Proper sanitation measures can keep spores from infecting the next crop. Crop rotation is another means of reducing disease in tomato plantings. Each year, plant your tomatoes in a new location away from areas where tomatoes, eggplant, potatoes, or peppers have grown. These vegetables all have similar disease problems. A minimum rotation of three years is essential to help reduce populations of soil-borne fungi. Please remember that when collecting diseased leaf samples for identification, keep them in a sealed plastic bag to prevent the disease from spreading. Tomato pests can be just as destructive as diseases. Damage to plants from insects, animals, or harsh environmental conditions can create openings for pathogens to enter the plant and cause disease. Aphids ( Aphis spp.) are common visitors to vegetable gardens. Aphids infest a wide range of plants. Some important cultivated hosts include potato, tomato, eggplant, sunflower, pepper, pea, bean, corn, sweet potato, squash, pumpkin, and asparagus. These soft- bodied, pear-shaped insects may be solid pink, green, pink mottled, or light green with a dark stripe. Usually wingless, they are about one-eighth inch long. Aphids pierce veins, stems, growing tips, and blossoms with needlelike mouthparts. As a result, flowers are shed, plants are weakened, and yield is reduced. Aphids can spread rapidly, transmitting viral diseases.
EXAMPLE OF EARLY BLIGHT
What does all this mean? Many of these diseases look similar and can be challenging to tell apart. If you stop at the Penn State Extension office or a garden store for answers, you can describe what is visible on your plants. These descriptions help you see what is happening in your garden. Now that you have caught your breath, let me give you a few more to consider. Late blight is a potentially severe disease of potatoes and tomatoes caused by the fungus Phytophthora infestans . Late blight is especially damaging during cool, wet weather. The fungus can affect all plant parts. Young leaf lesions are small and appear as dark, water-soaked spots. These leaf spots will quickly enlarge, and a white mold will appear along the margins of the affected area on the lower leaf surface. Complete defoliation, browning, and shriveling of leaves and stems) can occur within fourteen days of the first symptoms. There are products effective against these three diseases. Products containing chlorothalonil or mancozeb are the most effective. Several cultural practices help reduce tomato disease. The first cultural practice is to remove old plant debris. Overwintered fungal spores are splashed from infested tomato or weed debris in the soil onto newly planted tomatoes. This restarts the disease cycle. Also, space plants so they do not touch each other, mulch plants, and fertilize properly.
HORNWORM CATERPILLAR
Hornworm caterpillars feed primarily on solanaceous plants, those in the potato family. They include tobacco, tomato, eggplant, pepper, and some weeds. Tobacco and tomato plants are preferred. Hornworms are probably the easiest insect to identify. Hornworm eggs are smooth, spherical, and one-sixteenth inch
23
July–September • 2026
Powered by FlippingBook