La Crescent is a cold climate grape variety developed by the University of Minnesota and well adapted to production in Wisconsin. La Crescent is very cold hardy and disease resistant and has many other positive characteristics. One issue with La Crescent is that the grape will shatter (berries fall off easily) at harvest time. Heavy winds, delayed harvest due to rain, and mechanical harvesting are all risks to the economic success of using this variety. There is some observations in the grape industry that higher levels of calcium and adequate levels of nitrogen may significantly reduce shatter in La Crescent grapes. This proposal would conduct replicated trials using recommended levels of nitrogen and increased levels of both soil applied and foliar applied calcium. Tissue levels of both nitrogen and calcium will be measured through lab petiole tests and hand held sap testers.
Project objectives from proposal:
- Determine if handheld nitrogen and calcium sap testers are accurate in getting immediate field levels as compared to lab petiole tests.
- Evaluate if high levels of soil applied calcium and foliar applied calcium reduce shatter in La Crescent Grapes.
- Measure grape juice quality on all treatments.
- Share data following year one and year two with grape growing organizations in Wisconsin and Minnesota and on social media.