Northwest Michigan fruit update – May 30, 2017

Grapes are showing variable growth, and rains triggered release of powdery mildew spores.

Editor's note: A detailed grape and saskatoon update are only included in this week's northwest Michigan fruit update. Growing degree-day accumulations and fruit growth stages are also included.

Growing degree day accumulations as of May 30, 2017 at the NWMHRC

Year

2017

2016

2015

2014

2013

2012

27 Yr. Avg.

GDD42

589

626

626

460

548

948

599.7

GDD50

276

325

333

217

303

531

300.4

2017 growth stages as of May 30, 2017

  • Bartlett Pear – 9 millimeter fruit
  • Potomac Pear – 7 millimeter fruit
  • Mac – 7 millimeter fruit
  • Gala – 6 millimeter fruit
  • Red Delicious – 6 millimeter fruit
  • HoneyCrisp – 7 millimeter fruit
  • Montmorency – 8 millimeter fruit
  • Balaton – 8 millimeter fruit
  • Hedelfingen – 11 millimeter fruit
  • Gold – 10 millimeter fruit
  • Napoleon – 11 millimeter fruit
  • Riesling – 1 inch – 3 inch shoots

Wine grapes

Riesling vines at the Northwest Michigan Horticultural Research Center are showing variable growth, with anywhere from 1 to 6 inches of shoot growth. Recent rains in the Grand Traverse region were sufficient to trigger the release of powdery mildew spores.

The First Friday Meeting for June will he held this Friday, June 2 from 3 - 5 p.m. at the Northwest Michigan Horticultural Research Center, 6686 S. Center Highway Traverse City, MI 49684.

The topic will be "Dealing with Sour Rot in Grapes", presented via ZOOM by Wendy McFadden-Smith, PhD. McFadden-Smith is the Tender Fruit and Grape Integrated Pest Management Extension Specialist with Ontario Ministry of Agriculture, Food and Rural Affairs in Vineland, Ontario. She has a PhD in plant pathology from the University of Saskatchewan and an MSc and BSc (Agr) from the University of Guelph. She has been involved in pest management in tree fruit, grapes and small fruit for the past 27 years. As an adjunct professor, she lectures in the Department of Biological Sciences and a professional affiliate of the Cool Climate Oenology and Viticulture Institute at Brock University.  Her research projects deal with sour rot and its vectors, grapevine viruses and their vectors, grape berry moth, black knot in plums, fire blight in pome fruit, bacterial spot in nectarines and anything else that wreaks havoc and destruction on tree fruit or grapes.

Saskatoons

The egg laying activity of apple curculio and saskatoon sawfly continued during the last week. Foliar symptoms of woolly aphids are now showing. The injury from these insects is not usually severe enough to be a concern. Recent rains likely resulted in infection periods for entomosporium leafspot and saskatoon-juniper rust.       

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