Dry seasonal conditions have resulted in small and shrivelled grain being harvested in regions of New South Wales this season, and growers are reminded of some rules of thumb to adhere to when retaining seed following a tough year.

This grain can be susceptible to poor germination and low vigour (ability to push through the soil following germination) so extra care is needed and planting rates in 2020 may need to be adjusted.

Frost may have also affected grains in some areas, causing a lower hectolitre weight and higher screenings - the material that is removed when grain is cleaned.

GRDC Grower Relations Manager - North, Richard Holzknecht said retaining seed for next season was a priority for many growers given concerns about supply and minimising costs for 2020.

He advised growers to retain seed from their cleanest paddocks from both a weeds and seed purity standpoint.

"If you are grading cereal seed, take the largest seed size possible to get the required amount for seeding."

Department of Primary Industries (DPI) research and development agronomist Rohan Brill said when it came to retaining canola seed growers should target a diameter of 2mm.

"Ideally harvest seed at low moisture and store in a cool dry location and importantly ensure that seed is protected from insects over summer," Mr Brill said.

"If seed is known to be of low quality, avoid fungicides that can reduce coleoptile length of cereals (e.g. triadimenol) and hypocotyl length of canola (e.g. fluquinconazole).

"Don't retain seed from paddocks that have been spray-topped with glyphosate. Check the quality of carry over seed that was intended to be sown in 2019 as quality will degrade over time."

Mr Holzknecht said that while a laboratory seed test for germination and vigour should be carried out before planting, growers could also conduct a simple on-farm test after harvest to ensure they retained enough viable seed and again before planting to achieve acceptable plant populations the following season.

"This on-farm test involves collecting and counting seed from each lot to be planted, putting the seed between moist paper towels placed in a sealed plastic bag, leaving them for five to seven days in a warm place and then calculating the germination percentage after counting the number of seeds that have not germinated," he said.

"Germination and vigour are not always closely correlated so growers should consider lab testing where needed.

"Grower to grower trading is also allowed for some wheat and barley varieties so purchasing seed from another region may be a better option that sowing your own seed."

Information about factors affecting grain crop seed germination and effective storage are also available on the GRDC Stored Grain Information Hub.

The GRDC Stored Grain Information Hub states that if on-farm tests reveal poor germination rates, growers could decide to pay to buy in seed, but if rates were satisfactory, test results could be used to guide how much extra seed to keep.

Factors influencing how much seed needs to be retained for sowing include:

• Screen grain before storage for seed size and remove foreign objects.
• Germination test retained seed for sowing as soon as possible after grading.
• Store sufficient seed to allow for seeds that germinate but don't emerge.
• Record seed weight (grams per 1000 seeds) for sowing rate calculations.
• Retain sufficient seed volumes to allow for change of plans in planting area and germination loss during storage.
• Re-test prior to sowing as further decline in germination can occur during storage.

Once seed had been graded at harvest, correct storage is then needed to ensure the viability of seed for the following season.

This includes ensuring storage temperatures are cool, using aeration in the silo and making sure the seed has low grain moisture content.

Monthly monitoring of the stored seed for storage pests is advised, following up with prompt fumigation if any pests are detected. Minimising seed handling, especially augering fragile pulse seeds is also recommended.

More information about correct storage for retained seed is available in a GRDC Storing planting seed video and information about frost damaged crop salvage options and seed retention is available in a GRDC podcast.

The GRDC Updates paper Testing of farm-retained and carryover seed also contains information and stresses that while seed is a relatively low-cost input on a per hectare basis, it is essential in setting up a paddock for profit or loss.