Maize for growing under plastic

In very marginal areas, such as Scotland and areas of high altitude in the south west England and North Wales, growing maize under plastic can bring harvest forward by approximately one month compared to open sown crops.

This allows harvesting to take place before weather conditions deteriorate, however this does add considerable extra cost to growing the crop. The plastic system is popular amongst growers of maize for crimped grain, as the use of plastic accelerates maturity, enabling the crop to dry down faster to a 30% moisture content and increasing grain yield thereby, helping to justify the extra cost.

Establishing maize under plastic costs around an extra £300/hectare compared to sowing conventionally. This makes the selection of early maturing varieties a far more cost-effective option for the majority of growers in marginal areas.

Variety selection for use under plastic
Current maize varieties sown under plastic are those that have been bred for the Continental market, which are later maturing. These late maturing varieties tend to achieve higher dry matter yields and so they better offset the extra costs of establishing a crop under plastic than early maturing types.

LG plastic trials are carried out in the south west of England and at the SAC. Results show that all varieties can grow through plastic, however performance does vary. Beacon and Hawk have proven themselves to be suitable for growing in very marginal conditions, as they penetrate plastic cover early, grow vigorously and produce an early maturing crop that yields well.

Currently, the only independent sources of data on how maize varieties have performed under plastic are published by DAFF in Ireland where climatic conditions are similar to many marginal maize areas of the UK. The later maturing LG variety Award is newly recommended for use in plastic covered systems providing an improved quality alternative to Justina, for both crimping and silage.