Fruit and Vegetable News

Posts

Spotty tomato leaves - what is it and what to do

Marissa Schuh, IPM Extension Educator, mschuh@ umn.edu . Originally published 2025, revised 2026. 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 Common leaf spot disease caused by fungi 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 ...

Testing water on your farm for food safety - follow this script to "speak lab"

Annalisa Hultberg, Extension Educator, Food Safety If you use well or surface water in the production of your fresh fruits and vegetables, bacteria, viruses or parasites may be present in water and contaminate your produce or equipment. You might assume your well water is safe because it smells and tastes good, but without testing it, you cannot tell if the well is failing or surface water is getting in. But what do you tell the water testing lab when you call? Follow this general script to help navigate that conversation. What to test for? You will want to test your well and surface water sources for generic E. coli, since this is an indicator of the presence of fecal contamination in your water. Where there is E. coli, there might be poop, and where there might be poop, there might be a host of other pathogens such as Salmonella , Cyclospora, or Listeria monocytogenes . You might add things like lead, arsenic or nitr...

Produce Growers: Summary of how to talk with your customers about Cyclospora

Annalisa Hultberg, Extension Educator, food safety This short article is intended to help fruit and vegetable farmers quickly understand how to talk with their customers about the current Cyclospora outbreak and to dispel misinformation. What you need to know about the parasite as a farmer Cyclospora is a microscopic protozoan parasite that can cause severe, watery diarrhea among other symptoms when ingested. It comes from feces from infected humans, not animals or wildlife. Cyclospora can contaminate fresh produce when water that is used on the farm during growing (most often from sources like rivers and streams) contains human feces from a person who is ill with the parasite. It can be very difficult or impossible to wash the parasite off produce once it gets on. The source of the current outbreak is likely contaminated surface water used for irrigation, but the investigation is ongoing. Well water is much less likely to be contaminated with fecal material. Produc...

Cyclospora outbreak tracking and reducing your risks as a fruit and vegetable grower

Annalisa Hultberg, Extension educator, food safety Note: Since this is an evolving investigation, updates will be posted as they are available. The original article with more details is below the updates. Update 7/20: On 7/19, after reviewing the results from recent sampling efforts, the FDA announced that the previously confirmed positive test of Cyclospora linked to the current 5-state outbreak from Taylor Farms was a false positive. While there are not currently any documented positive tests, this does not mean that the produce causing illnesses definitely did not come from Taylor Farms in central Mexico. It just means that a positive test confirmation is not present. The epidemiological studies that are following ill consumers continue to indicate that Taylor Farms lettuce from central Mexico is the likely source of the illness, though the case is evolving as more information comes in. Taylor Farms de Mexico is recalling iceberg lettuce sourced from centr...

Managing wildfire smoke: impacts to crops and workers

Author: Natalie Hoidal . Originally published 2021, updated 2026. Over the past few days, much of Minnesota has been blanketed by unhealthy concentrations of wildfire smoke from fires burning in Canada and northern Minnesota. How does the smoke impact you, and how does it impact your crops? First, it's worth acknowledging that wildfires have gotten worse in the US over the past few decades, which is attributed to historical forest management strategies and climate change. Impacts to plant health When the sky is thick with smoke, it’s hard to imagine that there’s not an impact to crops. However, the impacts are a bit nuanced. Access to light Wildfire smoke aerosols do create a shadier atmosphere, so you’d think that sunlight isn’t reaching plants as well. However, studies like Hemes et al. (2020) have found that wildfire smoke creates more diffuse radiation (aka light is scattered throughout the atmosphere), and plants can use this light more efficiently than direct so...

Weekly Vegetable Update July 16, 2026

Authors: Natalie Hoidal & Marissa Schuh This is one of the busiest weeks of the summer and it’s hard to take breaks or slow down, but working in this heat and smoke is dangerous, both for your immediate and long term health. Take good care of yourselves and your people. What does it mean to work safely in this heat (and now smoke)? Farm workers are among the most at risk people for heat related deaths, and the numbers are likely under reported. The risks are exacerbated by smoke. We realize we’ve talked about heat a lot in this newsletter this summer, but that’s the reality we’re living with. We also realize telling farmers not to work is unrealistic, as there’s so much that needs to happen on the farm this time of year. So, let’s quickly break down the heat safety guidelines for the conditions we’re experiencing right now. Keep in mind that the following guidelines are for healthy people without underlying conditions. If you have asthma, diabetes, or other conditions that make y...

Fruit Update - July 15, 2026

Article written by Madeline Wimmer, UMN Extension Fruit Production Educator. Heat advisory for Minnesota growers Apples Identifying codling moth damage: Deep entry When should trunk guards be removed from apple trees? Check trellis wires, clips, and bands during the growing season (high density) Grapes Insect gall identification Kiwiberries Article: Kiwiberry production in Minnesota: What's the potential? Heat advisory for Minnesota growers It’s a hot week in many parts of the state. Try your best to stay cool, work during the coolest parts of the day, take breaks, and know how to recognize signs of heat exhaustion for yourself and other workers. To learn more about protecting yourself and others from extreme heat and air quality issues, visit our UMN Extension web page: Develop a heat and air quality safety plan for your farm workers. Identifying codling moth damage: Deep entry Images: An Gravenstein apple showing signs of damage classic to codling moth (...