American Bollworm
Bollworm description Bollworm, also known as tomato fruit worm or American Bollworm, Helicoverpa armigera, are small caterpillars (about 30mm long, slightly more than 1 inch)...
Common physiological disorders in cucumbers
Physiological disorders caused by low temperatures Low temperatures injury only occurs with fruit that are in storage (either in transit or in storage rooms). Small...
Pruning cucumbers in greenhouses
Selecting a cucumber pruning system The question arises which system should be used. Each system has its advantages and disadvantages according to the ability and...
Sweet potato whitefly
Sweet potato whitefly description Sweet potato whitefly (Bemisia tabaci, order Hemiptera and family Aleyrodidae) is a sap feeder. The adults are about 4-5mm long with...
Red spider mite
Red spider mite description Red spider mite, of the genus Tetranychus urticae, are sap feeders. Although there are several species of spider mites which attack...
Green bean fertigation – a delicate matter
Green bean fertigation must be controlled carefully since they are extremely fast growing. There are pro’s and con’s of fast growing crops. An advantage can...
Leaf hopper
Leaf hopper description Leaf hoppers are usually less then 13mm in length, with long slender tapered bodies. They tend to be pale green to tan...
Leaf miner
Leaf miner description The adult leaf miner (Liriomyza sativae) is a 1-1.8mm long shiny black fly with a prominent yellow triangle between the bases of...
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...
Whiteflies in greenhouses
Description of whiteflies Whiteflies are about 1.5mm long, the adult is white which resembles a tiny moth. They produce oblong eggs, pale green to purple...
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...