West central Michigan vegetable regional report – May 13, 2015
Crop progress is ongoing, early planted vegetables are emerging and planting of others is to come. Be on the lookout for early season pest activity.
Asparagus harvest was ongoing with rapid spear growth through this past weekend due to warm weather. Crop consultants reported a first sighting of a common asparagus beetle adult as of last Thursday, May 7. Formulations of the active ingredient carbaryl (one- day pre-harvest interval, or PHI) can be used for control once beetles become more abundant and egg-laying starts.
Carrot planting is complete for some processing varieties with crops emerging. The main focus at present is application of herbicides.
Cole crop early season pests could be active. Growing degree day models suggest cabbage maggot adults have started emerging in the Hart, Hudsonville, Sparta and Standale, Michigan, areas, with peak flight and egg-laying upcoming. At-plant treatments can protect your transplants. Michigan State University Extension advises growers to be on the lookout for slug activity; check the base of your plants in the morning for slugs. Deadline Bullets (active ingredient, or a.i., metaldehyde) can be used by conventional growers for control. Iron phosphate products are available for organic growers.
Cucurbit planting should start for winter squash varieties over the next two weeks in Newaygo County locations.
Onions are in various stages across the region; wet fields are making fieldwork challenging in some areas. Remember that Goaltender (a.i. oxyfluorfen) has a 24(c) label for application to the one leaf stage, which could enable growers to get small, recently germinated weeds while they are more vulnerable to herbicides.
Growers may consider incorporating the herbicide Chateau into herbicide programs for onions on muck soils once onions are in the three to six leaf stage. It can be tank-mixed with one of the applications of Prowl H20, but not other formulations of Prowl. It has post-emergence activity on some problem weeds not picked up as well by Goaltender, including smartweeds, ladysthumb and lambsquarter, and pre-emergence activity on some weeds. Read the MSU vegetable herbicide guide for more details. Make sure to read the label and, as always, be aware of potential for crop injury when trying new herbicides.
Pepper transplanting will likely begin in the next few weeks.
Potato planting has been ongoing.
Sweet corn early season pests could be active. Recent storm fronts could have brought black cutworm or true armyworm moths into the area. Watch for clipped plants - a symptom of cutworm activity - over the next few weeks and dig up soil around the base of plants to determine if larvae are present. True armyworm is a defoliator that is often worse in areas with weedy grasses as females lay eggs on these plants.