• Black sigatoka disease

  conidia. The ascospores are wind-dispersed over longer distances, the conidia are splash-dispersed within the crop. Both types of spores cause the exact same [...] them, so the spores cannot be discharged from the lower leaves in the stack Use under-canopy (drip) irrigation to reduce splash dispersal Lower the humidity [...] or streaks on leaves of about one month old. The symptoms run parallel to the veins. Within a few days, the spots become a few centimetres in size and turn

• Cottony soft rot

  base and the roots, whereas the ascospores infect the above-ground plant parts. In greenhouses, usually only mycelium is produced by the germinating sclerotia [...] sclerotia. The fungus grows quite rapidly inside the plant and kills the host cells. On the infected plant tissue white, fluffy mycelium occurs with new [...] Damage symptoms The first symptoms of a cottony soft root ( Sclerotinia sclerotiorum ) infection are water-soaked lesions at the stem base. The plant above

• Phytophthora blight

  fungal growth on the leaves. The centre is grey-brown with a light-green edge. On the stem, elongated brown lesions occur, usually circling the stem. On potato [...] from the root to the foot, but direct infection of the foot also occurs. Exudates leaking from growing root tips promote germination and attract the zoospores [...] 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 can readily

• Bacterial wilt, brown rot

  s roots on the stem. The vascular stem tissue is coloured brown and when the stem is cut, bacterial slime oozes from the wound. This is the way to distinguish [...] signs of wilting during the day which may disappear in the early stages of infection. Under conditions favourable for the bacteria, the whole plant will wilt [...] common with bacterial slime oozing from the cut. When the bacteria transfers to young plants through infected tubers, the wilting and collapse of plants happens

• Bacterial soft rot, bacterial stem rot

  wilt at the time of first harvest or after that. The pith disintegrates and the stem becomes hollow. Because of the bacterial growth in the pith, the stem [...] stem seems wet and slimy. Above or below the hollow stem the vascular tissue keeps its normal colour. On the fruits, lesions first are small and sunken, w [...] plants or in the soil in low densities. It has also been found in the gut of insects, possibly spreading from decaying vegetation to the growing crop that

• Fusarium wilt

  oxysporum is the only Fusarium that actually grows inside the vessel system of the host plant and spreads upwards inside the plants. The other species [...] Fusarium oxysporum is the species causing vascular wilt. First the leaves turn yellow and wilt, mostly on one side of the plant. Finally, the whole plant wilts [...] brown discolouration of the xylem vessels which can be seen when the stems are cut. In banana, whole plantations may die and the soil may not be suitable

• Pea blight, leaf and pod spot

  transmitted on the outside of the seed coat and cause primary infection. The conidia germinate and infect through the stomata or directly through the cuticle [...] on leaves, stems and pods of peas. The spots on leaves and pods are round, on the stems they are 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 fungus is seed borne and thus also causes post-

• Early blight

  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 [...] 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 [...] 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

• False codling moth

  and brown as the damage tissue decays. The mature larvae enlarge the hole to leave the fruit and pupate. Excreta can be found within the larvae tunnels [...] fruit and drops to the ground where it pupates in the top layer of the soil. The moths emerge after a couple of weeks. The life cycle varies between 5 weeks [...] moth Eggs are laid singly on the surface of the fruit and resemble a saucer-shaped dome. After a few days the eggs hatch and the neonate larvae finds a suitable

• Persea mite

  leaves, primarily on the underside where the mites form small, web-covered colonies along the main veins. Their feeding punctures the leaf tissue, resulting [...] Life cycle The persea mite has a fast life cycle, allowing populations to build up quickly in avocado crops when conditions are favourable. The pest develops [...] stages mainly occurring on the underside of avocado leaves within protective webbing. Female persea mites lay their eggs along the leaf veins, where larvae