AHDB Horticulture is funding the production of Blackcurrant Gall Mite Emergence Charts. These are produced to help guide UK blackcurrant growers when to apply control measures for blackcurrant gall mite, as they emerge from over-wintering in ‘big buds’.
Click here to view the latest charts.
The 100 line on the graph represents first mite emergence and has proved accurate to within 3 days each year over the last decade. Growers are normally advised to apply control treatments just before the line reaches this mark. The transition of the graph to the blue section identifies when 50% of the mites have emerged and growers have generally aimed to apply their second control treatment just ahead of that time, although applications need to be made by ‘first grape visible’ to avoid the possibility of yield loss.
Growers should be guided on the exact timing of control treatments and the choice of product by a BASIS qualified fruit consultant.