Apple scab and bacterial fireblight need frequent consideration in high density apple orchards. These close proximity and high growth-rate systems often have a drawback of increased disease management effort. Non- chemical diseases control includes removing surrounding source-wood for these pathogens and insect vectors, planting disease-resistant varieties/rootstocks, and frequent scouting to remove infected parts of the trees.
Exclusion netting has been popular in Canada and France for reducing insect damage on apples at critical control periods and has shown promise in protecting blueberry crops from insects in the U.S. This cultural control has also shown promise for controlling apple scab in published research, while there isn’t much data on fireblight control. Theoretically, netting will reduce wind, rain and insect transport for the bacteria that causes fireblight. This has promise for producing organic high density apples in moist environments where fireblight occurs, as Streptomycin and Kasumin, are not organic certified. Queva, Double Nickel and Serenade are OMRI listed but less effective. They could have greater fireblight control activity in combination with exclusion netting. We will compare different netting materials and combinations of conventional and organic products to control these diseases and try to identify or reduce technical and labor hurdles to using netting.
Project objectives from proposal:
1: Evaluate three different commercial exclusion nets and no-net control for durability, micro-climate effects, insect exclusion, and wind and rainwater passage factors at all three farms.
2: Test different fungicides and bacteriocides with the three exclusion nets and a no-net control in statistically significant tests to compare outcomes at three different orchards.
3: Investigate solutions to make exclusion netting easier to use in high-density orchards. Designs to pull the netting back over rows, open on one side, or have seal-able openings can make them practical.
4: Share findings through field days, website and social media, conference presentation.