Stay ahead of pulse crop diseases
Date: 26 Oct 2016
South Australian pulse growers are advised to stay one step ahead of diseases which are being favoured by wet soils and warmer temperatures.
Chocolate spot and botrytis grey mould (BGM) diseases are spreading in faba beans, lentils and other pulse crops, according to South Australian Research and Development Institute (SARDI*) pulse research scientist, Dr Jenny Davidson.
Dr Davidson, whose research into pulse diseases is supported by the Grains Research and Development Corporation (GRDC), says high infection rates and disease spread will continue even when it is not raining as heavy canopies will draw humidity from wet soils.
She advises that fungicide sprays for chocolate spot in faba beans should be applied at approximately 14 day intervals in all varieties.
“Flowers are especially at risk of infection, leading to flower loss, and pod infection and seed abortion can also occur if crops are left untreated,” Dr Davidson says.
Lentil varieties rated moderately resistant to moderately susceptible (MR-MS) to BGM may require fortnightly sprays to control the disease, while varieties with resistant (R) ratings may require sprays at three to four weekly intervals as the current seasonal conditions can overcome their resistance.
Dr Davidson says chickpeas do not normally become infected with BGM in SA but in current conditions this could occur, leading to flower loss, pod infection and seed abortion.
“Fungicides to protect against BGM could be an advantage in chickpeas this year,” she says.
Ascochyta blight will continue to spread during rainfall and therefore all pulse crops may require fungicide sprays to control this disease, timed ahead of rain events.
“In particular, crops that are podding will be most susceptible, and fungicide sprays to protect pods are essential ahead of rain to prevent pod infection, seed staining and seed abortion,” Dr Davidson says.
“Growers are reminded that all chickpea varieties in SA are now considered moderately susceptible to susceptible to this disease, with the recent loss of resistances.
“All cultivars will need protective sprays, and crops that are infected will require fortnightly sprays while it continues to rain. When rain ceases, the fungicide sprays for ascochyta blight can also stop.”
Dr Davidson encourages growers to inform SARDI of any anomalies in cultivar reactions to ascochyta blight. Dr Davidson can be contacted by phoning 08 8303 9389 or emailing email@example.com.
* SARDI is a division of Primary Industries and Regions SA (PIRSA).
Rob Johnson, Communications Adviser, SARDI
0423 292 867
Sharon Watt, Porter Novelli