• Tomato leaf miner

  miners cause damage to plants both directly and indirectly. The most direct damage is caused by the larvae mining the leaf tissue, leading to desiccation, premature [...] larva hatches from the egg, it begins to eat into the leaf at once, tunnelling down into the mesophyll tissue where damage is caused by extensive mines [...] usually in the upper side of the leaf. Egg spots are oval and hard to distinguish from feeding spots. Larvae of Liriomyza bryoniae are transparent white

• Blight of pepper

  enable them to move through water. Infection is usually from the root to the foot, but direct infection of the foot also occurs. Exudates leaking from growing [...] parts, leaf wetness is required. Dispersal is by wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens [...] (thick-walled mycelium cells which are resistant to desiccation) or mycelium. Zoospores are formed from the overwintering structures which infect the host

• Phytophthora blight

  enable them to move through water. Infection is usually from the root to the foot, but direct infection of the foot also occurs. Exudates leaking from growing [...] parts, leaf wetness is required. Dispersal is by wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens [...] (thick-walled mycelium cells which are resistant to desiccation) or mycelium. Zoospores are formed from the overwintering structures which infect the host

• Bacterial soft rot, bacterial stem rot

  lesions first are small and sunken, water-soaked and light to dark brown. They are adjacent to wounds and natural openings at the stem end. Later the fruit [...] has also been found in the gut of insects, possibly spreading from decaying vegetation to the growing crop that way. Erwinia carotovora subsp. carotovora [...] healthy green leaves, but can grow in senescent leaves and from there grow through the petiole to the main stem through the xylem vessels. High humidity is

• Powdery mildew

  harder for the fungi to enter the leaves To reduce chances of powdery mildew in greenhouses, it is advised to first ventilate by only opening the windows [...] upper side of the leaves. Many sweet pepper cultivars react to powdery mildew infection by dropping leaves that are not infected yet. It depends on the [...] structures are produced, the haustoria, from which the fungus penetrates the plant cell and takes up nutrients from the epidermal layer of plant cells. Most

• Black leg of seedlings

  which are resistant to unfavourable conditions, especially dehydration. Germination of the oospores is stimulated by exudates from roots of a susceptible [...] 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 or sudden fl [...] stripping of the skin from the root cortex with a finger nail. Life cycle and appearance of Black leg of seedlings Pythium belongs to the Oomycetes, a separate

• Apple scab

  ascospores mature from bud break onwards. During wet weather, mature ascospores are released from the pseudothecia and carried by wind to newly emerging leaves [...] support. Management should aim to limit primary (ascospore) infections in spring and reduce overwintering inoculum to prevent severe epidemics. Cultural [...] of high apple scab infection risk by combining leaf wetness duration, temperature, and rainfall. This enables growers to optimize treatment timing, reduce

• Pea blight, leaf and pod spot

  more elongated. The lesions are light brown, sunken and surrounded by a dark brown to red-brown border. The first infection is often on the primary leaves [...] the lesions, pycnidia are formed from which orange-red masses of two-celled conidia are exuded. Secondary infection is by splash dispersal of these conidia [...] at temperatures below 20 °C and the spores require water for dispersal. How to prevent Pea blight, leaf and pod spot Grow peas in arid regions Use clean

• Mealybugs and scales

  leads to sooty mould. Infestations reduce plant vigor, fruit quality and overall yield. Effective control of mealybugs and scales is essential to maintain [...] the sap of plants and are mostly host plant specific. Apart from the damage they cause by sucking plant sap, mealybugs and soft scales also produce honeydew [...] females extract the sap from the plant, stunting growth and causing deformation and/or yellowing of leaves, sometimes followed by defoliation. The overall

• Loose smut of barley

  Infection mostly occurs before pollination and within one to two days after pollination. How to prevent Loose smut of barley Use clean seed: Apply systemic [...] infected seed and prevent the use of seeds from infected fields for further cropping Prevent plant diseases by optimizing plant potential and crop resilience [...] also known as barley smut, or loose smut of barley. Damage symptoms Infection by Ustilago nuda f. sp. hordei r emains invisible until head emergence. The first