Sanitiser and wound protectants - important game-changers
Following a year where every month in every region could be described as ‘wet or wetter’ it is important that growers focus on excellent orchard hygiene practices through winter pruning, grafting, and planting periods.
Unusual symptoms reported over the past six months included more observations of armillaria fruiting bodies, slime moulds, and other common fungal species such as Pore conch. These are all visual indicators of the effects of a wetter world and provide a heads up that conditions have suited many fungal species. We need to actively manage this heightened risk of fungal infections, many of which may not show until spring or beyond.
Previously, the Gold Futures Psa research project showed infection cut-out, sanitised tools and wound protectants were game changers in management of Psa, all helping to break the disease cycle. Similarly preventative practices of applying pruning-wound protectants and good tool hygiene are proven in the management of fungal diseases, e.g., against Eutypa in the grape industry, and European Canker in apples.
Fungal infections on kiwifruit vines and in stumps or prunings left in the orchard can survive for long periods and over time reproductive structures develop on the surface of the infected wood. These produce spores which when triggered release into the air. Spore release generally occurs during wet periods, so pruning being completed is a high-risk time. Spores carry considerable distances by air currents and can quickly infect new or recent wounds.
Kiwifruit research projects on Neonectria microconidia found unprotected pruning wounds were often closely associated with the canker symptoms of this disease. Growers managing Neonectria have also seen reduced impact when tools are sanitised, and wound protectants are used.
Information on orchard hygiene and sanitiser lists can be found here.