With half of his 2023-hectare cropping program sown to canola, it is imperative that Lower Eyre Peninsula farmer David Giddings applies best-management practices to avoid the fungal disease blackleg.
“In this region the density of canola makes it impossible to sow 500 metres from last year’s canola stubble, as recommended, so I have to apply all other management options vigilantly,” David says.
Lower Eyre Peninsula grower David Giddings applies
a range of management options to keep blackleg
from his canola crop
PHOTO: Emma Leonard
David starts sowing early and aims to have the whole program – the other 50 per cent being wheat – sown within 10 days. He selects varieties with good levels of blackleg resistance and uses the new blackleg resistance groups information to rotate the resistance genes on which he relies.
Seed and fertiliser are treated with two different fungicides, but so far David has not used a foliar fungicide to control blackleg in-crop.
At his property near Wanilla, the average rainfall is 450 to 500 millimetres, but can peak at 600mm. He targets a wheat yield of 3.5 to 4 tonnes per hectare and produces between 1.5 to 2.5t/ha of canola from a seeding rate of 2 to 2.5 kilograms/ha.
“Previously we sowed canola at 5kg/ha but reducing the seeding rate and sowing earlier has seen an improvement in disease, yield and water use efficiency across our sandy loam soils, many of which have a sodic subsoil.”
Understanding the value of sowing early has been the focus of a canola trial he hosted on his property for the local farming systems group Lower Eyre Agricultural Development Association (LEADA). Early, mid and late-maturing canola varieties were sown dry on 20 April 2012, then two weeks later and a further two weeks after that.
Initial results have shown the mid-season variety Hyola® 575CL produced 400kg/ha more when sown dry. Full results will be available on the LEADA Facebook page.
“Dry sowing has not been practised widely in this region and the purpose of the trial was to show that plants will establish and that early sowing can boost yield,” David says.
“Sowing a small part of the cropping program dry will help the productivity of the whole cropping program as all crops will be sown earlier.”
2013 will see some changes in David’s system. All operations are going to be based on 4m wheel tracks, phosphorus at seeding will be varied on a replacement basis, and lupins are returning to the rotation after a three-year absence.
The aim behind these changes is to improve productivity and profitability, while maintaining a simple system.
Related Feature: Pragmatism rules crop management
Next: Supply-chain challenge as global demand climbs (Part 1)