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The Carrot Rust Fly [CRF] is a weak flying insect pest that feeds its young on 107 different plants in the carrot family, including carrots, celery, parsnips, celeriac, parsley, and dill. The insect (Psila rosae) earned its common name due to the rusty coloured scarring left by its larvae as they feed on carrots, rendering them unmarketable.
The adult female CRF deposits her eggs in the soil near the base of the base of the carrot, and about one week later the larva hatches and begins to feed on the carrot root. Eventually the larva pupates (forms a cocoon) in the soil, emerges as an adult, and leaves the field to mate. Three generations of CRF may occur in a single year. In southern B.C. the first adult flies generally emerge at the end of April and are present until heavy frost.
Adults are about 6 to 8mm long, with shiny black bodies and reddish-brown head and yellow legs. Typically, the adults congregate at the edge of the field, not near t
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This fungal disease affects cucumber, squash, calendula, hollyhocks, zinnias, and many other garden plants. Small patches of grey appear on otherwise healthy looking leaves, and if it is not treated right away, the fungus will spread to cover the whole leaf, and then most of the leaves on the plant.
Infected leaves cannot produce as much food for the plant as they should. Fewer flowers (and fewer fruits) are produced. Plants may become so weakened that they cannot survive winter.
Powdery mildew is produced by a number of different fungi of the order Erysiphales. Their spores are carried by the wind from plant to plant, and tend to settle on wet leaves. If the humidity is high enough, they don’t require the leaves to actually be wet, but this is why Cucurbits like squash and cucumbers should never be watered overhead. Instead, you wa
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Club root is the thickening and distortion of the roots of Brassicas by the soil fungus Plasmodiophora brassicae. Roots are distended and swollen and may appear to be shaped like fingers or tumors. Infected plants will exhibit day wilting (wilting during the day, recovering at night), and general poor production. Root Brassicas like radishes and turnips may show black lesions.
All Brassicas are prone to this fungal disease: arugula, bok choy, broccoli, Brussels sprouts, cabbage, canola, cauliflower, ching chiang, collards, cress, daikon, gai lan, horseradish, joi choi, kale, kohlrabi, mustards, pac choi, radish, rape, rutabaga, tatsoi, toy choy, turnip, wasabi, and watercress.
The fungus can lay dormant in soil as a cyst for as long as 8 years. Acidic, wet, cool, and poorly drained soils are the most attractive environments. There is no treatment for infected soil, so prevention is absolutely key.
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Known as greenflies in the UK, there are over 4,000 species of aphids worldwide. Only about 250 species are agricultural pests, but they are a genuine nuisance. Like whiteflies, aphids are classed in the order Hemiptera because of their sucking mouthparts. They range in size from 1 to 10 mm long and may be green, grey, or black in colour. Local species usually occur in large numbers along the stems and flower buds of a wide range of plants.
Aphids feed by puncturing the outer cells of plants and sucking out nutrients. This robs the plant of the food it needs to develop properly, and may cause yellow blotches to appear on leaves, and even total collapse of the host plant. The punctured cells become open to viruses and other disease. Aphids also secrete honeydew, which creates large sticky areas on plants and attracts sooty moulds that can then spread quickly over the rest of the plant.
Control
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Whiteflies are members of the order Hemiptera, a group of insects classed together because of the similarity of their sucking mouthparts, with which they feed on the juices of plants. They are closely related to aphids. There are over 1,500 species of whitefly, but two are a particular nuisance in North American greenhouses and gardens, the glasshouse whitefly (Trialeurodes vaporariorum), and the tobacco whitefly (Bemisia tabaci).
Adult whiteflies look like extremely tiny, bright white moths, and are usually seen after they have been disturbed and take to the air. They infest the tops of plants, their growing tips, and the undersides of leaves, where they suck nutrients from the plants’ tissue.
Whiteflies lay their eggs on the undersides of leaves, and this is where the larvae develop and begin to feed on the plants. The pupae
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