Flash News
  • Factors that influence plant… We cannot control and know all the factors that influence plant growth. We know that by addressing the most limiting factor to plant growth, plants…
  • Sweet potato farming –… The sweet potato is an underrated popular vegetable in South Africa. Since it is a tropical crop, it cannot be grown everywhere. Interestingly, it is…
  • Sweet potato fertilizer application… Sweet potato fertilizer requirements can be calculated if you know your soil type and have a good idea of the yield potential of your land…
  • Soil Magnesium Soil magnesium is by no means unimportant. Nitrogen, potassium and phosphate research dominates that of soil magnesium. Calcium is hardly ever a problem in soil.…
  • Manure – a technical… Manure is the waste from animals. Farmer's source manure either from natural deposits or livestock farmers. The content of manure is highly variable, and each…
Facebook Twitter Google Plus Pinterest
Green beans

Virus diseases of green beans

Virus diseases of green beans

Virus diseases of green beans is a problem in the open field. As viruses cannot move by themselves, they need a host or vector to hitch a ride. Two main methods of transportation or distribution are insects and humans.  Insects are the most difficult to control and are also the most numerous, however, controlling human movement and hygiene can help reduce the spread of viruses throughout the field. Human control and hygiene should be the first step in disease management since it has very low cost.  The problem is controlling insects. You might have a good pest control plan in place, but if the one insect came through your barriers, it can spread the virus in a section of the field. These infected plants then infect other insects feeding on them, so the virus spreads again.  For that reason, virus control is so difficult and many seed companies are trying genetic methods for defence.

Bean mosaic virus

The margins and tips of leaves curl downwards.  The leaves show typical yellow-green mosaic. Dark green bands along the veins contrast against light green parts of the leaf.  Bean mosaic virus is seed borne. The only way to control the virus is to buy seed from reputable seed companies.

Yellow mosaic viruses

Symptoms are bright yellow spots between dark green coloured normal leaf tissue. Most of the leaves infected or malformed. This disease is a major problem and can cause significant crop losses.

Necrosis viruses

The necrosis viruses cause dwarfing of plants. The whole plant becomes necrotic or brown and dries out and dies.  It is a serious problem in some areas of production.


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.