Prolonged wet and cool harvest conditions across many parts of Australia’s grain growing regions could produce headaches for growers long after the crops finally come off.
Adverse weather over recent weeks has not only delayed harvest for many growers but it has created potential for issues.
The unusual combination of damp conditions, high-yielding and high biomass crops, and wind and hail damage is likely to have implications for stored grain, retained seed, stubble management, weeds and pests.
Growers will need to be vigilant in minimising potential flow-on issues.
Rain has caused concerns with falling numbers at receival sites, predominantly in early sown cereals.
Falling numbers often occurs without visual indication and is a sign that the germination process has started in grain. The process is caused by alpha amylase enzyme activity reducing starch to sugar and causing the falling number measure to decline.
Retaining weather-damaged seed
Wet conditions prior to or during harvest can cause seed to germinate which reduces starch and protein and results in downgrading of grain quality.
It can also affect germination for grain kept for next season, potentially hampering future crops.
Growers should have weather-damaged grain tested for viability and vigor before sowing next season, to confirm accurate sowing rates of partially germinated seed and detect seed-borne diseases.
Seed testing is a relatively minor cost that can offset future losses as a result of not sowing seed at the optimum density.
Grain subjected to adverse weather conditions at harvest and being stored on-farm should be monitored regularly.
Storing cereals and pulses with an average moisture content above 12.5 per cent can cause a range of issues, including mould and insect outbreaks in storage facilities.
GRDC grain storage specialist Ben White says successful on-farm storage this season may require aeration cooling.
Mr White says aeration cooling enables growers to store slightly over-moist grain for up to three to four weeks before it is dried or blended with dry loads.
Weather damaged seed deteriorates quicker than sound seed in storage. But storing at lower moisture and reduced temperatures with aeration cooling can assist in maintaining seed viability.
Heavy stubble loads are likely to present growers with challenges ahead of next year’s seeding programs. Growers are urged to factor stubble management into their post-harvest activities.
Wheel track damage
Wheel tracks across the north have been significantly impacted by continuous wet conditions. Controlled traffic farming enterprises are advised to investigate renovation options.
Other potential issues following this year’s harvest include a build-up in mouse populations promoted by high levels of grain left on the ground, as well as a green bridge of weeds and volunteer crops which could harbour diseases and invertebrate pests.