Phytophthora blight

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 [...] optimal for crop growth. Phytophthora overwinters in roots, infected tubers and bulbs or in the soil in different stages: as oospores (sexual overwintering [...] produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required. Dispersal is by wind and rain causes the pathogen to be returned

Shore fly

feed on green algae. However, they can transmit plant diseases and can be a nuisance to greenhouse works by their sheer numbers. Frass deposited on leaves [...] often in the vicinity of water. They feed on algae. Other shore fly species have diverse feeding habits but the larvae of most species feed on rotting [...] leaves or flowers in ornamental crops, lettuce and herbs also causes cosmetic damage, and sometimes this can occur on such a scale that growth, particularly

Hemispherical scale

depends on the host plant and can vary from 2 to 4.5 mm. The young nymphs are white to yellowish, more oval in form and with a raised H-pattern on the dorsal [...] occurs widely in tropical regions and in greenhouses throughout the world. It is a severe pest in coffee and citrus. Many ornamental crops can also be affected [...] symptoms The scales present are usually quite easy to see as shiny brown domes on leaf undersides close to the midribs. They produce large amounts of honeydew

Pea leaf miner

cosmetic damage. In tropical and subtropical areas this can lead to burning in fruit such as tomato and melon. Loss of leaves also reduces yield. In full-grown [...] across the world. This species can be particularly damaging to leaf vegetables and causes problems especially in lettuce grown on open ground. Damage symptoms [...] ground to pupate. A small percentage of the larvae remain hanging on the leaf and pupate there, sometimes on the upper surface but more commonly on the underside

Impatiens thrips

development from egg to adult on the plant, specifically on the leaves. Eggs are deposited in the leaf tissue, while subsequent stages are found on the upper- and [...] Pupation occurs on the leaf rather than on the ground. The prepupae and pupae remain immobile on the leaf tissue. Adults are found on both upper- and [...] serious the leaves themselves can shrivel. Echinothrips americanus is often found low in the crop. In sweet pepper the damage can be seen as discolouration

Mycotal - Effective at lower temperatures

inactive, they will start to build up a population as soon as the conditions are favourable. This can become a serious threat to you crop in a later stage. Therefor [...] Therefor it’s crucial to eliminate pests in wintertime, when pest pressure is still low. In this way you start the new season in a clean way, giving your [...] temperatures drop Even in the midst of winter, pests can be present in your greenhouse. Although the pest reproduction might be low in colder conditions, or

Bacterial soft rot, bacterial stem rot

population densities. It can survive as epiphytic bacteria on various plants or in the soil in low densities. It has also been found in the gut of insects, [...] cannot infect healthy green leaves, but can grow in senescent leaves and from there grow through the petiole to the main stem through the xylem vessels [...] um carovora can also be found as secondary pathogen in plants that are infected by other pathogens. The bacteria that causes black leg in potato is a different

Angular leaf spot

bacterium is very resistant to desiccation and can survive well in dry leaves or leaves in the soil, but not independantly in the soil. Under humid conditions [...] overwinters in plants and dead leaves, that become the primary source of infection in the spring. The bacteria are also introduced in a crop in new transplants [...] found in strawberry. Damage symptoms Xanthomonas fragariae initially causes small, water-soaked lesions on the underside of the leaf. They enlarge to angular

Fusarium head blight or scab

produce ascospores. In general, most Fusarium specieshave a similar life cycle. Fusarium overwinters for many years in the soil and on crop residues of infected [...] species. Fusarium is widespread and can infect a range of host crops. Many species are considered weak pathogens and can only infect wounded or stressed host [...] older, lower leaves. The spores are dispersed upwards to the ears by splashing rain drops or wind. On the infected ears, the typical pink spores are produced

Adalia bipunctata

elongated ovals. They can vary in color from pale yellow to light brown depending on environmental conditions. Pupae are often found attached to plant surfaces [...] Adalia bipunctata feeds on all aphid species, but the product Aphidalia is especially designed for the control of aphids in trees. How to use Adalia bipunctata [...] stages can be identified: Egg stage: Adalia bipunctata eggs are very small, elongated, and yellowish orange in color. They are typically laid in clusters