By Grant McCarty
Local Foods and Small Farms Educator, University of Illinois Extension
For those who garden, the last thing you want to see occur is disease. You’ve spent a considerable amount of time starting your seeds, enhancing your soil, and taking care of your plants to then have disease move in and destroy the plants can be devastating. There are some steps that you can take before, during, and after your season to hopefully prevent disease from occurring this season and the next.
Before I discuss prevention, you need to understand what fruit/vegetable plant diseases are. Diseases are caused by mainly bacterial or fungal pathogens. Each disease has a pathogen that causes it. For instance, Late Blight, a serious disease on tomatoes, potatoes, and others, is caused by Phytophthora infestans.
For disease to occur, the pathogen, a host/plant, and environmental conditions must all be present. Seasonal conditions also dictate pathogen levels. Each pathogen favors certain conditions such as cold, hot, dry, and/or wet weather. Pathogens have many ways of moving into the garden. Water, air, soil, in the mouths of insects, and combinations of these channels are how pathogens move.
Disease prevention practices includes crop rotation, cleaning tools, avoiding wet conditions, watering plants during the day, using disease resistant varieties, among other methods. Crop rotation is an easy strategy that can keep soilborne pathogens from attacking the plants if you rotate out of a different family season to season.
You should remove any dried soil on your garden tools before using them this season as pathogens may be present in the dried soil. This includes tomato cages. If there has been significant rain and your plants are wet, you should avoid working with them as you may be moving pathogens with the tools you use.
Watering your plants in the morning is recommended as it allows for wet leaf foliage to dry out. If you water in early evening, the wet foliage sits in the dark and is more likely to spread disease. If you have yearly problems with disease, there are disease resistant varieties of vegetables available.
As much as you can put these practices into action, they cannot always prevent disease completely. There are environmental conditions that are out of our control. Still, these practices can set you down the right path for disease prevention and a successful harvest.