By Mark McLean (Department of Economic Development) and Stuart McColl (BCG)
- SFNB caused yield losses of 0.2-0.3t/ha in very susceptible barley varieties at Quambatook during 2014.
- SFNB increased screenings by up to seven per cent and reduced retention by up to 13 per cent in very susceptible varieties.
- Avoid growing very susceptible and susceptible rated barley varieties to reduce the risk of grain yield and quality loss due to SFNB.
Spot form of net blotch (SFNB) has been shown to reduce grain yield (0-25%), increase screenings (5%), reduce retention (13%) and grain weight (6%) in the Wimmera region of Victoria (DED Vic unpublished data). During six years of study, losses have varied in response to seasonal conditions, with greater losses experienced during seasons with average or above average rainfall during the winter and spring months. Losses were uncommon during seasons with dry August and spring months.
DEDJTR and BCG conducted a trial at Quambatook during 2014 as part of the GRDC
funded project DAV00129. The experiment compared grain yield and quality loss
in eight barley varieties with different susceptibility ratings to SFNB.
The trial showed that SFNB severity varied between the eight barley varieties, increasing according to higher susceptibility ratings. Infection levels fluctuated throughout the season, being more severe earlier (GS33) in response to wet conditions. Most of the infection was present on the lower leaves, as there were few rainfall events after flag emergence.