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Bean Rust



P_beanrust

Bean Rust

Usually appear in

Spring and summer


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Caused By:-     The Fungus Uromyces appendiculatus

Description

Rust on Phaseolus Genus of beans which include beans Bush bean, French bean, Kidney bean, Pinto bean, Pole bean, Runner bean, Snap bean is caused by the fungus Uromyces appendiculatus. This fungus is unrelated to Broad Bean rust which is caused by the fungus Uromyces viciae-fabae and infects Vicia beans which include Bell Bean or Tic Bean, Broad Bean, Fava Bean, Field Bean.
Rust fungi are described as biotrophs which means that they grow within the living tissues of the plant and extract nutrients from the cells. Although they do not kill the tissues rapidly – heavy attacks by rusts can cause tissues to collapse and die prematurely.
Most rusts require two different plant hosts in order to complete their life cycle, but both on bean seem to only have a single host.
This disease occurs occasionally under prolonged periods of warm, moist weather and exists in many pathotypes causing different
Initially, pale, raised spots appear on the upper leaf surface, corresponding to small white pustules on the lower surface of French and runner beans. They are often surrounded by a yellow halo. Severely infected leaves whither and die and cropping is reduced. The pods and stems can also be affected. Later, dark brown resting spores form within pustules which survive between crop cycles to infect new crops.
Picture from Wikimedia Commons.
See also these other rusts Anemone, Antirrhinum, Bluebell, Broad Bean, Cedar Quince, Chrysanthemum White, Fucshia, Gladiolus, Gooseberry, Hollyhock, Juniper Pear, Mahonia, Mint, Pear Juniper, Pelargonium, Periwinkle, Plum, Potato Internal, Quince, Rhododendron, Rose, Rust, White.


Control

As with any fungal disease one of the best ways of preventing it is by good hygiene. Remove all dead leaves in autumn to prevent the spores from over wintering. If the leaves is from an infected plant burn them.
Check plants regularly and remove infected leaves by hand as soon as they are seen and then spray with a suitable fungicide. Spray the plant and the soil around it with a fungicide suitable for the control of rust fungus.
Water the compost of susceptible plants directly trying not to wet the foliage as the rust needs a period of leaf wetness to germinate and infect.
Maintain an open structure to allow good air circulation through the plant and ensure greenhouses are always well ventilated.
Rotate bean with non-host crops.
Disinfect reusable poles in bean production.
Often there are resistant varieties of the plant you wish to grow.
Avoid over application of nitrogen, which produces soft growth which is more susceptible and ensure adequate potassium fertilisation.



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