Australian Mungbean Association
Australian-grown mungbeans have quality written all over them!
Test your carryover seed early
Germination test. Photo: Ken Cunliffe, AgEtal Agricultural Testing Laboratory.
15 November, 2018
Any mungbean seed retained on farm from a previous crop should be tested well before planting to check the seed’s viability. Department of Agriculture and Fisheries’ grain storage specialist Phillip Burrill, recommends early testing so growers have time to seek out another suitable seed source if the test result from the lab indicates poor germination or vigour of the retained seed.
One of the laboratories that has the required expertise to test mungbean seed is AgEtal in Toowoomba. Director Ken Cunliffe said that seed testing is the best way to avoid lost productivity, and even complete crop failure, that will result from planting poor quality seed.
“Growers should only contemplate planting seed that has been stored in cool dry conditions, has proven germination and vigour and comes from paddocks free from seed borne diseases,” he said.
“The first step to proving seed quality is correct sampling. To have a representative sample for testing, collect small sub-samples for each seed lot from around 30 different positions – from different bags or different places in the silo – making a combined minimum sample size of 1 kg for testing.”
Laboratories offer a range of tests to assist growers with different decisions. “If you intend planting seed in the next few days then a Tetrazolium Test is a very rapid test (24 hours) that will tell you the percentage of viable seeds,” said Mr Cunliffe. “It won’t tell you anything about abnormal, hard or fresh seeds that may not emerge properly in the field but it can help to avoid planting dead seed.”
If you intend planting seed in the next few weeks then a Germination Test provides the assurance that your seed is in suitable condition for planting. Mr Cunliffe said the Germination Test will show whether the seed has suffered any deterioration and if dormancy (hard seededness) has broken.
When the results come back, look for a ‘Normal’ count of over 85% before deciding to use the stored seed. The results will also show the percentage of ‘Abnormal’ seed, which are unlikely to form healthy productive plants in the field; ‘Hard’ seed, which are still dormant and may go on to produce normal seedlings once dormancy is broken, but if lines have too many hard seeds this will result in uneven establishment; ‘Fresh’ seed, which are unlikely to produce normal healthy seedlings and of course ‘Dead’ seeds are, well, dead!
“Conducting a Vigour Test at the same time will provide an indication of expected field emergence under good conditions,” he said. “The seed count, purity and germination/vigour information from the test enables the grower to accurately work out the required seeding rate to achieve the desired plant population.”
Mungbean seed vigour test. Photo: Ken Cunliffe, AgEtal Agricultural Testing Laboratory.
Another scenario that may require seed testing is if you are planning to store some of the 2018/19 crop for next year’s seed. There is no point retaining seed that is not suitable for planting in the first place.
“The first thing to do is a Moisture Test to ensure that the seed is safe to store. Moisture Test samples must be put into in sealed plastic bags and sent to the lab immediately,” said Mr Cunliffe. “Doing a Germination Test will indicate if the seed meets the basic requirements for seed. If the Germination Test result is marginal, say below 90%, you should consider a Vigour Test to determine if the seed has the potential to perform after a prolonged period of storage.”
Seed laboratories, such as AgEtal, provide a range of different tests and will assist growers to select the tests most appropriate for their requirements.
Seed testing laboratories: