• Early blight

  January 1, 1970

  occur at the side of the stem. Life cycle and appearance of Early blight From the primary infection of leaves, Alternaria solani can spread to the flowers [...] production) and to the crown. Sporulation of Alternaria occurs at temperatures from 2-4 °C up to 28-30 °C (optimum temperatures lie between 15 and 28 °C) and

• Damping-off

  January 1, 1970

  is stimulated by exudates from roots of a susceptible host nearby. The oospores germinate and form so-called sporangia from which subsequently zoospores [...] usually only affect plants that are in a sub-optimal condition or suffer from stress, caused for example by too much water, too high or low temperatures [...] typical symptom of a Pythium infection is the easy stripping of the skin from the root cortex with a finger nail. Life cycle and appearance of Damping-off

• Downy mildew of rose

  January 1, 1970

  nutrients from the living plant cells. The pathogens continue to grow inside the leaves and after a while new spore-bearing structures are protruding from the [...] grey-brown. This is, in fact, the sporulation of the pathogens extruding from the stomata. In lettuce, the foot is infected first and this causes the plant [...] Oomycetes and related to Pythium and Phytophthora . They survive as oospores. From these oospores or surviving mycelium sporangia are formed, structures in

• Phytophthora blight

  January 1, 1970

  water. Infection is usually from the root to the foot, but direct infection of the foot also occurs. Exudates leaking from growing root tips promote g [...] cells which are resistant to desiccation) or mycelium. Zoospores are formed from the overwintering structures which infect the host. Zoospores are spores [...] Dispersal is by 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

• Black sigatoka disease

  January 1, 1970

  They enter the leaf through the stomata. After infection, hyphae emerge from the stomata and either develop into conidiophores with new conidia or grow [...] infected leaves or at least stack them, so the spores cannot be discharged from the lower leaves in the stack Use under-canopy (drip) irrigation to reduce

• Eretmocerus eremicus

  January 1, 1970

  preventively soon after planting of the crop. Introduction rates typically range from 1-10 per m2/release. Releases should be repeated at least 3 times at weekly [...] immature whitefly nymphs, and upon hatching, the larvae consume the host from within. The larvae use their specialized mouthparts to feed on the internal

• Anagyrus vladimiri

  January 1, 1970

  Anagyrus vladimir is available in a bottle ( Citripar ). Remove the label from the bottle according to the instructions Hang the bottle in the crop, out [...] te first signs of infestation appear. Introduction rates typically range from 0.1-0.5 per m 2 /release. Releases should be repeated at least 3 times at [...] larvae feed on the internal tissues of the mealybug, gradually consuming it from within. This internal feeding ensures the larval wasps have a constant and

• Tomato leafminer

  January 1, 1970

  tomato leaf miner ( Tuta absoluta ) are cylindrical. Their colour varies from creamy white to bright yellow, darkening in the embryonic phase and becoming

• Southern European marshland pyralid

  January 1, 1970

  (Duponchelia fovealis) is a polyphagous species feeding on a wide range of hosts from 38 plant families. They include ornamental crop plants, such as roses and

• Bacterial soft rot, bacterial stem rot

  January 1, 1970

  densities. It has also been found in the gut of insects, possibly spreading from decaying vegetation to the growing crop that way. Erwinia carotovora subsp [...] cannot infect healthy green leaves, but can grow in senescent leaves and from there grow through the petiole to the main stem through the xylem vessels