Fruit and Vegetable News

Author: Natalie Hoidal, UMN Extension educator, local foods and vegetable crops  This week has brought some welcome respite from the heat and humidity, but drought conditions have persisted across much of the state. Crops seem to be responding well to the lower temperatures this week, with a few exciting new crops reaching maturity. As we shift into late summer, keep your eyes out for some important late summer insect pests. Problems in the field / things to note this week Are your plants getting enough water?  Most growers have heard the phrase "an inch of water per week" as a guideline for watering vegetables. However, an inch may not be enough for some vegetables, particularly during hot weather and fruiting. I discovered a helpful chart this week from University of Missouri outlining the water requirements for high tunnel tomatoes at different growth stages. The article also has some helpful charts for figuring out how much water you're giving each plant based on your

Photo: The Minnesota Apple Growers Association held their annual farm tour at the Horticulture Research Center on Friday, July 22.   Author: Annie Klodd, Extension Educator, Fruit and Vegetable Production. kloddann@umn.edu This week's update includes apple pest management, grape veraison, raspberry and blueberry harvest seasons, and day neutral strawberry troubleshooting. First, are we in a drought again? Many areas of Minnesota are getting a welcome break after last year's drought, and the metro area is experiencing deja vu from last year. The Drought Monitor map below shows that areas southwest of the metro are in moderate or severe drought, while northern Minnesota has no drought conditions. Some of us are getting tired of irrigating, aren't we? At least, one nice thing about the lack of rain is a lack of disease pressure.  Drought Monitor map for Minnesota, showing a range of drought intensity from "none" to "severe" across the state. https://drought

  Photo: A strawberry field after harvest and before renovation Author: Annie Klodd, Extension Educator - Fruit and Vegetable Production This update discusses: how climate change is impacting berry production; mid-season apple pests; and last call for grape nitrogen applications. Strawberry renovation was discussed in the last update and is still relevant though the content is not repeated in this article. Apples  Pests that have entered the game this month: Woolly apple aphid - the white aphid colonies can be seen on apple tree shoots and watersprouts. Yesterday, we saw a beneficial predator, syrphid fly larvae, approaching a colony of aphids to feed on them. Syrphid fly larvae can consume all or part of a colony. Avoiding broad-spectrum insecticides early in the season, and avoiding unnecessary insecticide applications can help preserve beneficial insects including syrphid flies, green lacewings, and European earwigs. Syrphid fly larvae crawling over to feast on woolly apple aphid -

Author: Natalie Hoidal, UMN Extension educator, local foods and vegetable crops  The main story this week is the heat. Keeping yourself and workers safe can be challenging during intense heatwaves, and plants are struggling to keep up. We also experienced the first wildfire smoke related air quality effects this season, and forecasters are predicting that we may see more air pollution in the coming weeks. Problems in the field / things to note this week Expect limited fruit set in tomatoes, peppers, zucchini, cucumbers Hot weather, especially when it remains hot at night, is bad news for many vegetables. The heat causes a variety of problems including flower and pollen deformation, changes to the ratio of male to female flowers in cucurbits, and poor pollination due to decreased pollinator activity. High heat can also interfere with fruit maturation. Due to the current heat wave, expect more fruit and flower abortion, and delays in ripening. You can read more about these issues

  Marissa Schuh, IPM Extension Educator, mschuh@umn.edu Growers are reporting large, colorful caterpillars hanging out in groups on assorted crops.  They are most often being seen brassica crops, though they have been spotted feeding on strawberries and tomatoes. Large and colorful, zebra caterpillars are easy to spot. Photo: Marissa Schuh, UMN Extension. The large, colorful caterpillars are zebra caterpillars.  These pests seen only occasionally on vegetable crops, most often in brassicas. They have distinctive yellow stripes running down their body, and if you look closely, you will see the repeating black and white strips that give them their name. Young caterpillars are often found in a clustered area of the field, as the moths lay their eggs in a group and the caterpillars don't mind all feeding together once they hatch. As the caterpillars grow, they spread out a little bit and feed singly. The damage they cause is typically pretty minor.  They may attack a few plants heavi

  Author: Shane Bugeja, Extension Educator, Blue Earth/Le Sueur Counties, sbugeja@umn.edu The University of Minnesota Extension will host a free, virtual program focusing on grafted tomatoes and their effects on production and nutrient management. All commercial horticulture producers are welcome to attend. Grafted tomatoes have been mentioned as a solution to many issues that pose challenges to farmers. What does the research say, and how can one use these plants in their operation? Speakers include Dr. Ajay Nair, Iowa State Extension Vegetable Specialist. Dr. Nair will list specific rootstocks and scions, discuss grafting techniques, and highlight findings from Iowa State. Charlie Rohwer, UMN Horticultural Scientist, and Shane Bugeja, Local Extension Educator, will present Minnesota-specific data regarding grafted tomatoes, interactions with starter fertilizer, and grafted tomato effects on phosphorus managem