Bacterial wilt, brown rot

35-37 °C, the optimum for Race 3 is 27 °C, which makes it more dangerous in temperate regions. It survives well in water and in many different soil types [...] quarantine organism in Europe and considered a bioterrorist organism in the United States. It is a commonly found soil-inhabitant in tropical and subtropical [...] xylem, causing bacterial wilt and brown rot in a very wide range of potential host plants. Damage symptoms In potato, field symptoms of Ralstonia solanacearum

Fusarium spp.

be seen when the stems are cut. In banana, whole plantations may die, and the soil may not be suitable for planting for many years subsequently. F. gra [...] also produce ascospores. In general, the life cycle of different Fusarium species is similar. Fusarium overwinters for many years in the soil, and on crop [...] seed-borne or takes place as infection of the roots at the root tip, or in small wounds, for example where lateral roots branch off the tap root. F. oxysporum

Powdery mildew

colonies mostly occur in these crops. In covered roses, the colonies appear first and foremost on the upper side of the leaves. In most crops, the white [...] Ascospores have not been found yet for all powdery mildew fungi and especially in greenhouse crops they don’t play a role in the epidemics. Fungal spores germinate [...] explode when in contact with water for no more than a few hours. Powdery mildew spores, either ascospores or conidia, don’t need nutrients or water for germination

Black leg of seedlings

are in a sub-optimal condition or suffer from stress, caused for example by too much water, too high or low temperatures or sudden fluctuations in temperature [...] Pythium affects roots, in particular those of seedlings. Infected plants lag in growth. Seedlings fall over (‘damping-off’). In slightly older plants, [...] tips turn yellow, for example in flower bulbs. At first, the plants recover during the night, but later the plants wilt irreversibly. In potted plants the

Gummy stem blight

makes it harder for the fungi to enter the leaves Pick flowers within two days after opening in areas suspected of disease (only feasible in high-wire crops) [...] ascospores are the main source of dispersal of disease upwards in the crop and the conidia for spread of the disease downwards. How to prevent Gummy stem blight [...] pathogen that causes gummy stem blight. Damage symptoms Mycosphaerella cucumis in cucumber causes brown lesions on the foot and higher up on the stem. On the

Downy mildew of Cucurbits

or surviving mycelium sporangia are formed, structures in which zoospores are produced. However, in downy mildews, sporangia often germinate directly and [...] the stomata or directly by penetrating the cuticula. For germination free water is required. For most downy mildews, the optimum temperature is around [...] density, good aeration during propagation and maintaining a warm and dry climate in greenhouses. Use hygiene measures. Start clean, remove crop residues and prevent

Rhizoctonia solani

onto the soil and thus increase the pathogen density in the soil for the next crop. The mycelium grows in a typical way, with branching at 90 degree angles [...] res. These spores don’t play a role in the epidemics or dispersal of the fungus, only the mycelium is important in this context. Thanatephorus cucumeris [...] soil-inhabiting fungus, that is very persistent in the soil. It overwinters as mycelium or sclerotia in the soil and on crop residues. It is also seed-borne

Crazy roots, hairy roots, crown gall

growth (crazy roots). In greenhouse vegetables, the roots overgrow the substrate and in severe epidemics the drippers get clogged. In tomato, excessive vegetative [...] 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 [...] gutters etc. Adjust the work order in greenhouses to fit with the hygiene protocol Disinfect the nutrient solution in order to prevent biofilm growth inside

Flowering potted plants

plants, the most common species are: Poinsettia is well known and popular for its large red, white and green leaves, especially around Christmas. Begonia [...] these species are usually grown indoors and are used as ornamental houseplants in countries with colder climates. Kalanchoe is a tropical, succulent flowering [...] species belonging to the family of Crassulaceae . Hibiscus is well known for its large, ornate flowers which are trumpet-shaped. These flowers have five

Flies

shore flies are mainly a problem in greenhouses. Their larvae live in the ground and prefer moist substrates that is rich in organic matter. Although they [...] fly larvae in the soil, while traps and attractants reduce adult populations and support monitoring. With Koppert’s biological solutions for flies, professional [...] Solutions for fly control Learn more about The adult form of the onion fly Delia antiqua What are flies? There are several flies that are pests in agriculture