For starters, we are still in a drought. I know it has been raining, but we still have dry soils. We need the rainfall, but this can cause some disease issues with our vegetable gardening efforts. This current weather of wet and warm temperatures is a good environment for some disease issues such as root rot, leaf spots and fruit rots. Fungi, bacteria, nematodes and viruses are four types of organisms that can cause plant diseases. Sometimes these organisms can be called disease pathogens. I will be sharing information from a UGA publication that was revised by Elizabeth Little, UGA Home Garden/Small Farm Plant Pathologist.
Right now, I would say we are going to be more concerned with fungi and bacteria issue in our gardens due to the current weather pattern. Those pathogens can be more associated with rain and/or heavy dews are present with warm temperatures. Viral diseases can be transferred by insects moving from plant to plant in the growing season also. Nematodes can be associated with lower yields of produce and slower plant growth. Nematodes like warm weather, but they can cause root damage at any time. One way you can cut down on your disease issues is to use good management procedures in your gardening efforts. I know we are in our current gardening season so many of these tips should be filed for future reference.
Proper site is an important key to disease management. The area needs to drain well. Plants are not going to perform well in wet areas that drain poorly. Areas that stay wet will have higher occurrence of seedling diseases plus root and crown diseases. The planting needs to be in a sunny and open area. A sun providing spot will help plant foliage dry easier after periods of rainfall. Planting gardens in more shady areas can lead to humidity that can put disease on the increase.
Crop rotation can also help in reducing disease in the garden spot. Pathogen building can occur if you grow the same vegetable or family of vegetables in the same spot year after year. It is suggested to only grow the same type of vegetable or related vegetables in the same soil once every 3-5 years. Crop rotation can help reduce or starve out many pathogens that can lead to leaf and steam diseases. Little states that in the case of soil-borne problems, you may have to use even longer crop rotations and even other management steps to slow the problems down.
Take advantage of disease free seed and transplants plus disease-resistant varieties. Keep in mind that many plant diseases are seed-borne. Do your homework with seed saving guides on which seed species or cultivars are appropriate to keep. Also, note that Little suggests to only save seed of healthy plants or purchased from seed companies with a good reputation. Some diseases can contaminate the seed of their host plant. When this seed is planted, the new plant has a higher chance of infection from this source of disease. Some of your commercial seed can come from parts of the country where seed-borne diseases are less active. Some clients may buy seed from companies where fungicides have been applied to the seed. This will help protect the seed and the new seedling as it breaks ground, but will not protect the new plant after the seedling stage.
Planting resistant varieties is a good way to battle vegetable diseases. Keep in mind that the term resistance is a loose term. Some varieties may be totally immune or either partially resistant. The resistance is determined by the variety and the type of disease in question.
In some situations, planting date management can help in reducing disease pressure. Planting at the wrong time when soil temperatures are not proper can lead to seed and seedling diseases. This can happen when we plant too early in the growing season and soil temperatures are too cool.
Other tips to consider is proper spacing when planting and even trellising when needed to cut down on disease. Mulch in the vegetable garden can be a helpful tool to cut down on some of the soil-borne diseases. Mulch can cut down on soil splash and can keep growing plant fruit from touching soil.
Also remember that proper irrigation can lead to a healthy plant. Drip irrigation is better since it can keep foliage dry as compared to sprinklers. For more information, contact UGA Extension- Gordon County at 706-629-8685 or email firstname.lastname@example.org.