West central Michigan small fruit regional report – July 22, 2014
Blueberries are in full harvest with very good quality and yield. Spotted wing Drosophila have been limited to a few specimens in some fields. Summer raspberries are also in harvest with no problems except for a few SWD that are under control.
Weather conditions this past week have been favorable for a good berry harvest for both raspberries and blueberries. There were several days with dry conditions that prompted blueberry growers to supplement the fields with irrigation. However, in general the conditions are conducive for maintaining a good fruit quality for this portion of the harvest season. Weather for the last seven days has been benign with daily maximum temperatures averaging 76 degrees Fahrenheit and a minimum temperature of 53 F.
So far, few problems are reported by growers harvesting raspberries and blueberries. In a few instances where spotted wing Drosophila (SWD) has been observed in the traps, the corresponding chemical control measures have been applied. This has allowed excellent control of this pest with no reports of fruit damage in raspberry or blueberry fruits.
It is important to remember that early detection and control of first generation SWD is critical to maintain good pest control throughout the season and avoid fruit infestations at harvest. If SWD flies are detected in your field and you need to apply insecticides, make sure you take into consideration the weather conditions at the time of the application and during the expected protection period. High daily temperatures greater than 90 F tend to reduce the effectiveness of pyrethroids. The same is true for Malathion. So, check the weather, and if the daily temperatures or rainy conditions may affect the durability of the insecticide you applied, repeat the application with a different insecticide. For insecticides and doses, see “SWD Management Recommendations for Michigan Blueberry.”