This disease was observed in a home garden recently on table beet (Figure 1). I was surprised considering how dry it has been. Cercospora leaf spot also affects swiss chard. Symptoms include circular leaf spots that may have a reddish margin. The center of the lesions may start off a light brown and turn to gray after the fungus (Cercospora beticola) begins to sporulate.[Read More…]
Question: Why are the water droplets arranged so evenly around the edge of this cucurbit leaf? Answer: The water droplets came out of pores that are at the edge of the leaf where a vein ends. The pores are called hydathodes. The droplets form through the process of guttation. Guttation is when the water pressure[Read More…]
Tomato brown rugose fruit virus (ToBRFV) is making headlines and eliciting USDA action. Growers need to learn more about ToBRFV biology, symptoms and control. Tomato brown rugose fruit virus (ToBRFV) is a newly identified virus affecting tomato, pepper and possibly their relatives. ToBRFV first appeared in Israel in 2014. Since then, it has shown up[Read More…]
In the last issue of the Vegetable Crops Hotline, I wrote an article about common diseases of cantaloupe and watermelon transplants. Based on the samples I have received over the last few days, I would like to write about a disease that is not usually a problem: angular leaf spot. Angular leaf spot affects all[Read More…]
Botrytis gray mold can cause disease on many different host plants, enabling the fungus to easily survive and disperse between crops. Host crops include flowers such as geraniums, vegetables such as green beans and fruit such as strawberries. The disease is favored by relatively cool temperatures and high humidity. We recently observed botrytis gray mold[Read More…]
In creating the new format of the Midwest Vegetable Production Guide for Commercial Growers 2020 (ID-56), I inadvertently left out the portion of the fruiting vegetable section that deals with Phytophthora blight of pepper. The new format allows me to update items easily; I have now added information on this important disease. Go to mwveguide.org[Read More…]
1. What caused the water-soaked stem of this watermelon transplant? A-damping-off B-gummy stem blight C-Lightening strike Correct Answer: B 2. Is this problem likely to spread to other transplants? Yes 3. Will this problem likely spread in the field? Yes More information about gummy stem blight can be found in the article Cantaloupe and Watermelon[Read More…]
Many cantaloupe and watermelon growers are either growing transplants in a greenhouse or are expecting delivery of transplants in the next few weeks. Either way, growers should inspect transplants for disease before planting in the field. Below I will describe several common transplant diseases of cantaloupe and watermelon as well as management options. Gummy stem[Read More…]