Quality of maize in the context of variety admission

General introduction

How can we accurately determine the quality of silage maize under the climate and operating conditions in Flanders, taking into account maturation and conservation? The goal of this PhD research is to optimise the criterium of "quality of feed" based on a scientific point of view. The quality of feed is one of the most important criteria used for the official variety tests (an objective evaluation of new varieties before official admission to the variety list and European market). Companies locate their varieties as silage maize, grain maize or dual purpose; as early maturing or late maturing; as stay-green or dry-down; high starch content or high cell-wall content. Apart from genetic influences, the conditions during the season, the harvest and conservation also influence the quality of the end product. During this production process, the harvest date is one of the most important decisions to make.

Research approach

A selection of varieties are planted during two sequential years and on several locations. Harvest occurs three times: the first harvest time corresponds with an early harvest for silage maize; the second harvest time corresponds with a late harvest for silage maize; and the third harvest time corresponds with an early harvest for corn maize. Each variety is analysed for its total yield and the proportion of stem, leaves, cob core, grains and husks. The dry samples as well as ensiled material are chemically analysed and the in vitro digestibility of the total organic matter, the in vitro  cell wall digestibility, and the starch stability are determined.

Relevance/Valorisation

The feeding value of silage maize is an important criteria for admission onto variety lists. Currently, the measuring method of the quality parameter of silage maize is matter for discussion. Not only the analysis technique, but also the harvest time has an influence on the results. A review of the quality parameter for silage maize is necessary. The research results can contribute to scientific-based review of the criteria for admission of silage maize varieties.