Some barley varieties are known to be more susceptible to head loss, lodging, sprouting and brackling and consequently, delaying harvest in these paddocks can have a negative impact on grain yield.
BCG research undertaken in 2013 found that delaying the harvest of some barley varieties decreased yields by up to 0.3t/ha.
Through the GRDC-funded barley agronomy initiative, this research is being expanded on this year with a replicated field trial grown at Horsham in Victoria’s central Wimmera.
BCG’s 2013 investigation revealed significant differences between 13 commonly grown varieties in terms of head loss, lodging and yield when harvest was delayed by six weeks (December 17 as opposed to the optimum time of November 6).
The varieties compared included Gairdner, Hindmarsh, GrangeR, Bass, Commmander, SY Rattler, Scope CL, Fathom, Fairview, La Trobe, Navigator, Skipper and Compass.
This trial confirmed that Scope CL and Gairdner should be a priority at harvest time as they are particularly susceptible to head loss when harvest is delayed. When harvested at the optimum time, head loss numbers were low (averaging three heads/m2) and differences between varieties were insignificant.
In terms of lodging, Scope CL and Skipper suffered the greatest when harvest was delayed while Bass, Navigator, Gairdner and GrangeR stood up extremely well (less than 10 per cent lodging).
Given the small rain events experienced last harvest (22mm between the two harvest dates), it was concluded that delayed harvest, rather than rainfall damage, contributed to the high head loss and lodging rates in some varieties. Consequently, BCG recommended growers prioritise varieties susceptible to these risks at harvest time.
The findings from an economic analysis carried out on this research trial showed that although commonly grown high yielding varieties such Scope CL and Gairdner are more susceptible to head loss (and lodging in Scope CL), it is still more profitable to keep these varieties in the rotation over poorer yielding alternatives that are less susceptible but may produce lower yields. The key is to manage the risk.
Given the unpredictability of seasons, a good risk management strategy is to opt for a high yielding variety that is well adapted to a wide harvesting window. Also, consider variety ratings for lodging, maturity height and head retention.
