Black root rot of cucurbits

restricted to a few of the roots but in severe cases all roots may be infected. At the final stage of the disease, only vascular tissue remains because the cortex [...] away. Infection in the early stages of the crop results in stunted growth and smaller leaves with an intense green colour. Severe infection in this stage may [...] may kill the plants. In case of a less severe infection, the vines may wilt at a late stage of the crop, but when water supply is in any way limited during

Grape downy mildew

during the growing season. The pathogen overwinters as oospores in fallen, infected leaves. In mild climates, it can also survive as mycelium in grape buds [...] instead of overhead irrigation to reduce leaf wetness. Ploughing to bury oospores in leaf litter and avoiding prolonged irrigation to prevent oospore germination [...] management is essential in wet climates and during unusually wet seasons in typically dry areas. Most grape cultivars are highly susceptible to downy mildew. Breeding

Apple scab

fungus produces new pseudothecia in leaves that have already fallen off the trees. In response to the infection, the plants produce cork as a defence against [...] mechanism is to produce corky rings around the lesions to prevent further invasion of tissue by the fungus. Late fruit infection only results in small dark [...] overwinters in the form of unripe fruiting bodies in infected fallen leaves or in lesions on twigs. These unripe fruiting bodies, or pseudothecia ripen in winter

Dwarf bunt

sporidia infect the wheat seedlings even before emergence and the fungi grow inside the plants to the growing tip. The fungi grow between the plant cells and [...] teliospores in the soil or on seed. The soil-borne teliospores are the main source of primary infection. The soil-borne teliospores may survive in soil without [...] allowing the teliospores to fall to the ground. Additionally, these teliospores contaminate healthy kernels, which in turn become a source of disease in the

Onion thrips

petals and in the soft parts of stalks. They are inserted into the plant tissue with a saw-like ovipositor. Larvae are light to yellowish green in colour, [...] cause damage to plants by piercing the cells of the surface tissues and sucking out their contents, causing the surrounding tissue to die. The resulting [...] develops in six stages: egg, two larval instars, prepupa, pupa, and finally the adult insect. The eggs of the onion thrips (Thrips tabaci) are laid in leaves

Phytophthora blight

wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens via water, since the zoospores can readily [...] fungal growth on the leaves. The centre is grey-brown with a light-green edge. On the stem, elongated brown lesions occur, usually circling the stem. On potato [...] flagellae which enable them to move through water. Infection is usually from the root to the foot, but direct infection of the foot also occurs. Exudates

Bacterial wilt, brown rot

disappear in the early stages of infection. Under conditions favourable for the bacteria, the whole plant will wilt soon after the first symptoms appear [...] into the xylem vessels. In potato, it is tuber-borne. Spread from plant to plant results from bacteria moving from the roots of infected plants to neighbouring [...] common with bacterial slime oozing from the cut. When the bacteria transfers to young plants through infected tubers, the wilting and collapse of plants happens

Cabbage

biennial plant with green, white or purple leaves. This plant is usually grown as an annual vegetable crop for consumption. Cabbage heads come in various sizes [...] sizes and their weight usually varies between 0.5 to 4 kilograms (or 1-9 lbs).

Aphidius colemani

typical of the Aphidiidae. First the host is examined by drumming with the antennae. This gives the wasp the information about whether the aphid is the right [...] causing aphids to drop from the leaf and fall to the ground. Although many aphids die as a result, many will survive and migrate to other plants to begin new [...] all items How to use Aphidius colemani The parasitic wasp is available in a bottle ( Aphipar ). Spread the material on rock wool slabs or in Diboxes Make

Turf and grass

pitches and football fields, turf provides the perfect base for a wide variety of sporting grounds around the world. It is also prized as a ground cover [...] cover for recreational purposes such as green urban areas and private gardens.