The 2020 forage maize recommended list sees three varieties dropped and one new variety added.

There are now nine varieties suitable for planting under plastic on the Department of Agriculture’s recommended list, each of which have their own strengths. It is important to note that many growers opt to plant maize varieties which don’t feature on the recommended list but which have been trialled in commercial sites in Ireland.

In general, variety selection should be based on location. A maize grower in a less favourable site would be recommended to select an early maturing variety particularly if sowing late in the season. A maize grower in a favourable site would generally be recommended to select a late-maturing variety, particularly if sowing early in the season.

Certain sites in favourable locations may be suited to growing maize in the open without plastic. The Department of Agriculture stopped its trial work on varieties suitable for planting in the open in 2015 and this remains the only source of independent trial information available.

Varieties recommended for 2020

This years recommended list is shown in Table 1. The data shows a range of performance and quality characteristics on which the varieties are evaluated. As always, the recommended list is formulated over a number of sites and the evaluation is expressed as the average of these sites in the three most recent years. The trials were located in Cork, Kildare, Louth, Meath and Kilkenny during the period 2017 to 2019

Ambition (R): This is the lowest-yielding variety on the list but has the highest starch content. It has extremely high dry matter (DM) content and is an extremely early maturing variety. It is suitable for late sowing and/or early harvest, particularly on marginal sites. It is bred by Limagrain Verneuil Holding, France, and the agent is Goldcrop Ltd.

Konfluens (R): This variety was first provisionally recommended in 2019 and has now been upgraded to fully recommended in 2020. This is a very high-yielding variety with moderate starch content. DM content is good and it is a medium-maturing variety. The agent is DLF Seeds and it is bred by KWS Saat, Germany.

LG30211 (R): This variety has a moderate yield with good starch content. DM content is good and is a medium-maturing variety. Bred by Limagrain Verneuil Holding, France. The Irish agent for the variety is DLF Seeds.

LG31.235 (R): This variety first entered the recommended list with a provisional recommendation in 2019 and has been upgraded to fully recommended in 2020. It is a high-yielding variety with good starch content. DM atter content is good and it is a medium-maturing variety. It is bred by Limagrain Verneuil Holding, France, and the agent is Goldcrop Ltd.

P7932: (PR-1): New to the list this year with a provisional recommendation is P7932. It is the highest-yielding variety on the recommended list. It has the lowest starch content on the list. It has low DM content and is a late-maturing variety. It generally should only be sown early on favourable sites. The variety is bred by Pioneer.

P8200 (R): It is a very high-yielding variety with a moderate starch content. It has good DM content and is medium-maturing. It is bred by Pioneer.

P8201 (R): This is a very high-yielding variety with a high starch content. DM content is good and it is medium-maturing. It is bred by Pioneer.

Spyci CS (R): This is a moderate-yielding variety with high starch content. DM content is high and it is an early-medium-maturing variety. It is bred by Caussade Semences and the agent is Goldcrop Ltd.

SY Feeditop (R): This is a moderate-yielding variety and has high starch content. It has a high DM content and is an early-medium-maturing variety. The variety is bred by Syngenta and the agent is Goldcrop Ltd.

Changes to agronomy

The withdrawal of the seed dressing Mesurol could pose a problem for bird control this season. Registration for the product expired on December 31 2019 and the product will no longer be permitted for use from 3 April 2020. The methiocarb-based seed dressing greatly reduced the likelihood of bird damage.

However, John Foley, managing director of Maizetech, said the withdrawal of Mesurol had been expected and other treatments have been found to be effective. Changes to the type of plastic which growers are permitted to use will come into effect in 2022, he added. The post-emergent herbicide Calaris is still available in the Republic of Ireland for use on maize but is no longer available in Northern Ireland.

Feeding maize silage

Maize silage is a high-energy but low-protein crop. One of the main issues with maize is the variability in terms of yield and quality.

The key quality parameter is starch as this indicates the energy levels in the crop. Starch values range from 25% to 35%, but vary widely depending on the weather during the growing season. Protein levels are more stable but low at 9% to 10% so like with fodder beet, supplementation with protein is necessary. Mineral and vitamin supplementation will be required also.

– Aidan Brennan