Fruit and Vegetable News

Madeline Wimmer- UMN Fruit Production Extension Educator This fruit update contains information about… Apples   About: Moldy core  Apple maggot status Grapes Current growth stage About: Insect galls Grape tumid gall Grape filbert gall Day-neutral strawberries   2024 growing season  Anthracnose fruit rot  Tarnished plant bug  Apples Image: Moldy core is a general condition in which fungi enter through the apple calyx and colonize the ovaries and developing seeds. Photo taken by a Minnesota apple grower from Chisago County.  Moldy core This week, there was a report from a Minnesota orchard that observed some apples that were ripening earlier than others. When cut open, there was noticeable mold within the apple ovaries on developing apple seeds. While there existed what looked like a codling moth exit hole, no frass was apparent and the actual mold within the ovaries was a sign that the apple was infected with moldy core : a condition caused by fungi that enter apples through the calyx e

Authors: Marissa Schuh and Natalie Hoidal Minnesota has had pretty minimal days under 90 until the tail end of last week, when heat and humidity moved in. UMN Extension has developed guidelines around how often to rest and drink water, you can find those here . For how this heatwave may affect some of our vegetable crops, you can read a refresher here . We are on tap for some extreme winds. If you are seeing plant damage, timely applications of copper and fungicides can help protect the plants from pathogens. For more information on how strong winds can impact vegetables at this point in the season, see this article from Iowa State. Some generalist diseases In the last week we have gotten reports of a couple of moisture-loving pathogens that affect a wide range of vegetable crops. Both of these diseases can survive for a long time in our soil, so quick detection and removal of infected plants can help reduce the amount of the pathogen you have going forward. Phytophthora This long-l

Author: Marissa Schuh , Integrated Pest Management Extension Educator, University of Minnesota Extension. Reviewed by Natalie Hoidal. Originally publishes July 2021, updated July 2024. We are hitting the growing season's first heat wave. While the last few years have been hot, you can refresh yourself on the ways hot weather can change the way our crops grow and yield. Ways hot weather impact crops before fruit set Potential issue 1: Hot day and nighttime temperatures cause flowers to drop Aborted flowers wither and become brittle, falling off the plant easily. Photo: Marissa Schuh, University of Minnesota Extension If you are still seeing flowers, but aren’t getting the tomatoes, peppers, beans or zucchini you are expecting, there can be a few heat-related factors in play. The first is flower abortion: flowers form, but then die and fall off the plant before becoming fruit. Flower abortion can happen at temperatures ranging from 75° F to 95° F. Dropped flowers have been noticeab

Madeline Wimmer- UMN Fruit Production Extension Educator This fruit update contains information about… Apples - cider apple production. Grapes - growth stage updates and herbicide damage on grapes. Raspberries - growth stage updates. 2024 Japanese beetle trends and research updates. Apples Images: A small capture of the diverse number of apple cultivars used for cider production at Keepsake Cidery’s orchard, including Centennial Crabapple (upper left), Ellis Bitter (upper right), and Foxwhelp (lower left), located near Northfield, Minnesota (Zone 5a). What constitutes a cider apple? How cider apples are classified is somewhat subjective based on the goals of a cider maker. Some traditional cider apple cultivars originate from regions historically known for their cider production, such as the United Kingdom and France. But what makes apples like Dabinette or Ellis Bitter different from something like a Honeycrisp apple? Apples that have been bred and selected for fresh eating and proces

Authors: Marissa Schuh and Natalie Hoidal General Notes Some areas continue to get heavy rainfall, other parts of the state are drying out. The NOAA forecast for August is calling for a slight chance of above normal temperatures, and a normal amount of rain . Plants on some farms, and maybe in every farm’s low spots, are struggling. The below picture from Purdue University highlights how different crops are affected by waterlogging. The crops on the left side were submerged in water for three days, while the three on the right were grown in optimal conditions. Waterlogging in vegetable crops. Photo: Wenjing Guan, Purdue University. Crop Updates Bean : Harvest continues. I have gotten pictures of some leaves with yellowing and scorched edges. A potential culprit is leafhoppers, particularly potato leafhopper. This leafhopper makes it’s way up to Minnesota each summer, and uses it’s straw-like mouthpart to feed on plant juices. While they don’t spread disease, their feeding produces

Author: Marissa Schuh , Integrated Pest Management Extension Educator, University of Minnesota Extension. Reviewed by Natalie Hoidal. Originally published July 14, 2024. Updated July 22, 2024. Minnesota sweet corn is making its way to markets. Plantings will continue to tassel, silk, and size up ears for the next two months, meaning we are entering the key window for sweet corn pest control. The insects you may see but may not need to manage Adult corn rootworm beetles feeding on silks. Photo: Natalie Hoidal. Field crops extension educators are starting to detect the emergence of corn rootworm. You might see these yellow and black beetles clustered on silks or even feeding inside pumpkins flowers. These beetles can reach high numbers, but tend not to be an issue in sweet corn. They do the most damage as larvae, feeding on corn roots (hence the name). Beetles lay eggs as the base of corn stalks, and larvae hatch the next year and feed on corn roots. This means that rotation can effe

Marissa Schuh, IPM Extension Educator, mschuh@ umn.edu Tomato might be the spottiest vegetable we grow – there are many diseases that can cause leaf spots, and they can all look very similar. Some of the diseases are caused by bacteria, some are caused by fungi. This means that some of the same cultural practices may work, but if you are thinking about chemical controls and longer term management, knowing which pathogen you have will be important.   Early blight attacks the oldest leaves first. Photo: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org Fungal pathogens We have two fungal diseases we commonly see causing leaf spots in Minnesota – early blight and septoria leaf spot. Early blight is very common. The pathogen survives in crop debris and weeds, then infects plants by splashing up into the foliage. This means that the first part of the plant infected is the oldest leaves. Infected leaves develop brown spots, and if you look closely at these spots, the

  Annalisa Hultberg, Extension Educator, food safety Agritourism and U-pick farms may have different food safety risks and considerations than traditional fruit and vegetable farms, since the general public (who may not be well-versed in food safety considerations) are being invited to the farm.  Here are some key recommendations to keep your produce safe for U-Pick and orchards this summer and fall. Photo: Annie Klodd What are the risks? Many bacteria like  Salmonella ,  Campylobacter  and  E. coli  can be spread to fresh produce from animals and sick humans. Viruses like Norovirus and Hepatitis   can easily transmitted between humans via fresh produce and other food, surfaces and the air.  These bacteria and viruses can seriously sicken people, especially the young, old, and immunocompromised.  There have been outbreaks at agritourism farms, especially those that have animals. Take some basic precautions to reduce the potential for these illness to be spread on your farm. Some of the

Madeline Wimmer- UMN Fruit Production Extension Educator This fruit update contains information about… Apples- second generation codling moth. Grapes- disease updates and russeting and cracking. Blueberries- harvest season and insect pest updates. Additional fruit updates- black currants, aronia berries, and kiwiberries. Apples Images: Apples showing fruit color development as they continue to ripen at Keepsake Cidery near Northfield, MN (left image; Zone 5a). Cutting open an apple with a visible entry point can reveal evidence of larval damage within a developing apple showing leftover frass and damage to the ovaries and developing seeds (right image). Second generation codling moth The second generation of codling moth adults are typically expected to emerge around 1,060 degree day units (DD) after the first biofix date, which was recorded when the first generation codling moth adults were initially trapped. The University of Minnesota Horticulture Research Center (UMN HRC) is foreca