By Jessica Buss
THERE ARE many good reasons for selecting an earlier maturing maize variety this year, but later maturing varieties can also offer benefits when grown on suitable sites.
The trend to earlier maturing varieties is becoming clear, with 75% of sales by south west co-op Mole Valley Farmers now in NIAB maturity classes eight or nine, says its arable sales manager Graham Ragg. “Selecting an early maturing variety has become of greater importance, with the aim of harvesting crops earlier.
“In some cases, this is to allow drilling of a winter cereal crop or grass, but increasingly it is for environmental reasons.”
Where crops were not ready for harvest by the end of September, a change of the maturity class of maize grown should be considered, advises Maize Growers Association agronomist Simon Draper. “But in a low-risk situation for soil erosion, harvesting in September may not matter.”
Soil erosion risks vary according to soil type, drilling date, harvest date, height above sea level, rainfall and location within the UK. To assess the maturity class best suited to the farm according to these factors, he suggests using the points scoring system in the MGA Recommended First Choice Variety booklet.
“Also consider whether individual fields have an additional erosion or harvest problem and select a suitable variety based on these risks.”
There are other factors to consider in maize variety maturity class selection too, adds Mr Draper. “When the aim is to produce starch and harvest in September select an early variety. But for a high crop yield in a good situation you can grow a later maturing variety.”
However, he also points out that the lower yields associated with early maturing varieties have been addressed by breeders, so there are some early maturing varieties which now offer high total crop yields.
An early maturing variety can mean a two week difference in crop maturity on a less favourable site, according to MVF member Tim Webb, who farms on the northern edge of Dartmooor.
He grew Fabius and Kingdom last year and reckons his crop was two weeks ahead of others in the area by late June. It was harvested on Sept 26 with a 34.3% starch content. Although dry matter was reduced by rain, it averaged 26.5%, he adds.