Plant Diseases Management

To no one’s surprise this week has seen a great number of problems pop-up in tomato fields throughout our area. The first of course has been disease with bacterial and fungal diseases spreading. The fungal pathogens usually can be contained with timely (as difficult as that is) fungicide applications. Bacterial spot or speck on the other hand can be much more difficult to control once it gets started and the weather remains wet and warm. In figure 1 on the right hand side is a row of tomatoes that had been sprayed with fungicides and copper for the last several weeks. Bacterial spot has ravaged this row.

Using Silicon, Stimplex and Plant Resistance in Pumpkin Production Systems to Reduce Plant Disease Loss

Severe outbreaks of downy mildew in garden impatiens (Impatiens walleriana) were reported first reported in the fall of 2011 on landscape plantings in Europe as well as in the US (Northeast, Midwest). In Maryland, the Plant Diagnostic Lab received its first infected sample in early June 2012. If you grow garden impatiens, it is important to be on the lookout for this disease.

I recently received an inquiry from a high tunnel grower about unusual symptoms on tomato leaves.

Fruit and Vegetable News, Volume 12, Issue 3 (June 10, 2021)

Managing gray mold (Botrytis) on strawberries is increasingly challenging because of fungicide resistance development, plus a new Botrytis species that is less susceptible to fungicides is becoming common in the mid-Atlantic region. Resistance to certain fungicides is also a problem in management of anthracnose fruit rot. This article describes disease management strategies designed to slow further resistance development, while also providing specifics for managing our two most common fruit rots. Authors: Dr. Mengjun Hu, Univ. of Maryland, and Kathy Demchak, Penn State Extension

Troubleshooting disease symptoms in wheat.

Take a look at the research happening here at the Central Maryland Research and Education Center in Upper Marlboro (CMREC-UM). Even though we are one of the smallest Research and Education Centers (RECs) in the State, our scope of research is quite vast.  Here at CMREC-UM you will find research on agronomy, cover crops, forestry, horticulture, irrigation, livestock, water quality and more.

As you’re scouting fields this summer, keep this fungal disease in the back of your mind. Tar spot is a fungal disease of corn caused by Phyllachora maydis. It was first discovered in the United States in 2015. In Latin America where tar spot is more common, another fungal species, Monographella maydis, is known to occur in complex with P. maydis; however, only P. maydis has been found in the United States.

With corn harvest underway across the state, growers may be encountering ear rots and stalk rots in affected fields. The degree of severity is dependent on a variety of factors, so it is wise to scout fields prior to harvesting in order to identify problematic fields and give those harvest priority.