West central Michigan vegetable regional report – May 15, 2013
West central Michigan saw a major freeze this past weekend that impacted vegetable production.
Mid-week weather summary
The most important weather event since last Wednesday (May 8) was the major freeze that occurred across Mason, Oceana and parts of Newaygo County late Sunday into Monday morning (May 12-13). In these counties, Enviro-weather stations recorded air temperatures in the 20s that persisted for multiple overnight hours. Temperatures in Ottawa and Kent counties were more moderate, with lows at Hudsonville and Sparta in the 30s and fewer hours of below-freezing temperatures.
Jeff Andresen, our Michigan State University Extension agricultural meteorologist, noted that we are unlikely to see a major freeze event again this year, as this would require a major change in upper atmosphere weather patterns. Warmer than normal temperatures and dry weather are expected to persist today through Sunday (May 15-19), with a chance of scattered showers Friday evening (May 17). Temperatures may cool to a few degrees below normal early next week with significant chances for precipitation on Monday, Tuesday and Wednesday (May 20-22). Temperatures are then expected to warm later next week.
The National Weather Service’s 6-10 and 8-14 day forecasts call for above-normal temperatures and precipitation for May 20-24, which covers next Monday through Friday, and normal temperatures with above-normal precipitation for May 22-28, which covers next Wednesday through the last week of May. Andresen noted that weather patterns at this time of year are in transition and unpredictable, and that this forecast could change.
In Oceana County, some growers made one to two pickings of asparagus and stripped their fields prior to this weekend’s freeze event, while others did not. Temperatures Sunday night and early Monday were much colder than forecasted, which killed all spears emerged over 0.25 inches. Many growers mowed this freeze-killed asparagus since dead spears harden and can cut pickers’ hands, in addition to making picking healthy spears more challenging.
White cutworm damage to spear tips was observed by one grower over the weekend. Insecticides that are applied over the next few days to control white cutworms may also kill dark-sided cutworms, which may become active soon and damage the base of spears. A threshold of 5 percent damaged spears can be used to decide whether or not cutworm control is warranted. Growers should continue to be on the lookout for common asparagus beetles.
As of Monday, carrots had either germinated but not emerged, or were in the rabbit-ear stage in Oceana County. In field visits Monday, there was no evidence of major freeze-damage to seedlings.
As of last Thursday (May 9), onions had either germinated but not emerged, or were in the loop or flag stages in Hudsonville, Mich., and Byron Center, Mich. Growing degree day models suggest that peak egglaying by seed corn maggots started the second week of May in Hudsonville, Mich., and Fremont, Mich. Damage done by hatching larvae should now be evident.