With the recent confirmation of the withdrawal of Mesurol, visitors to this year’s Dairy Show will be able to learn the latest thinking on optimising maize establishment without this seed treatment.
According to the latest rulings, this will be the last year maize growers will be able to specify Mesurol (methiocarb) seed treatments, and so growers need to be looking at options to reduce seed losses and maximise germination at this year’s Dairy Show.
Drilling maize later and deeper could help growers minimise the impact of the disappearance of the popular bird protection treatment, says Grainseed’s technical director Neil Groom.
“Simply switching to growing under plastic is not going to address the issue as birds are very determined to get at seed and many growers have reported bird damage under plastic.
“We think by drilling slightly later and placing seed deeper, however, maize producers can avoid the worst of the problems resulting from scavenging birds and limit the impact of these on yields.
“In other European countries that do not use Mesurol, such an approach has been shown to work well and trials carried out by the MGA and Grainseed in the UK are showing similar results.”
The trials, carried out at Harper Adams University using the group 7 variety Ballade in 2018, showed that increasing drilling depth to 10cm should be considered, he says.
“Ballade was chosen because it’s a good all round maize for silage-making. Untreated seed drilled at 10cm deep in April showed very little plant loss and although this resulted in slightly lower dry matters than when seeds were drilled slightly shallower, the starch contents and overall feeding quality were the same.
“On average, plots drilled on April 15 had 8.5% higher dry matter than the plots drilled four weeks later in May, but those plots drilled at 10cm in May produced 3t/ha more dry matter and only 2% lower starch compared to the April drilled ones.”
The trials have been repeated in 2019 at 2, 7 and 10cm depths in what was generally considered by most growers to be a more ‘normal’ year, Neil Groom adds.
“Obviously we need to wait until harvest to understand the full effects of the different combinations of drilling date and depth but some results are clear already.
“Untreated seed drilled at the 2cm depth resulted in all the plants being taken by birds, so obviously that is too shallow.
“Fairly soon after drilling, the standard depth resulted in a lot of plants being lost on the edge of the trial nearest a large hedge where there is obviously a high proportion of birds, so it is looking like 10cm might be the best option for many growers.
“At the moment we would say if you are likely to have bird problems, the best way to deal with this without Mesurol is to create a good deep seedbed, work on soil fertility and drill at 10cm. In addition, these fields should be left until last so soil temperatures can build up to encourage a faster germination.
A couple of weeks delay could make all the difference, he says.
“A soil temperature of 10-12degC for four consecutive days at breakfast time should be the target.”
Apart from that, the basic management pointers for establishing a strong maize crop should be utilised to ensure the best possible start for plants, he advises.
“Good seedbed preparation will always pay dividends. If you grow maize in the same location each year, weeds will build up so maize should ideally be rotated around the farm.”
“Soil pH of between 6.5 and 7.0 is optimum and removing compaction is essential. A healthy maize plant should have as much depth in roots as growth above the ground so any soil compaction must be addressed.”
Pre-emergence weed control to remove competition is also essential in the first six weeks as is nutrition, he says.
“Placement fertilisers are a good idea with Nitrogen and Phosphate important for the seedling’s early growth. Maxi Maize has protected phosphate so that’s a good choice.”
Finally, drilling crops under plastic is another important consideration, he says.
“Plastic can often benefit growers who might not consider their location needs it. It warms the soil considerably and the warmer the soil the faster seedlings grow.
“For example, trials with the variety Marco grown under plastic have resulted in crop harvest up to one month earlier than usual opening up a range of autumn drilling options.”
**More information on optimising plant establishment without seed treatments can be obtained from the Grainseed and MGA stands at the event.