Fruit and Vegetable News

Authors: Natalie Hoidal & Marissa Schuh This week has brought some needed relief from drought, heat, and wildfire smoke. Temperatures have dropped dramatically and conditions have been excellent for field work, allowing farmers to catch up on weeding and all of the other tasks that got delayed due to weather in July. We are officially transitioning into fall planning mode: planning for the shift towards more disease pressure that comes with cool nights, planning for fall planting, and wildlife pests becoming more of a problem as harvest for crops like melons and sweet corn arrives. Scout and prep for an uptick in diseases We finally have weather that is pleasant to experience. The catch of the cool morning is an uptick in dew on plants – which can provide the wet conditions fungal diseases need to get established, as well as the water needed for bacterial diseases to move around. Continue to scout weekly – when scouting, make sure you check the oldest leaves and the densest parts ...

Author: Natalie Hoidal, Reviewed by: Cindy Tong & Charlie Rohwer Melons are one of the trickiest plants to grow, because the guidelines around harvest are confusing and often contradictory. I often hear growers express frustration because their melons seem ripe but don’t have much flavor, or because they spoil faster than they should. This article presents an overview of ripening, as well as harvest and storage tips for melons, watermelons, squash, and pumpkins. Some ripening basics Fruit and vegetables are typically assigned to two categories that define their ripening behaviors: Climacteric: Climacteric fruits and vegetables continue to ripen off the vine. They experience a rapid increase in respiration during ripening. They also often produce a hormone called ethylene after harvest, which can speed up ripening and senescence. If eaten at an immature stage, these fruits and vegetables taste bland, and the texture is often not as soft as it is meant to be. If left at room tempera...

  Article written by Madeline Wimmer, UMN Extension Fruit Production Educator. Apples Article: Red star rust: Scout for a new apple disease More on cedar-apple rust  Day-neutral strawberries Harvest season ramping up in southern Minnesota Management: Runner removal Fruit diagnostics: Misshapen fruit  Article: Tarnished plant bug in strawberries: Pollinator-friendly management considerations Apples Article: Red star rust: Scout For a New Apple Disease Images: Crabapple leaves with red star rust from left to right: Top: ‘Cashmere,’ ‘Dolgo,’ Firebird®; Bottom: Marilee®, ‘Prairifire,’ and ‘Purple Prince.’ The color of red star rust spots differs by cultivar. Cultivars with white flowers often have yellow spots. Cultivars with dark pink or red flowers usually have red spots. Many growers are familiar with cedar-apple rust ( Gymnosporangium juniperi-virginianae ), which can impact apple leaves and fruit when infection pressure is high. There are a number of fungal pathogens in ...

Article written by Tiffany Enzenbacher, Researcher, enzen010@umn.edu ; Dr. Matt Clark, Associate Professor; and Dr. Brandon Miller, Assistant Professor August is the time to scout apple and crabapple trees for red star rust. Red star rust is caused by the fungal pathogen Gymnosporangium yamadae .  Red star rust was recently detected in Minnesota in 2022 and has since been reported in 11 counties surrounding the Twin Cities metro, including Anoka, Carver, Dakota, Goodhue, Hennepin, Le Sueur, McCleod, Ramsey, Rice, Scott, and Washington Counties.  This disease is unique in that it affects two unrelated types of plants – apple ( Malus spp.) and juniper ( Juniperus spp.). Both plants are needed for completion of the red star rust life cycle.  Apple and crabapple Red star rust causes large spots or blotches on the upper leaf surface that are readily observed in mid to late summer. Brightly colored spots are typically irregular in shape with red borders. Bristly fungal projec...