Managing bean root and stem diseases

Abstract

This project “The management of bean root and stem diseases” (VG03002) was to provide an update on the current diseases of green beans in Australia and to investigate management options for soil borne diseases. The collaborative project was carried out in New South Wales, Tasmania and Queensland.

Beans can be affected by a number of diseases. Soil borne organisms initiate establishment diseases and stem rots that can be serious in certain bean growing areas. Their damage results in large areas either not germinating or damage at a later growth stage. Many of these organisms can survive for long periods in soils, in plant material or on volunteer weeds or alternate crops.

This project commenced in January 2004. The aim was to investigate disease problems currently associated with beans especially those that contribute to stem and root rots. Earlier work identified a disease affecting beans on the north coast of NSW as Aphanomyces root rot (ARR). A fungicide was found that controlled the disease but soon after the product was removed from sale. Since then, large crop losses continue to occur. Management of this fungus is a priority and had not been examined thoroughly. Avoiding land that has grown beans for up to ten years is the only control option for ARR. Its occurrence in other growing regions had not been fully investigated.