Care urged when saving weather-damaged grain for seed
Growers planning to retain grain from the 2010 weather-affected harvest for sowing next season are urged to select, store and manage their seed with particular care and attention.
Heavy rain and flooding during harvest throughout parts of the southern cropping region have heightened the need for extra precautions when retaining seed for 2011’s cropping programs, according to industry authorities.
Grains Research and Development Corporation (GRDC) southern panel member and grains industry consultant, Dr Allan Mayfield, says it is vital that growers closely scrutinise the grain they intend to retain for sowing and keep a close eye on it over the coming months.
“Weather-damaged grain – that which has been subjected to wetting at harvest – is more susceptible to poor germination, low vigour and degradation during storage and handling,” Dr Mayfield said.
“For establishment of healthy crops next season, it is therefore important that growers implement a seed management strategy that begins at harvest and continues through storage, handling and seeding.”
To assist growers in determining whether grain is viable for sowing and what is an appropriate and effective seed management program, the GRDC has published a detailed Retaining Seed fact sheet.
The fact sheet will be distributed in the January/February edition of Ground Cover magazine, is accessible via www.grdc.com.au/GRDC_FS_Retainingseed
and is also available free (plus postage and handling) through GRDC’s Ground Cover Direct – freecall 1800 110044 or email firstname.lastname@example.org.
Dr Mayfield, who collaborated with other industry experts in developing the fact sheet, said all crops were susceptible to deterioration in seed quality during wet harvests.
“Mild symptoms can be a loose and wrinkled seed coat in some pulses, while more advanced symptoms can be seed staining, fungal mould and visible signs of germination,” he said.
“It is essential to recognise whether the damage is cosmetic or the symptom of a seedborne disease and if it will impact on germination.”
Dr Mayfield said that due to the vulnerability of canola’s small seed it was recommended that unless it was harvested before any weather damage it should not be retained for sowing. Irrespective of availability, hybrid canola seed should not be retained for seed as the crop will not be true to the original first generation (F1) seed.
Any retained seed should be graded and tested for germination and vigour. Testing for seed-borne disease is also recommended, especially with saved pulse seed.
Dr Mayfield said that knowing the germination percentage at harvest would help determine how much extra seed may be required for sowing.
“Assessing germination during storage will indicate potential problems, while a germination test prior to seeding will allow sowing rates to be adjusted.”
Other key points contained in the GRDC fact sheet that growers should consider when retaining grain for seed include:
• While a laboratory seed test should be used to establish the germination percentage of on-farm retained seed before sowing, especially if it has been weather damaged, a simple on-farm germination test can be done in soil. This will give a good indication of emergence and seedling vigour as at germination.
• Seed-borne disease generally cannot be identified from visual inspection so requires laboratory testing.
• Achieving and maintaining low temperature, humidity and grain moisture content for stored grain is even more critical if grain has been weather damaged. As weather damaged seed deteriorates faster than sound seed it should not be stored for more than 12 months.
• With many weedy pulse and cereal crops in a wet season, desiccation or crop topping often becomes necessary. Depending on timing and chemicals used, this could affect seed quality for sowing.
• Grain must not be retained for seed when glyphosate has been used in pre-harvest applications.
• Seedling emergence can be affected by sowing too deeply, cold or wet soil, some seed dressings and herbicides, and hard-setting soil.
• For more information contact Allan Mayfield on 0418 818 569 or grain storage expert Peter Botta from PCB Consulting on 0417 501 890
• GRDC Project Code: COR00019
• This media release and other media products are available via www.grdc.com.au/media
GRDC Project Code