• Angular leaf spot

  January 1, 1970

  also introduced in a crop in new transplants. This bacterium is very resistant to desiccation and can survive well in dry leaves or leaves in the soil, but [...] cycle and appearance of Angular leaf spot Xanthomonas fragariae overwinters in plants and dead leaves, that become the primary source of infection in the [...] both passively and actively. Infection and disease development are favoured by temperatures around 20 °C during the day and cold nights, in combination with

• Amblyseius swirskii

  January 1, 1970

  thrips and whitefly. Feeding behaviour of Amblyseius swirskii Predatory mites pierce their prey and suck out the contents. In addition to thrips and whiteflies [...] deutonymph, and adult. Eggs are laid on the underside of leaves, often in the axil of veins. They are oval, white and are approximately 0.14 mm in diameter [...] white in colour, and have a flat, elongated body. They are roughly 0.4 mm in length. Males are smaller than females. The mites are very mobile and actively

• Bacterial canker of tomato

  January 1, 1970

  the plants in greenhouse crops and by water in field crops, for example through splashes of rain or irrigation. Both in greenhouses and in the field, spraying [...] tested and disinfected seed Use only tested and certified seed potatoes Apply strict hygiene measures in greenhouse crops: remove infected plants in closed [...] protective clothing and gloves, disinfect tools and greenhouse structures Use a crop rotation in field crops of at least two years and alternate with a non-host

• Phytoseiulus persimilis

  January 1, 1970

  d spider mite (Tetranychus urticae) and has been used in many crops worldwide, mainly in greenhouses, but also in outdoor crops such as strawberries. This [...] agent used commercially in greenhouses and Koppert’s very first product in 1967. It is a specialist predator of spider mites and can control spider mite [...] deutonymph and adult, except for the resting period in the larval and nymphal stages. On plants, the oval eggs are usually deposited close to, or in a spider

• Crazy roots, hairy roots, crown gall

  January 1, 1970

  growth (crazy roots). In greenhouse vegetables, the roots overgrow the substrate and in severe epidemics the drippers get clogged. In tomato, excessive vegetative [...] rain and wind and by humans and tools. Until now, no bacteria have been isolated from crazy roots. This disease seems to be caused by a change in the hormonal [...] which are first white and later turn brown. Only Rhizobium radiobacter causes galls and tumours on underground plant parts and on the crown. Furthermore

• Neoseiulus californicus

  January 1, 1970

  Phytoseiidae family: egg, larva, proto- and deutonymph, and adult males and females. Adult mites are lighter and have a flatter more elongated body than [...] at temperatures between 13 and 32°C (55 and 90°F) and is sensitive to relative humidity below 60%. Neoseiulus californicus in bottles The predatory mite [...] predatory mites multiply in the sachet and disperse into the crop over a period of several weeks. Hang sachets in sheltered locations in the crop, avoid hanging

• Black leg of seedlings

  January 1, 1970

  temperatures and causes among others cereal diseases. Damage symptoms Pythium affects roots, in particular those of seedlings. Infected plants lag in growth [...] 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 [...] are in a sub-optimal condition or suffer from stress, caused for example by too much water, too high or low temperatures or sudden fluctuations in temperature

• 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 [...] unripe fruiting bodies in infected fallen leaves or in lesions on twigs. These unripe fruiting bodies, or pseudothecia ripen in winter and form ascospores. Depending [...] are released and repeat the cycle of infection of new plant parts and spore production. In autumn, the fungus produces new pseudothecia in leaves that have

• Black root rot of cucurbits

  January 1, 1970

  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 [...] are slightly sunken and are mostly formed around the point of attachment of lateral roots and root hairs. The lesions may grow and encircle the root. The [...] sclerotioides survives in the soil and is a strong saprophytic competitor, which means it can rapidly colonize ‘clean’ or sterilized soil and substrate. It aggregates

• Verticillium wilt

  January 1, 1970

  system usually stays mostly intact. In rose, branches die off from the top and purple brown stripes occur on the stem. In tomato, sometimes V-shaped lesions [...] periods (many years) in the soil as microsclerotia, small hard survival structures that can withstand high and low temperatures and dehydration. Verticillium [...] fungus and the gum causes the xylem vessels to get blocked, which in turn causes the plant to wilt. Spores may be wind-dispersed to new hosts. In the senescent