Pythium and Phytophthora root rot in closed hydroponic systems
Diseases of crops grown and closed hydroponic systems can be a problem and occasionally catastrophic. However, the presence of a pathogen does not necessarily mean...
Category Archives: Diseases
Source of viruses in a greenhouse
Everyone has become more knowledgeable about the spread of viruses and the diseases they cause. Just like the COVID virus, we have to understand the...
The basic principles of a good spray program
Well planned spray programs are more effective than unplanned, random chemical applications. Have you ever considered spraying when there is no pests or diseases? Poorly...
Angular leaf spot
The disease is found in conditions if high humidity, especially in poor ventilated greenhouses or where the ventilation is not controlled properly. Optimum temperature for...
Basic pest and disease resistance management strategies in greenhouses
Resistance to chemicals is due to the intense selection pressure exerted on the population that is controlled. There is only a limited number of chemicals...
Downy mildew on lettuce
Downy mildew is a serious problem in greenhouses especially under cold humid conditions. It is caused by the casual organism Bremia lactucae. Of the commercial...
Sclerotinia or watery soft rot
Sclerotinia symptoms Leaves, especially the older ones, start to wilt during any stage of growth. The wilting continuous until the plant collapses completely. The...
Grey mould
Grey mould is found on lettuce, escarole, endive and globe artichoke. The disease is most important during transit of these crops. The disease is caused...
Septoria leaf spot a destructive tomato disease
Septoria leaf spot is one of the most destructive diseases on tomato and is caused by Septoria lycopersici. It is most destructive during moderate temperatures...
Anthracnose can cause serious losses in tomatoes and lettuce
Anthracnose is caused by the fungus Colletotrichum phomoides and is a common and widely distributed rot of ripe tomatoes. The disease can cause serious losses...
Bacterial spot causes injury to seedlings and adult plants
Bacterial spot is caused by Xanthomonas vesicatoria and is most noticeable in its effect on fruit. However it may also cause considerable injury to the...
Fusarium wilt
Fusarium wilt (Fusarium oxysporum) is one of the most damaging fungi that infects tomatoes. Fusarium wilt is a soil borne disease and infects both soil...
Verticillium wilt – Verticillium alboatrum – found on all vegetable crops
Verticillium wilt is caused by the fungus Verticillium alboatrum. Quite often verticillium wilt is confused with fusarium wilt. The fungus attacks a wide range of...
Damping-off affects almost all seedlings
Most seedlings are particularly susceptible to damping-off. In general the disease is caused by the fungi Pythium but some damage also occurs from infection from Rhizoctonia...
Bacterial wilt
Bacterial wilt known as Ralstonia solanacearum biovar 3, formerly known as Pseudomonas solanacearum (SMITH) and Burkholderia solanacearum). Bacterial Wilt also known as Southern bacterial wilt...
