June 22, 2003

Botrytis grey mould (BGM) is the next challenge in chickpea disease management in the northern grains region.

It is a major part of a continuation of a three year Grains Research & Development Corporation (GRDC) supported project based at New South Wales Agriculture's Tamworth Agriculture Institute.

The project, led by senior plant pathologist Kevin Moore, successful developed a disease management package for chickpea Ascochyta blight and plans to use that package as a model for BGM.

"In spite of the publicity that Ascochyta received following its outbreak in 1998, many growers and agronomists believe BGM caused greater losses in yield and seed quality in that and the following season," Dr Moore said. .

"Because the same conditions that favour BGM ­ warm, humid, high biomass ­ also favour high yield, it is important growers are able to capture the good seasons without losses from BGM.

"Ascochyta isn¹t being forgotten, however. Its management package will be refined ­ with trials to see whether new chickpea varieties and emerging breeders' lines with greater resistance need all the fungicide treatments recommended for older varieties.

"The Ascochyta package developed in our earlier research has been widely accepted by the industry, and has contributed significantly to the expansion of the chickpea area in the north.

"However we need to know whether the newer, less Ascochyta susceptible varieties coming out of the national breeding program require the rigorous fungicide regime currently recommended. Fungicide trials last winter also gave some perplexing results and we need to go further into that."

Dr Moore's team will also conduct field trials and survey commercial crops of chickpeas and faba beans for viruses such as beet western yellows virus, bean yellow mosaic virus, bean leaf roll virus, cucumber mosaic virus and chickpea chlorotic dwarf virus.

This work complements other virus research being addressed in separate GRDC projects.

He said the challenge with the planned virus research was that the situation in northern NSW and Queensland was dynamic, reflecting shifts in vector populations and proximity to virus reservoirs.

In some seasons ­ like 2002 ­ virus problems were minor, while in others ­ 2000 for example ­ entire crops were threatened.

Earlier research in the GRDC project had identified some key elements that might determine virus incidence.

The survey will involve a simultaneous survey for Sclerotinia, in a scoping study to identify how important Sclerotinia diseases are in northern farming systems.

Sclerotinia attacks a wide range of plants and Dr Moore's survey team may extend their quest to canola crops in the major agronomy zones.

"Growers around Walgett have expressed concern at the damage potential of Sclerotinia and our own project work and anecdotal evidence from agronomists suggest that it is an emerging issue in the northern region," Dr Moore said.

"But overall we don¹t know how important Sclerotinia is and where it occurs. The scoping study should answer those questions."