Scrutinise seed for sowing this year
Grain grower and Mallee agronomic consultant Kate Wilson has warned heavy summer rain through parts of the southern cropping region could affect the viability of grain that growers are planning to retain for sowing in 2017.
Mrs Wilson said any grain subjected to wetting at harvest was more susceptible to poor germination, low vigour and degradation during storage and handling.
The Grains Research and Development Corporation, GRDC, Southern Regional Panel member said growers should closely scrutinise seed being set aside for planting.
Mrs Wilson said it was essential growers determined whether damage to grain caused by rain at harvest was purely cosmetic or the symptom of a seed-borne disease which would affect germination.
“To ensure establishment of a healthy crop next season, it is important to pay particular attention to the seed that is being saved for sowing,” she said.
“Proper management of the seed starts at harvest and should continue right through to storage, handling and seeding next year.”
Mrs Wilson said growers should also be aware some cereal varieties were more susceptible to the effects of late season weather damage.
“For example, the imidazolinone-tolerant Kord CL Plus wheat is rated as being susceptible to pre-harvest sprouting,” she said.
She said the GRDC offered a detailed retaining seed fact sheet to help growers to determine whether grain was viable for sowing and what was an appropriate and effective seed management program.
The fact sheet, which can be viewed and downloaded at www.grdc.com.au/grdc-fs-retainingseed, shows the symptoms of seed quality deterioration can range from mild, such as a loose and wrinkled seed coat in some pulses, to more advanced, such as seed staining, fungal mould and visible signs of germination.
“Unless canola seed was harvested before any weather damage, it should not be retained for sowing due to the vulnerability of canola’s small seed,” Mrs Wilson said.
“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.”
Other points contained in the GRDC fact sheet 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.