Pheromone-based mating disruption
Trials of a pheromone blend targeting the top three lepidopteran pests in Wisconsin cranberry (blackheaded fireworm, cranberry fruitworm, and Sparganothis fruitworm) were conducted in 2012 and 2013. The pheromone carrrier is a paraffin emulsion, trademarked as SPLAT (Specialized Pheromone & Lure Application Technology).
Benefits of SPLAT:
Flooding as an IPM tactic
Field study: submergence tolerance
In 2011 we did the “bug flood” project to examine the effects of a mid-spring flood on the cranberry plant, as well as on key insect species. Timing of the flood (for fireworm egg-hatch) and duration of submergence were key factors in the study. A total of 46 commercially managed beds were included in the study (11 growers). Findings suggest that a 30-40 hour flood may cause mild stress to the plant, causing reductions in flowers/upright, but by fall, harvestable biomass was similar among flooded and non-flooded beds. Black-headed fireworm flights were significantly reduced in flooded beds.
Cranberry bed, mid spring, as the flood waters rise
Water levels rising
Measuring water temperature and dissolved oxygen in a completely submerged bed
Greenhouse study: submergence tolerance
In addition to assessing plant tolerance to submergence conditions in the field, we wanted to measure absolute tolerance of cranberry. In greenhouse trials we assayed which factors drive the submergence tolerance of cranberry varieties. Three cranberry varieties common in Wisconsin (‘Ben Lear,’ ‘Stevens,’ and ‘GH1’) were examined, and water temperature (cool, warm) and submergence duration (0, 48, and 96 hours) were fully crossed. Plants were followed for two months post-submergence to track long-term effects.
If you are interested in learning more about this project, see our presentation on it:
Overwintered cranberry sods were dug up from commercial beds, and then potted for the submergence trials
Aquaria were set up to allow replicated manipulations of temperature and submergence duration
Potted cranberry sod completely submerged in water
We did another study looking at the types and numbers of arthropods removed from beds along with “trash” in the spring trash floods. This is when growers briefly flood beds to get decomposing plant matter out. See page 3 in Volume XXV Issue 7 of Cranberry Crop Management Newsletter for our article on it:
Cranberry flea beetle biology and management (ongoing project)
Newly Funded Research May Help Squash Major Cranberry Pest: click here to read WPR’s coverage of the Steffan lab’s exciting news about flea beetle research.
Tim Dittl, Agricultural Scientist, Ocean Spray Cranberries, Inc.
Jayne Sojka, Owner and Consultant, Lady Bug IPM
ISCA Technologies, Riverside, CA, USA