Leaf and Whole Plant Problems

Seedlings foil over; stems girdled or rotted at soil line. Cause: Damping-off. Disinfect reused pots and flats by dipping them in a 10 percent bleach solution and letting them air-dry before filling them with fresh seed-starting mix. Sow seeds thinly to allow for air movement around seedlings. Cover seed with a thin layer of soilless mix or vermiculite. Water only enough to keep soil moist, not soggy. Thin seedlings and spray with compost tea as soon as First true leaves open to help prevent the problem.

Seedlings clipped off at soil line. Cause: Cutworms. Check for fat, l"-2"long, dull brown or gray caterpillars in the soil near the base of plants. Once they chew off a seedling, there is nothing you can do except protect the remaining seedlings from nocturnal cutworm attacks. Place cutworm collars around transplants, sprinkle moist bran mixed with BTK on the soil surface in the evening, or add parasitic nematodes to the soil at least a week before planting to control them.

Leaves pale green and small. Cause: Nitrogen deficiency. Spray plants and drench roots with fish emulsion to alleviate symptoms, and side-dress with compost.

Leaves yellow, distorted, and sticky. Cause: Aphids. These small green, pink, black, gray, or white fluffy-coated insects suck plant sap. For mild infestations, knock pests off plants with a blast of water. Spray plants with insecticidal soap in the evening to control, or with a commercial neem or pyrethrin spray if infestation is severe.

Leaves mottled with yellow; young growth malformed. Causes: Tobacco mosaic virus: other viral diseases. Destroy diseased plants. Presoak seed in a 10 percent bleach solution before planting, or choose resistant cultivars to prevent problems. Wash hands after handling tobacco and before touching peppers to prevent tobacco mosaic virus (TMV). Control aphids. because they spread viral diseases as they feed. Prevent problems by planting resistant cultivars such as 'Ace', 'Bell Captain, 'Bell Tower', 'Early Wonder'. 'Elisa'. 'Galaxy', 'Goldcrest', "Gypsy', 'Lady Bell', 'Lasto', 'Northstar'. Orobelle', and 'Yolo Wonder'.

Leaves yellow; plant stunted and wilts in hot weather. Cause: Nematodes. Plants eventually die. Roots may have swollen galls. Destroy infested plants, do not compost them. To control these pests, apply chitin or parasitic nematodes to the soil.

Older leaves yellow; shoots or whole plant wilts. Cause: Fusarium or Verticillium wilt. Fusarium wilt and Verticillium wilt are both fungal diseases and are difficult to tell apart. Both Fusarium and Verticillium wilt begin as a yellowing and wilting of the lower leaves.

Plants are stunted and do not recover when watered. Cut open a stem near the soil line and look for internal discoloration. Verticillium fungi are active between 68° and 75°E while Fusarium is active between 80° and 90°F Destroy infected plants. Pepper Fusarium infects only peppers, while Verticillium infects a wide range of plant species, making effective rotation control difficult. Prevent problems by presoaking seed in a 10 percent bleach solution. Control pest nematodes to help reduce wilt problems. Few wilt-resistant cultivars are available; 'Giant Szegedi' is tolerant of Verticillium.

Leaves stippled yellow, or bronzed. Cause: Mites. Leaves turn dry and papery. These tiny, spiderlike insects thrive in hot, dry weather. Spray plants with insecticidal soap if populations are high (more than 1-2 pests per leaf).

Leaves with small, sunken, yellow-green spots. Cause: Bacterial spot. Spots eventually turn brown with lighter centers. Spray plants with copper as soon as symptoms appear to prevent further symptom development. Presoak seed in a 10 percent bleach solution to disinfect, and avoid touching wet plants.

Leaves with gray-brown spots. Cause: Cercospora leaf spot. This fungal disease only occurs in very warm climates. Spots develop a "frog-eye" appearance with light centers and dark edges. Spray planLs with copper as soon as symptoms appear to prevent further symptom development. Presoak seed in a 10 percent bleach solution and plant resistant cultivars, such as 'California Wonder", to prevent problems.

Leaves with wandering, white or translucent tunnels. Cause: Leafminers. White, maggotlike larvae feed inside leaves, leaving empty tunnels behind them. Once larvae have entered leaves, spraying will not control them. Destroy mined leaves. Cover plants with row cover until flowers open to prevent adults from laying eggs on plants. Certain nematodes can attack leafminer larvae inside leaf tunnels.

Leaves with small holes. Cause: Flea beetles. Young transplants are the most susceptible. These tiny, black, brown, or bronze insects hop when disturbed. Spray or dust plants with pyrethrin if infestation is severe. Protect transplants with row cover until they start to flower.

Leaves with large holes. Causes: Horn-worms; other caterpillars. Hornworms are 3"-4'/2" caterpillars with white diagonal stripes. The tobacco hornworm has a red horn projecting from the rear, while the tomato horn-worm has a black horn. Handpick or spray plants with BTK to control them. Do not spray caterpillars that are covered with small white cocoons; these cases contain the larvae of parasitic wasps that are natural hornworm predators.

Other caterpillars such as European corn borers and corn earworms sometimes feed on pepper leaves and fruit. Handpick, or spray plants with BTK if many caterpillars are feeding.

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