Fruit and Vegetable News

 Article written by Madeline Wimmer, UMN Extension Fruit Production Educator Blueberries Growth stage: Fruit harvest for early hybrid and highbush varieties SWD updates and exclusion netting Disease: Anthracnose fruit rot Grapes Japanese Beetle: First sighting of the year and the winsome fly parasitoid Optimal timing for basal leaf and lateral shoot removal Pears Variety highlight: Summercrisp Black currant Growth stage: Ripening Blueberries Growth stage: Fruit harvest for early hybrid and highbush varieties Images: Blueberries are coming into harvest season at farms in southern Minnesota, including Blue Fruit Farm, near Winona and Little Hill Berry Farm in Northfield. Here pictured Northland (left) and Polaris (right), both hybrid blueberry varieties. We’re coming up on the start of harvest season for blueberries in southern Minnesota where both hybrid (half-high) and highbush blueberries are planted. Blueberry production in these regions often requires monitoring of the soil pH a...

  Article written by Madeline Wimmer, UMN Extension Fruit Production Educator Image: A grape shoot node anatomy includes the region with a developing bud (B), lateral shoot (Lat), leaf (L), and tendril (T).  Basal (i.e., around the cluster zone) leaf and lateral shoot removal is a simple, low-input practice that removes leaves and lateral shoots from the lower nodes near developing clusters. This can enhance fruit quality by increasing air flow and direct sunlight exposure on developing fruit clusters and basal buds, which give way to shoots and clusters the following growing season. Basal leaf and lateral shoot removal also increases spray penetration for products like fungicides, etc. The timing in which basal leaf removal is completed can make an impact. Leaf thinning has traditionally been done after fruits have set, with some research in Michigan looking at the benefits of pre-bloom thinning (see end of article for more information). Research done in the Upper Midwest on ...

Authors: Natalie Hoidal & Marissa Schuh After a hot start to the week, we are settling into temperatures that are a little more typical for July. Heat waves can slow down our vegetable crops in a few ways, see a rundown in the article “ How vegetables respond to heat .”  In general, when we have hot days, and especially hot nights, there is reduced fruit set in vine crops and tomatoes, as well as a slow down in tomato ripening.  Mid to late June is one of our favorite times of year. The big push to get everything planted is winding down (though succession planting continues), and we’re seeing the shift from just harvesting spring greens into early summer crops like carrots, beets, summer squash, etc. This is also when things start to get “interesting” in the field. We’ve had calls this week about hail damage, herbicide drift, disease, insects, some potential ozone damage, miscalibrated fertigation, and some nutrient deficiencies. Thankfully, at this time in the season the...

Article written by Madeline Wimmer, UMN Extension Fruit Production Educator Images: Exclusion netting is one method to manage spotted wing drosophila (SWD) from blueberries and other fruit crops (left). A map provided by the Vegetable Disease and Insect Forecasting Network can give insight for SWD population pressure in various regions in the Upper Midwest (right).  Right now, spotted wing drosophila (SWD) populations are forecasted to be at lower levels in southern Minnesota, and very low for regions that are north of St. Cloud. In general SWD populations can vary at different farm sites based on the existence of wild berries within forested edges, for example, other susceptible crops grown on site that have already ripened, along with overall management practices, and other environmental conditions.  SWD has been a major disruptor to vulnerable crops like raspberries, which were previously grown with less requirement for insecticide inputs before SWD’s arrival. There has bee...

Article written by Madeline Wimmer , UMN Extension Fruit Production Educator Images: Pollinator resources often recommend planting at least three species of pollinator friendly plants, specific to your crop and region, for each bloom period (early, mid-season, late). Introduction Successful pollination is key for quality fruit production anywhere in the world. When fruit set is lower than expected, or other aspects like fruit shape and size are impacted, there are a number of factors that could be contributing, depending on which fruit crop you’re growing:  Very few fruit crops are wind pollinated (one example is grapes), while the majority of fruit crops rely on, or benefit from insect pollination, primarily bees, for successful fruit set, adequate sized fruits, or even shaped fruits. Some fruit crops are self-incompatible, which means they will not use their own pollen for pollination. Successful cross pollination happens when two varieties have overlapping bloom times. Addition...

  Article written by Madeline Wimmer, UMN Extension Fruit Production Educator. Image: Japanese beetles have a wide host range and are a common pest of grape leaves in Minnesota and the Upper Midwest.  I spotted my first Japanese beetle for the year in SE Minnesota on Tuesday 06/30. Japanese beetles have been an invasive pest in Minnesota since the late 1960s and have increasingly become a pest in vineyards for the past 10-15 years. They have over 300 known host plants, commonly impacting the foliage and occasionally fruit for some crops like peaches and raspberries.  Even though many grapevines can withstand a certain amount of defoliation from Japanese beetles, early management is often important. Japanese beetles create a positive feedback loop as foliar damage increases, which releases volatile organic compounds. Additionally, as more beetles gather and begin to mate, their pheromones continue to attract more beetles on site. Adult grapevines can usually handle feedin...