Fruit and Vegetable News

 Author: Natalie Hoidal, Extension Educator, Local Foods and Vegetable Production At this point in the season, at least for diversified vegetable farms, the busiest part of the season is behind us. There’s still a lot of work to be done, but I encourage you all to take some time to make a plan for fall Brassica management, and in particular disease prevention. This season has been generally dry with fewer disease problems than normal, but we’re starting to see pressure from black rot (Xanthomonas campestris pv. campestris) and Alternaria leaf spot (Alternaria spp.) What can you do at this point in the season to prevent problems?   Late summer Brassicas are often a source of inoculum for fall Brassicas. Photo: NH What can you spray? I reviewed twelve recent trials assessing the impact of various fungicides on black rot and Alternaria leaf spot in Brassicas, and compiled the results of each product into a table for comparison (see below). The data is complicated. A few of the co...

Black rot on cabbage. M.Grabowski, UMN Extension Project Overview In the summer of 2018, Meg Gable, a UMN Agriculture/Food Business Management student with guidance from Michelle Grabowski, UMN Extension Professor, set out to learn more about how to best manage black rot of cabbage. The goal of the project was to compare susceptible and resistant varieties of cabbage and to determine if removing infected leaves would stop the spread of a black rot infection. Veins turn black as the black rot bacteria moves through the leaf.  M. Grabowski, UMN Extension Overview of Black Rot  Black rot is a common disease of crops such as cabbage, cauliflower, broccoli and other brassicas. It is a bacterial infection that moves through the veins of plants, travels to the stem and affects brassica plants in many ways depending on variety and time of infection. Cabbage is a labor-intensive crop and if infected, black rot can spread easily and destroy an entire crop. However, th...

There are many things to consider when choosing what seed varieties to purchase and where to buy seed from. Which varieties grow well in the environmental conditions on your farm? Which varieties will sell best in your market and which will draw in new customers? It is equally important to consider how the seed you purchase will affect the health of your crop. That great looking variety of squash is not going to sell well if the fruit are covered in soft, rotten spots. Choice of seed can affect future disease problems on your farm in several different ways. Plant Disease Resistant Varieties Each seed company uses its own code to indicate which diseases a variety is resistant to. Look for a key to find resistance to a specific disease. M. Grabowski, UMN Extension  Choosing disease resistant varieties can stop disease before it starts, improving your yield and reducing the time and money spent on managing disease problems. Due to their specific genetic makeup, ...

As the season wraps up and tools and equipment are stored away for the season be sure to clean tools properly to prevent plant pathogens from surviving from one season to the next. Soil covered tools, ready to be cleaned and disinfected M. Grabowski, UMN Extension Plant pathogens have multiple strategies for survival. Many common plant pathogens survive in infected plant debris and soil. As a result, crop rotation and proper disposal of crop residue play an important role in reducing disease problems from year to year. But what about the large equipment, hand tools, wires, stakes, high tunnel plastic, clips, and other day to day objects that are used throughout the production season? Can plant pathogens survive on tools and equipment?  Some viruses like Tomato Mosaic Virus, Tobacco Mosaic Virus, and Pepper Mild Mottle Virus are very durable and can survive on the surface of tools, greenhouse plastic, pots, and other equipment that comes in contact with infected plants. Fu...