Seeds do not germinate; seedlings stunted or dying. Causes: Seedcorn maggots; damping-off; root rot. Seedcorn maggots are W long, yellow-white, spindle-shaped seed-eaters. Adults are small flies. Seedlings that do come up are deformed and spindly. Remove damaged seedlings and plant fresh seed about a week after applying parasitic nematodes to the soil to control maggots. Seedcorn maggots thrive in cool, wet soil, so wait until soil is warm to plant to help avoid problems with them.
Damping-off is caused by soil-dwelling fungi that thrive in cool, wet conditions. Keep soil moist, but not soggy, thin seedlings to improve air circulation, and spray them with compost tea as soon as the first true leaves open to prevent problems.
Pea root rot can kill seedlings. Older infected plants are stunted and have shrunken, discolored roots and stems near the soil line. Prevent problems by planting in well-drained soil with lots of organic matter. Beans are susceptible to the same fungus, so keep the 2 crops apart. Prevent problems by planting cultivars, such as 'Bolero' and 'Sprite', that are somewhat tolerant to pea root rot.
Seedlings clipped off at soil line. Cause: Cutworms. Check for fat. 1 "-2" long, dull brown or gray caterpillars in the soil near the base of plants. Sprinkle moist bran mixed with BTK on the soil surface in the evening, or apply parasitic nematodes to the soil at least a week before planting to control them.
Leaves yellow; growth slow. Causes:
Nitrogen deficiency; waterlogged soil. Drench soil and spray foliage with compost tea, fish emulsion, or fish-meal tea, or side-dress plants with compost to alleviate deficiency symptoms. Waterlogged soil damages roots and prevents them from using nutrients available in the soil. Prevent problems by choosing well-drained sites, adding organic matter to the soil to improve drainage, and planting in raised beds.
Leaves yellow and distorted. Causes: Tarnished plant bugs; pea aphids; potato leaf-hoppers. Tarnished plant bugs are oval, light green or brown, V*" long bugs that inject a plant-deforming toxin as they feed on young leaves. Trap them with white sticky traps or treat plants with a commercial pyrethrin spray or dust in the evening to control severe infestations.
Pea aphids are soft-bodied, small, light to dark green, sucking insects usually found on new growth. Infested leaves are thickened and curled and may be covered with a sticky material. For light 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. Repel aphids with reflective mulch or by planting cultivars with silvery leaves.
Potato leafhoppers are green or brown, spindle-shaped, Vio'-'A" long, winged insects. Nymphs are smaller and wingless. Infested leaves have curled margins, and flowers or pods may fall off. Trap leafhoppers with yellow sticky traps or spray as for pea aphids above. Cover seedlings with row cover if leafhoppers have been a problem in the past.
Leaves yellow; plant wilting and stunted. Cause: Fusarium wilt. Stem near soil line is yellow-orange to black when cut open. If pods form, they contain few seeds. Destroy plants infected with this fungal disease. To prevent problems, plant resistant cultivars such as 'Bounty', 'Daybreak', 'Green Arrow', 'Knight',
'Maestro', 'Oregon Sugar Pod 2', 'Snowflake', and 'Sparkle'.
Leaves mottled and distorted. Cause: Mosaic viruses. Destroy infected plants. Control aphids and cucumber beetles that spread viruses, and leguminous weeds, such as vetch, that can harbor viruses. Prevent problems by planting tolerant cultivars such as 'Knight1 and 'Maestro'.
Leaves stippled with white. Cause: Mites. Leaves become bronzed when severely infested. These tiny, spiderlike insects thrive in hot, dry weather. Look for tiny moving specks on the undersides of leaves. Spray plants with insecticidal soap in the evening to control mites.
Leaves with water-soaked or white spots. Causes: Downy mildew; powdery mildew. Downy mildew is common in damp weather. Leaves and pods are covered with a thick, white growth that turns violet-black. Powdery mildew is more common in dry weather. The whole plant may be covered with white powdery growth. Spray plants with sulfur in the evening, as soon as you notice either disease. Prevent problems by planting cultivars resistant to downy mildew, such as 'Green Arrow' and 'Knight', or to powdery mildew, such as 'Bounty', 'Knight', 'Maestro', 'Oregon Sugar Pod 2', and 'Snowflake'.
Leaves with light brown to purple spots. Cause: Blight. Stems and pods are also spotted. Leaves may turn yellow and plants may die. Various fungi and bacteria can cause these disease symptoms. Spray plants with copper if weather is wet. Remove severely infected plants. Presoak seed in compost tea and don't touch plants when they are wet to help prevent problems.
Leaves with wandering, white or translucent tunnels. Cause: Leaf miners. Larvae are white maggots that tunnel through leaves. Adults are tiny black-and-yellow insects. Once tunnels appear, the larvae are inside leaves and spraying will not kill them. Destroy infested leaves. Trap future generations of adults with yellow sticky traps, and treat plants with a commercial neem or pyrethrin spray if large numbers of adults are trapped. Prevent problems by protecting plants with row cover as soon as they come up to exclude egg-laying adults. Certain parasitic nematodes can attack leafminer larvae inside leaf tunnels.
Leaves with small holes. Cause: Cucumber beetles. Damage usually occurs on young plants. Beetles are yellow or greenish, '/«"long, with spots or stripes. Treat plants with a commercial pyrethrin spray or dust if infestation is severe. Cover emerging seedlings with row cover to prevent problems.
Leaves with large holes. Cause: Caterpillars. Many caterpillars feed on leaves and pods. Handpick, or spray plants with BTK if worms are feeding.
Blossoms drop; no pods form. Causes: Weather extremes; nutrient imbalances. Excessive heat or rain can cause blossoms to drop. Wait for new blossoms to form. Copper and/or molybdenum deficiency cause the same symptoms. Spray plants with seaweed extract to help prevent deficiencies. If plants are very dark green and no blossoms form, suspect too much nitrogen. Wait for blossoms to form. Avoid high-nitrogen fertilizers.
Young pods distorted and withered; older pods with water-soaked or purplish spots. Cause: Blight. See "Leaves with light brown to purple spots " above for controls.
Pods mottled, deformed, and rough. Cause: Mosaic viruses. See "Leaves mottled and distorted" above for controls.
Pods with white spots. Causes: Downy mildew; powdery mildew. See "Leaves with water-soaked or white spots" above for controls.
Pods with chewed holes. Cause: Caterpillars. Various caterpillars eat pea pods. Handpick, or spray plants with BTK if cater pillars are feeding. Cover young plants with row cover to prevent moths from laying eggs.
Seeds with brown spots or cavities. Cause: Manganese deficiency. Spray plants with seaweed extract every 2 weeks to prevent deficiencies.
Seeds with small, round holes. Cause: Pea weevils. Seeds may be hollow. Fat, white, ■A" long larvae feed on seeds. Adults are 'A" long, dark beetles with light markings that may feed on pea flowers. Discard infested seeds; do not compost them. Cover seeded areas with row cover to prevent adults from laying eggs. Spray plants with pyrethrin if adults are present.
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