WITH improved conditions in some areas of central, southern and northern New South Wales, growers keen to ensure crops remain vigorous and healthy have been advised to get the correct diagnosis before spraying fungicide.
Continuing wet weather has been great for winter cereal production this season, but it has also provided ideal conditions for leaf diseases such as stripe rust, yellow spot and net blotches.
NSW Department of Primary Industries (DPI) senior research scientist Dr Steven Simpfendorfer said agronomists and growers should monitor crops for potential appearance of leaf diseases and check the underlying cause of discoloured leaves.
“Already stripe rust has been reported to DPI pathologists in early sown wheat crops near Young, Forbes and Boggabri,” Dr Simpfendorfer said.
Samples analysed and confirmed as stripe rust have been submitted to the Australian Cereal Rust Control Program to assist with early detection of potential new pathotypes and monitoring of disease spread.
Dr Simpfendorfer said the key considerations to effective fungicide application in cereals were correct identification of the disease, level of resistance in a variety, level of disease in the crop, growth stage and current plus predicted weather conditions.
“Not every discolouration on wheat or barley leaves is related to disease, with underlying nutrition, herbicide and frost issues now also appearing in crops – fungicide will not fix these issues,” he said.
“Growers need to consider the availability of fungicide for the whole season.”
Source: NSW DPI
Variety resistance ratings available in the NSW DPI Winter crop variety sowing guide 2020 provide growers with valuable information. For example, wheat varieties rated MR or MRMS for stripe rust do not need fungicide protection for this disease.
NSW DPI pathologists can assist with what may be a challenging, but ultimately rewarding season and growers are advised to discuss fungicide strategies with their agronomists.
NSW DPI can assist with ensuring correct diagnosis so growers can rapidly rule out if the leaf symptoms are not related to disease and avoid unnecessary application of fungicides.
Growers can send a clear photo to Dr Steven Simpfendorfer on 0439581672 or email Dr Andrew Milgate [email protected]
Information on winter crop diseases is available on the DPI website https://www.dpi.nsw.gov.au/agriculture/broadacre-crops/winter-crops