These are great ideas that we can try for controlling diseases that sometimes take over our vegetable gardens!
Use mulch – Mulch vegetable plants with most any organic material such as straw, compost or thin layers of grass clippings to a depth of 2-3 inches. Mulch reduces weed seed germination, helps to retain soil moisture, alleviates high soil temperatures, and adds organic matter.
Practice garden sanitation – Some leaf disease can be managed or at least their progress can be slowed by removing infected leaves as soon as the spots appear. To lessen disease spread do not work around plants when leaves are wet. Since many diseases can hang out on old leaves and stems to infect plants next year, remove and destroy infected leaves, stems and unharvested fruit at the end of the season. Bury in an unused part of the garden or start a compost pile specifically for ornamentals and not vegetables.
Use fungicides appropriately – Most fungicides are preventatives so they have to be applied before infection occurs or early when disease first appears. Not all fungicides are labeled for edibles and not all fungicides will control all diseases. One fungicide application rarely helps. Applications are usually needed at 5- to l0-day intervals during humid or wet weather. Be sure to read and follow all label directions especially the days between application and harvest.
For more details, check out our source: University of Illinois Extension