Maize recommended varieties | Maize variety search

The use of plastic film has a substantial effect on the temperatures around the base of the plants. Temperature increases of around 30%, measured as accumulated Ontario Heat Units (OHU), have been recorded at Crossnacreevy and this advantage extends more than 10cm below the soil surface. Most of this additional heat occurs in May, June and very early July before the crop canopy fully closes. This causes the crop to germinate quicker, emerge earlier and grow faster up to silking in July. The impact of this on the performance of the crop is considerable.

These results are the average of the last four years, for the best five varieties in each year under the Plastic system. This was repeated exactly for the Open system. In both cases ‘best’ was defined as ‘highest starch yielders’.

The table shows that in addition to advancing silking by 19 days, all other important performance characters are improved. During the five years 2001 to 2005 the average gains were a 25% total DM yield increase, a 60% increase in starch yield and a 30% increase in ME yield. In addition to these increased performances, the use of plastic mulch allows growers to sow their crops several weeks earlier than would be possible for open established crops. As the Open and Plastic variety trials have to be sown on the same day, this additional advantage is not evident in the table above. It has been estimated that this could add at least an additional 1 t/ha of total DM yield, most of which will be starch. Performance gains of these magnitudes are considered to substantially exceed the additional costs of the plastic mulch system.