Apple collar rot

infection is either by germinating sporangia or by zoospores produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required [...] black discolouration of the roots. On the foot, dark brown lesions with sharp borders occur. Above the graft and on leaves, dark brown, irregular lesions [...] General Phytophthora cactorum is a plant pathogen that causes root rot, rhizome rot of strawberry, apple rot, apple collar rot and crown rot. It has an

Pierce's disease of grapevine

General Xylella fastidiosa is a gram-negative bacterium which is limited to xylem tissue. It has many hosts, many of which show minor or no symptoms. More [...] In peach, the canopy of infected plants is compact and umbrella-like due to the shorter internodes. The foliage is denser and the leaves are a darker green [...] smaller and their sugar content is higher. The early blossoming and fruit set in peach does not occur in citrus, there is no difference between infected

Aphidius ervi

Aphidius ervi is available in a bottle ( Ervipar ). Spread the material on rock wool slabs or in Diboxes Make sure the material remains dry and is not moved [...] period when aphid infestation is expected. Consult a Koppert advisor or a recognized distributor of Koppert products for advice on the best strategy for your [...] ervi The parasitic wasp Aphidius ervi is most effective between 20 and 25°C (68 and 77°F). This natural enemy is not effective at temperatures above 30°C/86°F

Early blight

only known stage in all Alternaria species is the asexual stage. Conidia and mycelium overwinter in the soil and on crop residues and cause primary infection [...] veins. Lesions can easily rupture. Other symptoms are brown lesions on stem and foot. On fruits, dark sunken, leathery lesions occur at the side of the stem [...] blight of potato and early blight of tomato, which presents itself as spots on leaves, petals and stems. These spots can be distinguished by the dark and

Grapevine powdery mildew

critical for effective control strategies. Powdery mildew on grapevine leaves. White, powdery spots on the leaf surface. Signs and damage symptoms of Grapevine [...] to yellowish spots on the upper leaf surface Development of white to grey, powdery fungal growth Powdery coating may also appear on the underside of leaves [...] (Erysiphe necator) is closely synchronized with the vine growth stages and environmental conditions. Understanding its lifecycle is essential to implementing

Blight of pepper

infection is either by germinating sporangia or by zoospores produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required [...] General Phytophthora capsici is an oomycete plant pathogen that causes blight and fruit rot of peppers and other important commercial crops. Damage symptoms [...] 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 and

Greenhouse whitefly

es: If the population is very large, feeding on plant sap can affect the physiology of the plant, as a result of which growth is retarded. In full sunlight [...] and the excess is excreted as honeydew, with larger larvae expelling large quantities. The damage that whiteflies cause to a crop is the result of sucking [...] The honeydew deposited on fruit makes it sticky. Dirt adheres to the fruit, and the growth of sooty moulds ( Cladosporium spp .) is encouraged, making it

Black rot of carrots

only known stage in all Alternaria species is the asexual stage. Conidia and mycelium overwinter in the soil and on crop residues and cause primary infection [...] radicina ) causes death of seedlings and dark brown lesions with a yellow halo on leaves, growing into crown rot. Infection of carrots during post-harvest storage [...] storage causes dry, sunken, black lesions. Typically, Alternaria causes spots on leaves, petals and stems. These spots can be distinguished by the dark and

Beet armyworm

ability to develop on wild vegetation during the summer. It is highly polyphagous, feeding on plants of more than 20 families. It is a serious pest in [...] worst damage is caused by attacks on flowers and buds. Life cycle and appearance of Beet armyworm The beet armyworm (Spodoptera exigua) is a small, nondescript [...] and a yellow band running the length of the body on either side, above which there is a black dot on each segment. The young caterpillars live in groups

Tobacco whitefly

es: If the population is very large, feeding on plant sap can affect the physiology of the plant, as a result of which growth is retarded. In full sunlight [...] referred to as ‘pupa’ although strictly spoken this is not true) and adult. The larvae are found on the underside of young leaves and have an oval shape [...] often scattered over the entire plant where they deposit their eggs. This is why on one leaf all different developmental stages can be found together. When