Bacterial soft rot, bacterial stem rot

harvest or after that. The pith disintegrates and the stem becomes hollow. Because of the bacterial growth in the pith, the stem seems wet and slimy. Above [...] the fruits, 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 [...] Later the fruit becomes soft and lesion contents become liquid. Life cycle and appearance of Bacterial soft rot, bacterial stem rot Erwinia carotovora

Dwarf bunt

soft white and hard red winter wheats, as well as dwarf bunt. Damage symptoms Tilletia controversa causes (bunted) heads that are slender and remain green [...] are generally broader and the glumes opened wider, than in plants infected with Tilletia tritici and Tilletia laevis Life cycle and appearance of Dwarf bunt [...] The bunt balls are grey-brown. They rupture at harvest and release black, powdery spores, that smell like fish, hence the common name stinking bunt. A

Apple scab

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 [...] 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 already [...] restricted, whereas the lesions caused by conidia extend faster and may merge. Infected fruits and leaves may fall off prematurely. The plants’ defence mechanism

Bacterial spot

petioles and stems and form long dark streaks. On fruits, first small black specks are seen on green fruits. The specks grow into brown spots that look like [...] are also round and small to start with and slightly raised from the leaf surface. They occur on the abaxial (underside of) leaf surfaces and may enlarge into [...] which become rough and light brown. On fruits the spots are first small, circular and green but they turn brown, become raised and look like cracked scab

Gummy stem blight

debris and disinfect the greenhouse Choose a cultivar that is less susceptible to internal fruit rot Use clean propagation material During cropping and between [...] feasible in high-wire crops) Pick and remove dead and diseased leaves Prevent plant diseases by optimizing plant potential and crop resilience. [...] fungal plant pathogen that causes gummy stem blight. Damage symptoms Mycosphaerella cucumis in cucumber causes brown lesions on the foot and higher up on the

Crazy roots, hairy roots, crown gall

which are first white and later turn brown. Only Rhizobium radiobacter causes galls and tumours on underground plant parts and on the crown. Furthermore [...] break open, releasing many bacteria. These are dispersed by rain and wind and by humans and tools. Until now, no bacteria have been isolated from crazy roots [...] roots, hairy roots and crown gall. Damage symptoms The four pathogenic Rhizobium species cause different symptoms, like galls, tumours and excessive root growth

Strawberry

fruit. This means that the fleshy, edible part of the fruit does not develop from the plant’s ovaries, but from the receptacle that holds these same ovaries [...] ovaries. The so-called ‘seeds’ (achenes) that are visible on the strawberry’s skin, are in reality the ovaries of the flower with a seed inside.

Grape downy mildew

mycelium in grape buds and canes. In spring, oospores germinate when temperatures reach 10°C and soils are wet, forming macrosporangia that release zoospores [...] near stomata, and form germ tubes that penetrate through stomata. Inside the plant, hyphae spread intercellularly, forming haustoria that parasitize mesophyll [...] cottony growth. Shoot tips and central axis of flower clusters become distorted into a curl or corkscrew. Inflorescences and young berries turn yellow or

Powdery mildew

dropping leaves that are not infected yet. It depends on the cultivar how soon after infection this happens. In apple, pear, outdoor grown rose and other Rosaceae [...] leaves may turn yellow, curl up or drop off. Life cycle and appearance of Powdery mildew The fungi that cause powdery mildew ( Erysiphe, Podosphaera, Oïdium [...] mildew fungi and especially in greenhouse crops they don’t play a role in the epidemics. Fungal spores germinate on the leaf surface and the germ tubes

Caterpillars

larvae of butterflies and moths. Butterflies and moths form the order Lepidoptera, a very large group with more than 150,000 species, that are easily disti [...] biting and chewing mouthparts and can devour large amounts of plant tissue. Many species cause damage to crops. The most harmful caterpillars that occur [...] on leaves and young shoots, and their enormous feeding capacity can rapidly decimate a plant. Very small caterpillars are not able to chew and therefore