Leaf Spot Prevention In Cucumbers
Members of the extensive cucurbit family, cucumbers are a staple in many vegetable gardens. The plants are prolific producers and gardeners have dozens of varieties to choose from when planning their vegetable patch. Because cucurbits are susceptible to a wide variety of diseases and pests, breeders work constantly to develop cultivars with resistance to as many of these problems as possible. No one variety resists all diseases, so gardeners need to do as much as they can to protect their cucumber plants.
Caused by Pseudomonas lachrymans, angular leaf spot causes water-soaked, angular leaf spots that may appear greasy and have yellow halos. The spots do not cross main veins. Initially green, the spots may turn brown and dry up, developing tattered-looking holes in the centers. The disease also infects the stems and fruit of the cucumber plant. To prevent angular leaf spot, plant seeds or seedlings labeled as resistant varieties. Buy only certified disease-free seeds. Don’t use high-nitrogen fertilizer, avoid overhead irrigation and don’t do gardening chores while the cucumber plants are wet. Rotate crops and plant cucumbers away from other cucurbit species. After harvest, plow the cucumber plants under as deeply as you can. Remove all surface plant debris and destroy it away from the garden.
Bacterial Leaf Spot
Leaf spots caused by other bacterial infections can infect the foliage and the fruit, causing the cucumbers to rot on the plant. The spots are very small, distinguishing them from angular leaf spot, and spots are not confined by the veins on the cucumber plant’s leaves. Bacterial leaf spots cause lesions on the cucumber which can penetrate the cucumber rind into the flesh of the fruit. Plant resistant varieties and practice prevention as for angular leaf spot disease.
Cucumber Mosaic Virus
Yellow spots and streaks on cucumber leaves, yellow leaf veins, ring spots or patterns of different shades of green are all symptoms of cucumber mosaic virus. This disease can be spread by insects such as aphids, via weeds and by failure to disinfect gardening tools and your hands after contact with an infected plant. Cucumber mosaic virus cannot be diagnosed from symptoms alone. Since there are no chemical treatments or preventives for cucumber mosaic virus, remove infected plants and destroy them away from the garden. Grow cucumbers from seed rather than seedlings. Keep the garden weed-free and disinfect gardening tools between cuts and between plants to avoid spreading the disease. Wash hands thoroughly after handling an infected cucumber plant. If you wear gloves while gardening, change or wash the gloves before handling healthy plants.
Fungal Leaf Spots
Myriad fungal infections can attack cucumber plants, including alternaria, anthracnose, downy and powdery mildews, gunny stem blight and phytophthora, septoria and ulocladium. Most produce tan or brown spots, sometimes with yellow halos. The spots often appear sunken or wet, and the centers may fall out, leaving the cucumber plant’s foliage looking ragged. Downy and powdery mildew produce white spots. These leaf spot infections may spread to the stems and the fruit of the cucumber plant, limiting or ruining the harvest. Proper diagnosis of the infection is crucial to treating or preventing it. Many cooperative extension service offices and university horticulture departments can diagnose leaf infections, sometimes for free. To prevent fungal infections, plant resistant cucumber varieties, if available. Rotate crops in the vegetable garden each year. Make sure the cucumber plants have good air circulation and are not crowded together. Remove severely infected plants and destroy them away from the garden. Avoid overhead watering. If the infection is light, you may be able to prune away the diseased area and prevent the infection from spreading. Always disinfect pruning tools between pruning cuts and in between each plant.
Leaf Spot Prevention In Cucumbers. Members of the extensive cucurbit family, cucumbers are a staple in many vegetable gardens. The plants are prolific producers and gardeners have dozens of varieties to choose from when planning their vegetable patch. Because cucurbits are susceptible to a wide variety of diseases and …