Early maize varieties key to maximise winter yields
Growers should be looking to select earlier varieties next season and consider mixing them in the field to maximise cob potential and crop quality.
That is the view of Devon-based Masstock agronomist Mark Smyth, who says 2011 proved to be more problematic and testing than most.
He says many crops in the South West struggled in the dry spring soils - got going in good weather in July - but then were slow to mature after a poor August and September.
“While crops eventually ripened - largely thanks to a warm early October -some were still cutting maize in early November and have struggled to find a dry window to plant following wheats.”
He says normally he would expect to see harvesting finish by October in mid or north Devon, but most crops were later this year and silage has been mixed as a result.
Mr Smyth points out the best crops were those drilled in early April into a well prepared seedbed where there was good soil to seed contact and enough moisture.
He says early varieties are key, especially if farmers want to maximise winter yields and he would advise mixing varieties within the same drill to produce a uniform crop.
“For example I would opt for a Kentaurus/Kreel mix on marginal ground and Salgado/Kreel on better sites.
“Kentaurus does do particularly well in the region, offering very early maturity and high starches, often producing DM yields on a par with later maturing varieties,” he says.
“At the same time, it is less likely to expose the grain when it reaches maturity unlike some other varieties and this reduces the sooty mould and fusarium risk.
“This early maturity, combined with good standing power - a key factor on exposed sites - also allows earlier planting of wheat.
“Kreel is a good stable variety and with its better eyespot resistance is a good partner for Kentaurus on marginal sites.
“Salgado is a bit more of a clamp-filler for use on more favourable sites and has done well over a number of seasons. It also has good eyespot resistance and has always performed well in our trials.
“Mixing Kentaurus or Salgado with Kreel in alternate hoppers in the drill helps to produce a more even crop,” he says. “It’s not an insult to the breeder, simply a way of producing a more uniform crop.”
He says by doing this last year it was possible to secure better pollination in the difficult summer conditions, a lower number of missing grains and also reduced snouting.
“This evens up any cob fill and helps make the best of the season to produce a uniform crop.”
Mr Smyth does though warn growers to take care to minimise eyespot risks. Where maize is to follow maize in the rotation, his advice is to disc stubbles to chop up trash and start the breakdown process before ploughing.
“It is also important to plough down this trash as soon as you can after applying muck or slurry to the ground.
“Eyespot is no issue given a hot summer, with 28degC upwards, but increasingly we are having to use a fungicide containing flusilazole to give three to four weeks extra protection.
“However where you are following maize with wheat the key is to get the more valuable crop in the ground as soon as possible and so an early variety,
despite the higher eyespot risks, maximises establishment and yield potential before soil temperatures decline.
“When it comes to drilling, it is a case of waiting until soils hit 8degC for a week and drill into good freely drained seedbed conditions. This year, crops drilled around April 8 were the earliest to harvest; a bit of frost is not an issue.
“It is also important to take into account amounts of nutrient applied in slurry. Some fields probably get too much muck and we need greater accuracy to assess fertiliser needs - and regular pH testing.
“Phosphate is crucial and use down the spout at drilling alongside nitrogen gives the crop the kick it needs, getting roots down into the soil to pick up reserves from organic manure.”
Advice for growing earlier varieties
- Drill as early as possible into well prepared seedbeds - the best performing crops last year were drilled in early April
- Mix varieties within the drill to get a uniform crop
- Avoid the risk of eyespot in maize followed by maize rotations by going over the stubble with discs before ploughing
- Regularly access soil pH and apply nutrients accurately