Bacterial canker of tomato

brown centre. In potato, the disease usually only occurs in the second half of the season. The first symptoms are wilting of the lower leaves and subsequent [...] expansion of the wilt upwards. Cutting the stem at the foot shows whitish ooze with bacteria in the case of C lavibacter infection, but other than that the disease [...] then growing into the vessels of the plant. Plant growth is inhibited and the plant wilts because the xylem vessels become blocked. The bacterium can survive

Damping-off

bulbs. At first, the plants recover during the night, but later the plants wilt irreversibly. In potted plants the flower buds fall off. The side roots rot [...] of the root system survives. On the border between air and soil or substrate the plant turns brown. A typical symptom of a Pythium infection is the easy [...] enable the spores to move through water. The zoospores are chemically drawn to the growing roots of young plants and move towards them through the soil water

Black leg of seedlings

later the plants wilt irreversibly. In potted plants the flower buds fall off. The side roots rot and very little of the root system survives. On the border [...] older plants, the leaves lose their turgor or the leaf tips turn yellow, for example in flower bulbs. At first, the plants recover during the night, but later [...] and soil or substrate the plant turns brown. A typical symptom of a Pythium infection is the easy stripping of the skin from the root cortex with a finger

Charcoal rot

Cutting the roots may show the same discolouration of the internal tissues of the main roots. In most crops, necrotic lesions on the roots are the first [...] reported. The density of the microsclerotia in the soil is directly related to disease incidence. Within 24 hours the fungus infects the roots of the host by [...] germ tubes. During the next two days, necrotic spots occur on the roots and the fungus spreads into the cortex and vascular tissue. In the infected host tissues

Crazy roots, hairy roots, crown gall

crown gall The primary source of infection by Rhizobium rhizogenes has not yet been defined. The assumption is that the bacteria survive in the soil, but [...] caused by a change in the hormonal system of the plant resulting from the Rhizobium infection. Rhizobium rhizogenes puts a Ri-plasmid in the plant tissue and [...] Adjust the work order in greenhouses to fit with the hygiene protocol Disinfect the nutrient solution in order to prevent biofilm growth inside the irrigation

Wheat 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 [...] 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 [...] sporidium. Two mating types are distinguished. The filiform basidiospores fuse in the middle with a basidiospore of the other mating type so that H-shaped structures

Loose smut of barley

and the infected seeds are the primary source of inoculum in the next crop. The fungus survives inside the seed and when the seed germinates, the mycelium [...] mycelium of the fungus grows upwards inside the plant into the growing tip and the seed primordia. It only becomes visible after head emergence. The teliospores [...] They germinate within a day and infect the inner tissues of the newly infected seed. During maturation of the seed, the mycelium becomes thick-walled and swollen

Angular leaf spot

lesions on the underside of the leaf. They enlarge to angular spots, often limited by the small veins. The distinctive feature is the way the lesions look [...] visible on the upper side of the leaf as irregular spots which are first reddish brown and then become necrotic. The foliar symptoms are the most important [...] dry leaves or leaves in the soil, but not independantly in the soil. Under humid conditions, bacteria ooze from the lesions on the leaves and form a secondary

Apple scab

available. They infect the plant by direct penetration of the cuticula and then grow between the cuticula and the epidermis of the plant cells. This causes [...] through the cuticula. The asexual conidia are released and repeat the cycle of infection of new plant parts and spore production. In autumn, the fungus [...] have already fallen off the trees. In response to the infection, the plants produce cork as a defence against further growth of the fungus. In cultivars that

Loose smut of wheat

survives inside the seed and when the seed germinates, the mycelium of the fungus grows upwards inside the plant into the growing tip and the seed primordia. It [...] Loose smut of wheat The seeds are infected during flowering and the infected seeds are the primary source of inoculum in the next crop. The fungus survives [...] inner tissues of the newly infected seed. During maturation of the seed, the mycelium becomes thick-walled and swollen as a dormant survival structure. Infection