Botrytis causes a brown/grey powdery coating on plant tissue. Many crops are susceptible to this fungal infection, both outdoors and under glass. Above-ground dead organic material is first affected, after which the fungus spreads to living, healthy plant tissue.
This grey (necrotrophic) fungus is not directly inhibited through the plant’s natural immune system via the salicylic acid signal pathway because defence against this fungus takes place via the jasmonic acid signal pathway. The application of salicylic acid in the case of botrytis, therefore, will generally not work. What does help is to apply Cuprum as this specifically stimulates the production of defence proteins via the jasmonic acid signal pathway.
We have particularly positive experiences with salicylic acid in tomato production, where it is used to dry out the wounds produced when the leaves break off that make the fruit more susceptible to botrytis. A callus (wound tissue) even develops along the edges of the wound so that the fungus has less chance of infecting the plant.
The application of SilicaPower also has a positive effect: the cell walls and the leaf surface are strengthened so that the fungus has less opportunity to infect the plant.
Finally, the elevated pH achieved with the application of Ds-Lime also affects fungi such as botrytis, which survives less well at a pH of 12.
For most crops (see separate information for tomatoes), we recommend spraying Cuprum or applying it via LVM. Cuprum stimulates the production of proteins in the jasmonic acid signal pathway.
For tomato production, we recommend administering SalicylPure in the B fertilizer feeder.
Are you an organic tomato grower? If so, administering SalicylPure is not an option as you grow in the field. In this case, we recommend spraying Algicin®: this contains the same amount of salicylic acid as SalicylPure and is suitable for use in organic farming.