West central Michigan small fruit regional report – July 7, 2015
Strawberry harvest is ending and blueberry hand harvest is in full swing with good quality.
Small fruit crops, mainly strawberries, blueberries and raspberries, are at different harvest stages in west central Michigan. Despite some early problems with winter and disease damage, yields and fruit quality for harvested strawberries were good. Raspberries, on the other hand, just started ripening and some small quantities are being harvested around Ottawa and Allegan counties. Currently, fruit quality and yields are good, and no problems have been observed by growers.
Harvest of early blueberry varieties has continued in Allegan, Van Buren and other southern counties. Fruit quality is very good in fields that had minimal problems with winter damage. During the last two weeks, the daily maximum temperature averaged 79 degrees Fahrenheit and the minimum temperature averages 55 F with some sporadic rains that left an accumulation of 1 inch or more in some areas. These sporadic rains and environmental temperatures in the lower 80s brought favorable conditions for good fruit growth and development.
Regarding insect and disease problems, the effects of Phomopsis canker is showing with more intensity in fields affected by winter damage and in fields with limited disease management. Growers that were not aware of the presence of Phomopsis and whose fields sustained important winter damage are seeing entire plant rows collapsing at this time. Also, incorrect fungicide applications, using a protectant fungicide like Captan instead of Indar, Quash or Pristine, which are systemic fungicides, also contributed to the extent of the damage.
At this time, Pristine can be applied to prevent further infections on new shoots and mature canes. Quash can be applied, but there is a seven-day pre-harvest interval (PHI). That will be useful for mid- and late-season varieties that are not ready for harvest. These two fungicides will not only prevent further Phomopsis damage, but will also provide good control for Alternaria and Anthracnose fruit rot. For more options and recommendations, please consult the “2015 Michigan Fruit Management Guide,” Michigan State University Extension Bulletin E0154.
Currently, spotted wing Drosophila (SWD) continue to show up in west central Michigan. SWD has been detected in strawberries, raspberries and blueberries in Ottawa County, and this week it was trapped in substantial numbers in Allegan County in blueberries. However, no fruit infestations have been reported. Growers need to remember there is not an established number of flies that need to be trapped before starting SWD control. The earlier the population is controlled, the better. Therefore, if you have observed the arrival of the first flies in your traps, consider initiating chemical control. Before making the decision to spray, please check the MSU Enviro-weather advanced weather forecast to select the best insecticide for the forecasted conditions of temperature and probability of rain.