Fruit and Vegetable News

Madeline Wimmer- UMN Fruit Production Extension Educator Apples : Growth stage updates: Apples between 12–24 mm, rapid shoot growth Removing newly emerging water sprouts Apple scab update Grapes: Growth stage update: 6–8 leaves separated  Bloom: Petiole sampling for nutrient analysis Berry crops: Pest highlight: Spotted Wing Drosophila (SWD) About SWD Monitoring SWD adults and larvae Managing SWD Apples Growth stage updates: Fruitlets between 12–24 mm, rapid shoot growth Images: A step by step demonstration of hand removal of a newly emerging water sprout from a larger scaffold branch on a freestanding central leader trained apple tree. Image from Sekapp Orchard in Olmsted County, MN (Zone 5a) . By the time apple fruitlets begin to grow past 10 mm in circumference, a good amount of shoot growth has typically occurred. In SE Minnesota orchards, many fruits are between 12-24 mm depending on the location, variety, and other factors; vegetative shoots were around 7 inches long and stil...

Marissa Schuh A hot weekend shifted into a week of wildfire smoke over much of the state. Some areas got some soaking earlier this week, and there is some more rain in a forecast, a relief as much of greater Minnesota is abnormally dry or in D1 drought . Some beautiful early season produce is being harvested and heading to markets and CSA boxes. Wildfire smoke and plant health The effects of wildfire smoke on plants is poorly understood, and what we do understand is that it is complex. For example, while the smoke does block some sunlight, it also creates diffuse light, which can more easily penetrate the plant canopy than direct sunlight. If the smoke is high in ozone, this can damage plants, causing a variety of white and yellowing speckling on a wide range of vegetable crops. The impact of the smoke will also vary depending on how close or far you are from the source , we may see different things in parts of Northern Minnesota where there were local fires, compared to the metro and...

Madeline Wimmer, UMN Extension Educator- Fruit Production & Soon Li Teh, Extension Specialist and Assistant Professor in Grape Breeding and Enology Image: a plant nutritional pyramid showing from bottom to top those nutrients supplied by air and water: Carbon (C), Hydrogen (H), and Oxygen (O); primary macronutrients: Nitrogen (N), Phosphorous (P), and Potassium (K); secondary macronutrients: Calcium (Ca), Magnesium (Mg), and Sulfur (S); micronutrients: Molybdenum (Mo), Boron (B), Nickel (Ni), Copper (Cu), Zinc (Zn), Iron (Fe), Chlorine (Cl), and Manganese (Mn).  Graphic created by Madeline Wimmer, 2023. Plant nutritional analysis—also known as foliar/leaf/petiole testing—is the practice of analyzing nutrition within a plant to determine adequate, excess, or deficient nutrient levels. Oftentimes, this involves collecting a plant’s leaf, leaf with petiole, or only the petiole at a specific growth stage.  Plant nutritional analysis is a critical step in determining any poten...

Marissa Schuh, Horticulture IPM Extension Educator. Originally published in 2023, updated 2025. Flea beetle continues to be one of the biggest pests on Minnesota vegetables farms, especially in our brassica crops. Some of the most effective things we can do to manage this pest happen before we see damage (AKA, the combination of rotation and row covers).  We're past the window where that particular tact can be taken, as applying row covers where flea beetles are already feeding just keeps them close to our crops. Flea beetle damage on mustards. Whitney Cranshaw, Colorado State University, Bugwood.org Quick refresher on some key things that can be done about flea beetle at this point in the growing season. The larger the crops are, the more resistant they are to feeding (though they do often feed on what we are hoping to sell). Solanaceous crops may be getting to the point where flea beetle feeding matters less. Kaolin clay can provide a physical barrier to feeding (but doesn’t alw...

Marissa Schuh, Horticulture Integrated Pest Management extension educator Thinking about scaling up your vegetable production? Curious about irrigation setups, integrating chickens into a vegetable farm, or organic pest management? Want to connect with UMN researchers and extension educators? Sign up now to attend the Organic Fruit and Vegetable Field Day July 15 from 5-8 on the UMN St. Paul campus . Enjoy a free meal, tour university research plots, and network with other growers and resource people from the UMN. This event is free and will be interpreted, please register so we can make sure we have enough food and the right interpreters in place. This event is sponsored by the Midwest Transition to Organic Partnership Program. For more information and registration, visit the event information page  or fill out the below form. Loading… Questions? Reach out to Marissa Schuh at mschuh@umn.edu.