Pea stubble from the previous season can harbour sexual ascospores from the fungus D. pinodes. Wind and rain can carry the sexual ascospores into the new season's crop and cause the establishment of an early infection.
Summer and autumn conditions determine when blackspot spores are released. Sowing of field pea crops should be delayed until approximately 60% of blackspot spores have been released.
Potential yield losses from blackspot can be avoided by:
- sowing field peas at least 500 m from previous season's pea stubble
- sowing in paddocks where field peas have not been grown in the last 3 years
- sowing crops after 60% of spores have been released to reduce the disease severity.
Blackspot Manager
The Blackspot Manager is a location and season specific weekly forecast model that predicts the maturity and release of spores using data from the nearest weather station.
Where paddock rainfall is less than indicated by the nearest weather station, the probability of severe black spot may be higher. Predictions are based on the assumption that the location receives at least one rainfall event in excess of 3.5 mm weekly.
The forecast accounts for varietal resistance and chemical options, agronomic yield potentials, agronomic constraints (frost and terminal drought), risks of spore showers, disease severity and disease related yield loss. It then weighs agronomic yield loss and disease yield loss and suggests a window of sowing dates.
Subscribe to Blackspot Manager
Subscribe to the free blackspot email or SMS alert service.
Use the subject title: Blackspot and include your name and the nearest weather station. Text these details to 0475 959 932 or email Blackspot Manager.
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