Onions, Garlic: Gray mold categories: Onions, Garlic Onions, Garlic Diseases Vegetables revision date: 2024-06-05 02:07 Botrytis gray mold on onionPhoto by: R.S. Byther Biology Gray mold is a fungal disease primarily found on garlic. It attacks the tissues of the neck and bulb and occasionally causes a leaf blight. Symptoms of infection typically appear on […]
Onions, Garlic: Neck rot categories: Onions, Garlic Onions, Garlic Diseases Vegetables revision date: 2022-12-07 12:00 Onion neck rot symptomsPhoto by: L.J. du Toit Biology Neck rot is a fungal disease which can affect onions and related species. Infection typically occurs in the field, but symptoms often do not appear until bulbs are in storage. The […]
Onions, Garlic: White rot categories: Onions, Garlic Onions, Garlic Diseases Vegetables revision date: 2022-12-07 12:00 Sclerotia on surface of white rot-infected bulbsPhoto by: R.S. Byther Biology White rot is a fungal disease which affects onions and related species. Cool, wet conditions may be followed by wilting and yellowing of leaves beginning at the base of […]
Onions, Garlic: Onion maggot categories: Onions, Garlic Onions, Garlic Insects Vegetables revision date: 2022-12-07 12:00 Onion maggot and damagePhoto by: E.P. Breakey Biology The onion maggot is the larvae of a slender gray fly about 1⁄4″ in length. Female flies lay eggs near the base of host plants including onion, garlic, leek, and shallot. The […]
Onions, Garlic: Onion thrips categories: Onions, Garlic Onions, Garlic Insects Vegetables revision date: 2024-06-05 08:28 Onion thripsPhoto by: Unknown Biology Onion thrips are tiny, slender insects about 1⁄16″ long. They are yellowish to dark in color, depending on age. They feed on tender inner leaves, causing longitudinal silvery to white mottling or streaking along the […]
Lettuce: Anthracnose categories: Lettuce Lettuce Diseases Vegetables revision date: 2022-12-07 12:00 Lettuce anthracnose magnifiedPhoto by: R.S. Byther Biology Anthracnose of lettuce is a fungal disease favored by cool, wet weather. The disease is also known as shothole because of the characteristic symptoms. Lower leaves develop small, water-soaked spots which quickly darken and enlarge. The centers […]
Lettuce: Aster yellows categories: Lettuce Lettuce Diseases Vegetables revision date: 2022-12-07 12:00 Biology Aster yellows is caused by a phytoplasma which is a microorganism found in the phloem tissue of a plant. The phytoplasma is spread by leafhoppers and can also affect carrot, onion, potato, celery, and other crops, weeds, and ornamentals. Initial symptoms are […]
Lettuce: Beet western yellows virus categories: Lettuce Lettuce Diseases Vegetables revision date: 2022-12-07 12:00 Biology Beet Western Yellows is a virus which affects many garden plants and weed species. The virus is transmitted by aphids, including the green peach aphid. Older leaves are affected first. Yellowing begins at the margin and progresses inward, with the […]
Lettuce: Bottom rot categories: Lettuce Lettuce Diseases Vegetables revision date: 2022-12-07 12:00 Lettuce bottom rotPhoto by: R.S. Byther Biology Bottom rot of lettuce is caused by a soil-borne fungus that is common in wet soils. Head lettuces, particularly the ‘Big Boston’ types, are attacked as they near maturity. The stems and midribs of lower leaves […]
Lettuce: Damping-off categories: Lettuce Lettuce Diseases Vegetables revision date: 2022-12-07 12:00 Damping-off of cucumber seedlingsPhoto by: R.S. Byther Biology Damping-off is caused by fungi that remain in the soil for long periods of time. Seeds decay without germinating. Seedlings may be infected and fail to emerge from the soil. Emerged seedlings are also attacked, causing […]
Lettuce: Downy mildew categories: Lettuce Lettuce Diseases Vegetables revision date: 2022-12-07 12:00 Lettuce leaf infected with downy mildew fungusPhoto by: R.S. Byther Biology Lettuce downy mildew is caused by a fungus which survives the winter on wild hosts and weeds. Light green or yellowish areas on the upper leaf surface are in places where the […]
Lettuce: Lettuce big vein virus categories: Lettuce Lettuce Diseases Vegetables revision date: 2022-12-07 12:00 Lettuce big vein virus symptomsPhoto by: R.S. Byther Biology Lettuce Big Vein Virus is transmitted by a fungus which inhabits the roots. Virus infection causes tissues next to veins to become clear, resulting in an enlarged appearance of the veins. The […]
Lettuce: Aphids categories: Lettuce Lettuce Insects Vegetables revision date: 2024-06-05 08:28 Aphid colony on leafPhoto by: A.L. Antonelli Biology Aphids are small, soft-bodied, pear-shaped insects. They may vary in color from yellow to green to dark. Aphids typically feed in colonies on the leaves, often preferring the newer growth. Infested leaves turn yellow and may […]
Lettuce: Slugs categories: Lettuce Lettuce Insects Vegetables revision date: 2024-06-05 10:41 Slug damage and slimePhoto by: R.S. Byther Biology Slugs are common garden pests in western Washington. They resemble snails, but lack shells. They may vary from as little as 1⁄4″ up to several inches in length, depending on age and species. Slugs often leave […]
Cucumber, Pumpkin, Squash: Angular leaf spot categories: Cucumber, Pumpkin, Squash Cucumber, Pumpkin, Squash Diseases Vegetables revision date: 2022-12-07 12:00 Angular leaf spot on cucumberPhoto by: R.S. Byther Biology Angular leaf spot is a bacterial disease which can affect cucumber and many related species. Leaves initially develop small, water-soaked spots which enlarge until limited by the […]
Cucumber, Pumpkin, Squash: Cucumber mosaic virus categories: Cucumber, Pumpkin, Squash Cucumber, Pumpkin, Squash Diseases Vegetables revision date: 2022-12-07 12:00 Biology Cucumber mosaic is a viral disease of cucumbers, melons, squash, and other plants. It is spread primarily by aphids, but can also be transmitted by mechanical means, infected seed, and by cucumber beetles. The early […]
Cucumber, Pumpkin, Squash: Curly top (Beet curly top virus) categories: Cucumber, Pumpkin, Squash Cucumber, Pumpkin, Squash Diseases Vegetables revision date: 2022-12-07 12:00 Curly top virus symptoms on tomatoPhoto by: R.S. Byther Biology Curly top is caused by a virus transmitted by the beet leafhopper. Many crops are affected, including tomato, bean, squash, cucumber, and pepper. […]
Cucumber, Pumpkin, Squash: Damping-off categories: Cucumber, Pumpkin, Squash Cucumber, Pumpkin, Squash Diseases Vegetables revision date: 2022-12-07 12:00 Damping-off of cucumber seedlingsPhoto by: R.S. Byther Biology Damping-off of seeds and seedlings is caused by fungi that remain in the soil for long periods of time. Infected seeds decay without germinating. Seedlings may be infected and fail […]
Cucumber, Pumpkin, Squash: Pollination failure categories: Cucumber, Pumpkin, Squash Cucumber, Pumpkin, Squash Diseases Vegetables revision date: 2022-12-07 12:00 Biology Fruits may begin to develop without pollination, but must be pollinated to continue normal growth. The unpollinated fruit remain small and may show a rot beginning at the blossom end. These fruits usually turn yellow and […]
Cucumber, Pumpkin, Squash: Powdery mildew categories: Cucumber, Pumpkin, Squash Cucumber, Pumpkin, Squash Diseases Vegetables revision date: 2024-06-05 10:24 Powdery mildew on cucumber leavesPhoto by: R.S. Byther Biology Powdery mildew is a common fungal disease of squash. Upper and lower leaf surfaces and stems are typically affected. Small, white spots quickly enlarge into patches of characteristic […]