Irish maize experiments expand area for growing

Feb 20 2008 The Journal

NEW maize growing techniques being pioneered in Northern Ireland could have major benefits for farmers in marginal areas in the North East.

Experts say a combination of earlier maturing varieties and increased use of plastic is helping expand the Northern Irish maize area.

And Trevor Gilliland, head of the Agri-Food and Biosciences Institute (AFBI) Plant Testing Station at Crossnacreevy, says there’s no reason why the experiences found in the Province shouldn’t be repeated in Northern England.

More crops in the Province are now under plastic than are grown in the open and, as a result, maize is creeping west and north into the more marginal areas.

AFBI has been trialling crops under plastic since 2001 and found clear cost-effectivenesss in terms of yields and maize quality.

He said: “Plastic lifts the early soil temperatures after planting in late April.

“Plants are under the plastic for about a month before they break through and on average this advances silking by three weeks.

“This gives you control over an earlier harvest with better DM and starch yields.”

Last year’s relatively poor season helps illustrate the point.

While early spring conditions were favourable and crops were generally drilled in good time into good seedbeds, summer conditions were very poor with low sunlight hours, restricting growth and yield.

Dr Gilliland said: “Looking at control varieties under open cultivation, we couldn’t get DM above 20% and yields were disappointing at 9t/ha from an October 30 harvest.

“Normally we’d expect 12t/ha at 30% DM.

“This compares to yields under plastic in 2007 which were four tonnes higher at 13t/ha, with a DM of 32%. from a harvest that was three weeks earlier.”

“As an average over the last seven years we have found that using a plastic mulch has consistently hit the 30% dry matter target for the crop, whereas open grown maize has failed to do so in poorer seasons.

“The average plastic yield over these seven years is 16t/ha which is over 3t/ha more than the open maize and most of this extra yield is high value starch.”

Dr Gilliland believes that in practice, growers could gain more from plastic than is found in trial.

“In our work we are comparing like for like varieties, sown on the same day. “However, the use of a plastic mulch gives frost protection and an earlier silking date.

“Therefore, growers can opt for an earlier sowing of a later higher yielding variety under plastic.”

The benchmark variety under plastic in Northern Ireland has been Justina, but for those who can get in very early on the best sites, it is possible to use high-yielding Benicia, although there are risks.