A cheap and easy way to reduce disease loss is to plant disease-resistant varieties. Many vegetable varieties are available with resistance to one or more diseases. For instance, tomato varieties resistant to Fusarium wilt and Verticillium wilt are available for home gardens and are the primary methods of reducing losses to these diseases. Pea varieties are available that are resistant to powdery mildew. No variety is resistant to all diseases.
Some catalogs list resistance information clearly.
Inspect transplants for disease. Planting diseased vegetable seedlings is a quick way to run into trouble. Inspect transplants carefully, and buy only vigorous-looking seedlings. Check the leaves for spots, distorted shape or any unusual yellowing or browning. Also examine stems and roots, if possible, for any symptoms of discoloration or rot.