Caution urged for weather damaged grain
Grain growers experiencing adverse weather this harvest are urged to ensure that, where possible, the grain they retain for 2013 crop seed has a sufficiently high ‘falling number’ value.
Falling number tests at grain delivery measure levels of alpha-amylase – an enzyme resulting from sprouting and which degrades grain starch.
Grains Research and Development Corporation (GRDC) western grower services manager Darren Hughes encouraged growers to pay particular attention to which grain they kept for crop seed, saying weather damaged grain was more susceptible to poor germination, low vigour and degradation during storage and handling.
“Some Western Australian growers forced to retain weather damaged seed from the previous harvest reported that these crops had poor vigour during the difficult start to the growing season in 2012,” he said.
Meanwhile, sprouting research is confirming the huge effect of soil moisture levels during spring on sprouting susceptibility in grain during wet harvests.
Dr Hughes said the findings were part of GRDC-supported work by the Department of Agriculture and Food (DAFWA) aimed at improving understanding of genetic variability between varieties and tolerance to pre-harvest sprouting.
DAFWA senior research officer Kevin Young said this year’s seasonal conditions in WA had confirmed DAFWA researcher Ben Biddulph’s previous research results which showed the significant impact of soil moisture conditions in spring on susceptibility to sprouting.
“Drought stress during the grain fill stage, such as that experienced across much of the grainbelt in 2012, increases seed ‘dormancy’ – one of the main factors inhibiting germination,” Mr Young said.
“This is why some varieties, even after harvest rain, have produced far higher (better) falling numbers than expected this season, especially compared with last year when there was better spring rainfall.
“Another important factor this year is how quickly the crop has so far dried after each rainfall event during harvest.
“Last year we had much longer and cooler periods after each rain.”
Mr Young said varieties varied greatly in their ability to withstand harvest rain.
He said that if growers were forced to retain crop seed with a falling number value below 150, they should arrange a laboratory seed test to establish the germination percentage of on-farm retained seed before sowing, with a vigour test also recommended.
“Handling of the seed should also be minimised to reduce further degradation, and weather damaged seed should be seeded at a higher seeding rate and not too deeply,” Mr Young said.
More information to assist growers in determining whether grain is viable for seeding and wheat is an appropriate seed management program is contained in the GRDC Retaining Seed Fact Sheet at www.grdc.com.au/GRDC_FS_Retainingseed
PHOTO CAPTION: Sprouting research is confirming the huge effect of soil moisture levels during spring on sprouting susceptibility in grain during wet harvests.
Kevin Young, DAFWA
(08) 9083 1130
0428 714 886
Darren Hughes, GRDC
0409 249 420
Natalie Lee, Cox Inall Communications
(08) 9864 2034, 0427 189 827
GRDC Project Code DAW00218