Maize seed has exacting requirements for sowing depth and fertiliser placement and a Sussex training day illustrated the importance of setting the machine up correctly.
Peter Hollinshead went along to find out more...
Maize drills need to be set up carefully if yield penalties are to be avoided and starter fertilisers not completely wasted.
Worn seed coulters can mean inaccurate sowing depths and worn fertiliser coulters mean seed nutrients become inaccessible.
According to MGA agronomist Simon Draper, inaccurate sowing depths can lead to uneven plant size and ultimately yield loss – and inaccurate phosphate placement could fail to benefit the germinating seedling.
Speaking at a Certificate of Competence in Maize Drilling course at Plumpton College in East Sussex, he said any phosphate should ideally be deposited around 10mm from the seed, whereas the nitrogen can be taken up at anything from 25-50 mm.
However, he warned that placing the fertiliser too close could damage the seedling, so any fertiliser should be placed 1-2 cm diagonally away and to the bottom of the seed.
“Starter fertiliser can be wasted if not placed in the right spot and the coulters need to be set to ensure accuracy,” he declared.
He also said deeper drilling will be needed next year with the removal of the bird repellent mesurol, when the current 4-5cm depth will need to be increased to 8-10cm to stop rooks getting at the seed.
“This could potentially mean later drilling as the soil temperature needs to be 8-10deg C at that depth,” warned Mr Draper.
He accepted this could mean later harvests and said variety selection would become even more relevant next season if growers were to maintain the early harvest dates they strive for.
He also warned maize growers in the southern part of the country of the growing threat from the corn borer which has come across from the continent and survived in our recent mild winters.
“The corn borer is a moth which lays its eggs in the stem of the plant and the resultant larva bores its way out near or even in the cob, creating a huge hole which causes the plant to collapse – you can tell it’s the corn borer by the lodging being in all different directions,” he said.
Corn borer reports come from all across the south of England as far up as Oxfordshire, although the colder climes further north may preclude further geographical progress.
He said the larva can overwinter in the bottom 3ins of the plant stem and this is where the danger lies, especially if the crop is repeatedly grown in the same field.
“We need to smash the stem down its length so the larva is exposed, using something like a power harrow in November or December. Then the cold weather will destroy the larva – if the stem is not opened up the larva will cause problems in future years.
“There is nothing you can do for the coming season, as the winter weather has passed, except to plough the ground which will reduce the chances of larva survival,” he claimed.
**The Certificate in Competence in Maize Drilling was set up by Bright Maize Ltd and so far around 60 certificates have been awarded.