South Perth, Western Australia
February 15, 2007
Selecting the best seeding
time to avoid high disease pressure is pivotal in managing
blackleg disease in canola according to latest research from the
Department of Agriculture
and Food, Western Australia.
The research and recent trial results will be outlined today at
the Department’s annual Crop Updates, presented by researchers
Ravjit Khangura, Moin Salam and Bill MacLeod.
Dr Khangura said the research, funded by the
Grains Research and Development
Corporation, was aimed at improving blackleg management
strategies through better understanding of blackleg and its
environment interactions.
She said the work included experiments to determine the dynamics
of susceptibility to blackleg crown canker in canola.
“Results confirmed the three key elements in blackleg management
were the use of resistant varieties, reducing the exposure to
spore showers during the susceptible period and use of
appropriate fungicide application,” Dr Khangura said.
“Avoidance of peak ascospore shower activity in young canola
through manipulation of the sowing date is critical to reducing
the risk of severe blackleg.
“However, we also found that canola was more susceptible to
blackleg up to the 6-leaf stage, but the length of this
susceptibility window could vary in different regions and with
different sowing times.
“For example a crop sown during the end of May to mid June may
remain susceptible for up to 10 weeks of more compared with
crops sown during the early to mid May period.
“Therefore, fungicide protection from blackleg in high disease
pressure situations, and particularly for late sown crops, could
be required for longer periods for moderately susceptible to
moderately resistant varieties.”
Dr Khangura said the development of the Blackleg Sporacle model
had been a significant leap towards defining regional risk of
blackleg through predicting the onset of blackleg spore showers.
“However, it is important to investigate the role of seasonal
conditions in the development of blackleg and yield losses,” Dr
Khangura said.
“Future blackleg models, forecasting regional disease dynamics
and its impact on yield, may help growers better understand
blackleg risks, and assist them in applying cost effective
strategies to manage the disease.” |
|
