surviving around roots and on aerial plant parts for several weeks attacking and suppressing pathogens.”
Furthermore mycelium filaments, or hyphae, of strain J1446 are hyperparasitic secreting enzymes that dissolve cell walls of pathogenic fungi.
Prestop treatments to soil, growing media and substrates provide protection against damping-off and root/base rots caused by Phytophthora, Pythium, Rhizoctonia and Fusarium. Aerial treatments protect against Grey Mould and Cankers caused by Botrytis spp.
To optimise performance, it is important to prepare and apply the biofungicide in the right way and in the right conditions. “If soil wetness and soil plus air temperatures are conducive to disease development, then they are equally suited to assisting control with a treatment such as Prestop.
Backing this point, Lallemand trials have shown that strain J1446, contained in Prestop, is active over a wide temperature range; it thrives in air and soil temperatures of 15-25°C. Aerial growth of Botrytis cinerea (grey mould) is optimised at 18-22°C, while soil pathogens causing damping off and root rot prefer 15-20°C pre-emergence and 22-27°C post-emergence.