• Wheat bunt

  heads. The glumes are opened either on some or on all spikelets, showing the bunt (smut spore) they contain, which is larger than a normal kernel. The 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 [...] ed. The filiform basidiospores fuse in the middle with a basidiospore of the other mating type so that H-shaped structures are formed. These can germinate

• Blight of pepper

  zoospores. The pathogen grows into the stem and on the plant surface and new sporangiophores (structures containing sporangia, a type of spores) with sporangia [...] 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 [...] and crown rot in potted plants. The small roots die and brown-black lesions occur on the larger roots. Plants wilt and the crown leaves drop off. Life cycle

• Tobacco whitefly

  cause to a crop is the result of sucking out the sap from the plant leaves and secreting honeydew. This can have the following consequences: If the population [...] (crawlers) are mobile, whereas the rest of the larvae stadia remain flattened on the leaf. The fourth larva stadium develops into a yellow, almost circular so [...] which the red eyes and white wings of the adult are already clearly visible. These pupae are found on the oldest leaves. The adult emerges from the pupa

• Leaf stripe

  graminea is monocyclic, which means there is only one disease cycle during the cropping season. The fungus is seed-borne and this systemic infection is the [...] primary infection. The fungus spreads from the seed into the seedling. Conidia are produced on the infected leaves when humidity is high and wind-dispersed [...] merge. Eventually this leads to the death of the leaf. The leaf splits at the end which makes it look shredded. This is typical for this disease. Infected

• Brown root rot, corky root rot

  lesions. On older roots, the outer layers become swollen and corky and gradually break off. The corky areas often occur as horizontal bands on the roots with [...] fungus is a poor competitor against a balanced microbial population in soil. How to prevent Brown root rot, corky root rot Field crops: Fumigate the soil [...] lycopersici is a fungal plant pathogen, infecting tomatoes and aubergine. It causes brown root rot and corky root rot. Damage symptoms The first signs

• Diamond back moth

  regions. Damage symptoms The caterpillar is a surface feeder. They feed from the lower leaf surface, leaving the wax layer on the upper surface intact, thereby [...] one-third of the forewing is ochreous-white, with a nearly white upper edge. In females, the upper two-thirds of the forewings are light ochreous and the markings [...] markings are like those of the males. The back is marked with a broad cream or light brown band along the back, which is sometimes constricted to form one

• Broad mite

  lay their eggs mainly on the underside of the leaf or on the fruit surface. The elongated, oval eggs are firmly attached to the surface and are rather [...] to the damage caused by viruses. The typical pattern of damage consists of malformation and distortion of the above-ground growth of the plant. The mites [...] show a preference for young, developing plant tissue, like the growing tips, young leaves and flower buds. The mechanism causing the deformation is not

• Cutworms

  separately or in batches on the ground, or on the plant close to ground level. The larvae are yellowish when hatching with a dark head capsule and prothoracic [...] marginal stripe. The wingspan is about 40-55 mm and the dorsal thorax is covered with close-lying hairs. The eggs are white at first but rapidly turn darker [...] species are for instance the black cutworm Agrotis ipsilon and the turnip moth Agrotis segetum . The larvae of these moths usually feed on roots and plant parts

• Potato aphid

  General The potato aphid ( Macrosiphum euphorbiae ) is of North American origin, but is these days distributed throughout the world. It is a highly polyphagous [...] from the plant and disturb the balance of growth hormones. As a result, the plant’s growth is retarded giving rise to deformed leaves or, if the infestation [...] protein. The excess sugar is secreted in the form of honeydew, making the crop and its fruit sticky. Black fungal moulds ( Cladosporium spp.) grow on this

• Whitefly

  damage The larvae need a lot of nutrients for growth, and thus consume a large quantity of plant sap. This contains a high proportion of sugar, and the excess [...] large, feeding on plant sap can affect the physiology of the plant, as a result of which growth is retarded. In full sunlight, leaves can wilt and drop. Such [...] crops. This is particularly important in ornamentals . The honeydew deposited on fruit makes it sticky. Dirt adheres to the fruit, and the growth of sooty