Dr. Elizabeth Little, a plant pathologist with UGA, was also there, and her talk was very different. She said some things I've been trying to tell people for years, but she said it all better and with the authority of a PhD who has been doing actual, official research into the topic. The gist of it was this:
There are no organic products that REALLY work for disease management; switching to organic farming or gardening isn't about simple substitutions of one chemical for another. Essentially, in organic operations, it's all about prevention.She emphasized that healthy plants resist disease, and that we can promote good root growth and beneficial microflora (and by doing so improve plant health) through providing compost and other organic amendments, by mulching, by reducing the amount of tillage, and by using cover crops.
The organic farmer/gardener takes a systems approach to plant health - based on fertility, plant selection, crop rotation, sanitation, and site selection. The organic system also relies a lot on biological interference with disease; by promoting a good ecological system in the soil (a wide range of fungi, bacteria, and creepy-crawlies), the organic gardener/farmer heads off many potential problems.
Any problems that crop up typically indicate an underlying health issue.
Encouraging predator insects, parasitoids, and microbes as allies was also brought up. Relying on an ecological approach of planting flowers that are attractive to these beneficial organisms was part of the biological approach of disease prevention. Some diseases are in the wind and can't really be intercepted or diverted, but others are spread through the feeding of insects, kind of like the way mosquitoes spread disease from one animal to another. The "beneficials" help by attacking the disease-spreading insects.
When I spoke with Dr. Little later in the day, when we were touring the campus farm, she emphasized the "right plant in the right place" approach to plant health in a great example: She said that she had seen lone tomato plants out in the full sun, with good mulch around them, well-fertilized and mulched, and they were completely unblemished - no signs of disease anywhere - when other tomato plants in the area were definitely ailing.
It was great that she chose Tomato as her example, because that seems to be the garden vegetable that is most affected by disease, in a way that causes the most distress to the gardener, in Georgia. Usually, when someone asks me about disease in the garden, we end up talking about tomatoes.
I left the workshop feeling extra-motivated to keep emphasizing the importance of all the little steps - using compost, paying attention to plant varieties and their disease resistance, making sure there is adequate sunlight for the plant, and using mulches and cover crops.
All in all, it was a great day.