Southeast Michigan fruit regional report – June 20, 2014
Primary apple scab season is now over for East Michigan, gray mold is being seen at a few strawberry farms, and growers are reminded about hail and fire blight.
Editor's note: This report was updated Monday, June 23, 2014 to contain new information on berries, apples and pears.
With two good rains on Wednesday, June 18, 2014, at the apple scab spore trapping station in East Michigan, there were no apple scab spores caught in either event. Thus, we are now at the end of primary apple scab season in East Michigan. For apple growers, this means that if they have apple scab under control at this point of the season, that they can now relax their apple scab control program.
Gary mold has been reported by a few growers as berries are being harvested. While this disease usually infects the fruit at blossom time, it frequently does not become visible until harvest. I encourage growers to do a thorough job of scouting their fields for the gray-brown, fluffy fungal growth on berries. Consider holding a small sample of harvested berries for a few days at room temperatures for signs of the fungal growth. If found, consult the 2014 Michigan Fruit Management Guide (E154) from Michigan State University Extension for specific fungicide recommendations. Some of the newer fungicides targeted for gray mold are a good choice to control this disease. Be sure to consult the pre-harvest interval chart as well if making a fungicide selection.
Hail has been reported by a number of fruit growers in thunderstorms that have moved through the region this week. Hail stones hitting fruit and limbs of apple and pear trees causes small openings that are possible entry points for fire blight bacteria. As a reminder to apple growers who have had the misfortune to have a hail event at their farm, streptomycin needs to be applied within 24 hours of the hail event to help prevent fire blight infection.