A two-year investigation into apple canker management has identified actionable strategies to lower tree mortality and trunk cankers in newly planted orchards by 50%. The project was an industry collaboration involving Niab, Avalon Fresh, and Agrovista, supported by Growing Kent & Medway, and aimed to explore novel methods for managing apple canker and tree stress from drought and waterlogging. Canker, a disease affecting young apple tree trunks, leads to tree death and financial losses for growers.
The trials evaluated various options, including adding beneficial microorganisms to soils and utilizing bio-controls. Results indicated that introducing mycorrhizal fungi and Trichoderma, a biocontrol organism, to soils during orchard planting significantly reduced tree mortality in the first two years. These fungi enhance water and nutrient uptake, increasing resilience to weather, pests, and diseases. The treatments proved more effective in orchards with high canker presence and stressed trees, without impacting fruit yields.
Alex Radu, Technical Manager for Agrovista, noted, "We've long felt that the interaction between mycorrhizal and Trichoderma fungi could be beneficial in helping fruit trees respond to canker, but haven't had the evidence to prove this until now." Dr. Matevz Papp-Rupar from Niab added, "The trials show that the mycorrhizal fungi amendments won't control the canker, but they can make the trees more resilient to the effects of the disease, significantly increasing their ability to survive and mature." He emphasized maintaining robust management, including orchard hygiene, to minimize disease presence.
The research also explored methods to incorporate amendments into mature orchards. Strategies included planting wildflower strips with mycorrhiza and using a modified root pruner to apply mycorrhiza directly during root pruning. Wildflowers, more effective than grass at associating with mycorrhizae, could enhance orchard resilience to canker and stress. Both methods increased mycorrhiza presence, offsetting growth and yield reductions from root pruning, and enhanced apple sweetness.
Nigel Jenner, Chief Technical Officer for Avalon Fresh, remarked, "The project has yielded successful results, providing valuable insights and practical solutions for fruit growers." Dr. Louisa Robinson Boyer from Niab highlighted the importance of improving soil biodiversity and health in established orchards through mycorrhizal fungi incorporation, noting the project's data as a foundation for future research.
Source: Growing K&M