Fruit and Vegetable News

Authors: Marissa Schuh and Natalie Hoidal Just as things get dried out, we get another flush of rain.  There are a lot of plant diseases and insects around, but farms are still sending all kinds of vegetables to market. Read on for updates on fertility, protecting pollinators as crops flower, and organic fungicide recommendations. Weather NOAA has released its outlook for July, and is calling for normal temperatures and above average precipitation. Source: NOAA This likely means disease pressure will continue – many diseases thrive not only in wet conditions, but temperatures in the 70s and 80s are in the ideal range for many pathogens. Plant Disease As disease pressure will continue to be high, it might be time to lean on chemical tools. Fungicides and bactericides are best used preventatively – for pathogens where thresholds are available, the thresholds are often “trace,” meaning that you start treatment as soon as you see any sign of disease. When you see your first leaf spots, o

Madeline Wimmer- UMN Fruit Production Extension Educator This fruit update contains information about… Apples Insect pest updates: leafhoppers and apple maggots. Using hail nets to mitigate hail damage and as an exclusion tactic for managing insect pests (video included). Grapes Disease update: powdery mildew. Insect pest update: Japanese beetles. Minnesota Department of Agriculture IPM Fruit Update sign up form. Apples Insect pest update Leafhoppers Images: 1) A collection of shoots tips on an apple tree showing curled leaves, 2) a close up of a shoot tip with curled leaves, and 3) the underside of a curled leaf revealing a leafhopper insect (family Cicadellidae). Unlike some other foliar symptoms, apple leaf curling can be easily spotted in an orchard. After turning a few leaves over, the culprit pest can usually be found on a leaf’s underside. While insect pests like aphids and mites can cause leaf curling in apples, leafhoppers can also lead to leaf curling.  Leafhoppers are insect

Bill Hutchison, Suzanne Wold-Burkness, and Erin Buchholz* *UMN Landscape Arboretum Japanese beetle emergence – as indicated by beetles on wine grapes, or those captured in pheromone traps – is now underway in the Twin Cities metro, and perhaps other areas of southeast and southcentral Minnesota. For those who have experienced high infestation levels on farms, backyard gardens or roses, you are fully aware of the feeding damage that can occur. As part of our research on Japanese beetle (JB) population trends the past 4 years, we continue to see some good news with a biocontrol option for the pest. The Winsome Fly (WF, Istocheta aldrichi ) is currently one of the most noticeable and notable JB biocontrol agents in Minnesota. WF eggs on mating pair at vineyard, near Montreal, Quebec (credit: Jacques Lasnier.) Usually only 1 or 2 WF eggs are laid per JB; however, when host density is low, higher egg-lay can occur. We have now documented WF parasitism rates of 10-50%. WF has the potential

Annalisa Hultberg, Extension Educator, food safety With this very wet summer, some farms in Minnesota have seen significant flooding damage. Flooding can be detrimental to crops for a number of reasons, including potentially introducing chemical and microbial risks to the fresh produce that can then cause human illness if ingested.  Here are some guidelines to keep in mind when you are considering the safety of your produce after a flooding event.    Image courtesy of Produce Safety Alliance and Keith McCall,  of the National Resource Conservation Service Food Safety Risks with Flooding First, remember that according to the FDA, floodwater is defined as the water that has come onto your property from a source off the property. It is not just heavy rain falling and pooling around your plants, or a sprinkler left on overnight.  The risks from flood waters that come in two main categories:  human microbiological pathogens such as bacteria, viruses and parasites that can cause foodborne il