Why optimal flowering periods?
• Autumn rainfall decline (Cai et al. 2012)
• At least partly attributable to anthropogenic climate change (Cai et al. 2013) and results in the systems which bring the ‘autumn break’ to SE Australia being less frequent (Pook et al. 2006, 2009)
• Sowing dates required for current cultivars to achieve optimal flowering periods coincide with marked rainfall decline which has regionally reduced yield
• In addition, > farm size and > extreme spring weather
• Farmers need new cultivar x management strategies to stabilise flowering time
3. Why optimal flowering periods?
• Autumn rainfall decline (Cai et al. 2012)
• At least partly attributable to anthropogenic climate change (Cai et al.
2013) and results in the systems which bring the ‘autumn break’ to SE
Australia being less frequent (Pook et al. 2006, 2009)
• Sowing dates required for current cultivars to achieve optimal flowering
periods coincide with marked rainfall decline which has regionally
reduced yield
• In addition, > farm size and > extreme spring weather
• Farmers need new cultivar x management strategies to stabilise
flowering time
3 | Optimal flowering periods| Bonnie Flohr
4. Wheat’s optimal flowering period (OFP)
4 |
• Water stress
• Heat stress
• Frost
• Disease
• Inadequate
growth
OFP
• Critical for yield
• A compromise of all
factors
• Highest yields come
with ~5‐10% frost
damage
Optimal flowering periods| Bonnie Flohr
16. Fast winter wheat: RAC2341
• RAC2341‐ AGT Roseworthy breeding program
– vav x avv
• 70% Mace
• Responds to vernalisation
– Requires cold temperature accumulation to initiate flowering, fast‐spring
wheats have a low requirement
• Fast to develop once vernalised
• 4 x experimental sites in GRDC early sowing project‐ James Hunt
16 | Optimal flowering periods| Bonnie Flohr