Abstract:
Since 1970 the area of silage maize increased from 20 000 ha to 158 000 ha in 1992. In analogy the number of varieties on the national catalogue increased from one (1970) to 112 (1992).
The last 20 years the total dry matter yield and the total digestible organic dry matter yield of silage maize varieties increased on average by 1 % each year.
The increase is mainly due to a higher stem and leaf content.
More early varieties were admitted in the last years.
Such types reach the for harvesting optimal maturity stage sooner and in this way are less affected by bad climatological conditions in late autumn.
An early harvest can also be followed by sowing grass as a manure crop so that the soil is well covered during the winter.
The criteria for the evaluation in the official trials have contributed to the admission of varieties with better qualitative and quantitative characteristics.
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