• Corn earworm

  January 1, 1970

  ears of corn. The larvae feed on the hairs of the young corn and on the young kernels at the tip of the cob. During the third instar, the larvae turn c [...] pepper, and tomato. They primarily feed on flowers and fruit from the host plant, as well as on the corn of immature cobs and ears. Adults of corn earworm are [...] trace, which makes it necessary to open the crop to detect the pest. Life cycle and appearance of the corn earworm The eggs of corn earworm are a milky-white

• Gummy stem blight

  January 1, 1970

  be recognized from the outside by the small narrowing of the tip of the mature fruits. The symptoms on stems, leaves and inside the fruits may occur together [...] through the flowers. The newly produced ascospores are dispersed by air and the conidiospores by water drops, tools and hands of workers. The ascospores [...] higher up on the stem. On the lesions, golden-brown gummy drops occur, hence the name gummy stem blight. On the lesions, black specks, the new fruiting

• Damping-off

  January 1, 1970

  first, the plants recover during the night, but later the plants wilt irreversibly. In potted plants the flower buds fall off. The side roots rot and very [...] of the root system survives. On the border between air and soil or substrate the plant turns brown. A typical symptom of a Pythium infection is the easy [...] enable the spores to move through water. The zoospores are chemically drawn to the growing roots of young plants and move towards them through the soil water

• Loose smut of wheat

  January 1, 1970

  next crop. The fungus survives inside the seed and when the seed germinates, the mycelium of the fungus grows upwards inside the plant into the growing tip [...] cycle and appearance of Loose smut of wheat The seeds are infected during flowering and the infected seeds are the primary source of inoculum in the next [...] within a day and infect the inner tissues of the newly infected seed. During maturation of the seed, the mycelium becomes thick-walled and swollen as a

• Bacterial spot

  January 1, 1970

  halo. In pepper, the spots on the leaves are also round and small to start with and slightly raised from the leaf surface. They occur on the abaxial (underside [...] irrigation. Infection is through stomata and wounds. The dispersal is in windblown water drops, mechanical means such as clipping and handling and aerosols. Many [...] field and on diseased plant debris. The bacteria are also seed-transmitted. Disease development is favoured by temperatures between 24 and 30 °C and high p

• Apple scab

  January 1, 1970

  petioles and fruits and sometimes on twigs and bud scales. The lesions are olive-green. When spores are produced, the lesions become grey and fluffy. The lesions [...] wind-dispersed to the fruit trees and will germinate if free water is available. They infect the plant by direct penetration of the cuticula and then grow between [...] through the cuticula. The asexual conidia are released and repeat the cycle of infection of new plant parts and spore production. In autumn, the fungus

• Black rot of carrots

  January 1, 1970

  General The only known stage in all Alternaria species is the asexual stage. Conidia and mycelium overwinter in the soil and on crop residues and cause primary [...] three days later and sporulation within five days. Infection is both direct and through wounds and stomata. Spores are dispersed by wind and in some species [...] spores surviving in the soil are the main source of infection. Especially wheat and barley reduce the number of surviving conidia in the soil. Use resistant

• Black leg of seedlings

  January 1, 1970

  later the plants wilt irreversibly. In potted plants the flower buds fall off. The side roots rot and very little of the root system survives. On the border [...] between air and soil or substrate the plant turns brown. A typical symptom of a Pythium infection is the easy stripping of the skin from the root cortex [...] enable the spores to move through water. The zoospores are chemically drawn to the growing roots of young plants and move towards them through the soil water

• Cottony soft rot

  January 1, 1970

  directly and form mycelium or produce apothecia (fruiting bodies) containing ascospores. The mycelium infects the stem base and the roots, whereas the ascospores [...] rapidly inside the plant and kills the host cells. On the infected plant tissue white, fluffy mycelium occurs with new dark sclerotia. The fungus also infects [...] infection are water-soaked lesions at the stem base. The plant above it wilts and rots. White, fluffy fungal mycelium grows on the lesions, giving this disease

• Grape downy mildew

  January 1, 1970

  viticola , is one of the most important diseases in wine and table grape production worldwide. The disease spreads rapidly under warm and wet conditions [...] shoots, and young berries, often resulting in severe yield and quality losses. Infections during flowering and early berry development pose the greatest [...] n (depending on temperature and humidity), the disease is often well-established before it can be visually detected in the field. Leaf symptoms Yellowish