How and where are the varieties tested?
All phases of the variety research - both for admission to the national variety list and for the descriptive and recommended variety list per crop - are carried out in accordance with GEP (Good Experimental Practice) and GLP (Good Laboratory Practice).
Preparation of the seeds and choice of test fields
The growers send non-disinfected test seed to the research centers (ILVO and CRA-W). According to common practice, all the test seed per variety is disinfected in the same way for each crop with specific test field equipment. After disinfection, the 1000-grain weight and germination capacity of each variety is determined according to the ISTA (International Seed Testing Association) guidelines. Every year, all varieties are sown at all locations at the same sowing density. This is based on the number of desired germinating seeds per m², and is calculated on the basis of the germination percentage and the 1000-grain weight. With maize, the results of a cold test are also taken into account. This is a test in which the seeds are germinated in the lab at low temperatures (7 °C). This test provides a better prediction of field attendance compared to the ISTA test. Beets and maize are densely sown, then thinned at an early stage to obtain the same planting density for each variety.
The trials are set up on practical farms and research centers. When choosing the trial field, the homogeneity of the field and the pre-cultivation is important. The trial fields are fertilized based on a soil analysis, the needs of the crop and the applicable fertilization standards. Disease control is not applied; pests and weeds are controlled.
Dissemination of the variety trials in Belgium
The tables below provide an overview of the distribution of the variety trials per soil type and the number of trial fields throughout Belgium.
| Agricultural area | Silage maize | Corn maize | Fodder beets | Grasses | Red and white clover | Leaf cabbage and marrow stem kale |
|---|---|---|---|---|---|---|
Polders | - | 1 | - | - | - | 1 |
Sandy area | 1 | - | 1 | 1 | 1 | - |
Kempen | 1 | 1 | - | 1 | 1 | 1 |
Sandy loam area | 2 | 2 | 2 | 2 | 2 | 1 |
Loam area | 1 | 2 | 1 | - | - | - |
Condroz | 1 | - | 1 | - | - | - |
Ardennes | - | - | - | - | - | - |
Total | 6 | 6 | 5 | 4 | 4 | 3 |
Table: Distribution of the variety trials with forage crops in Belgium
| Agricultural area | White mustard and Fodder radish | Rye | Facelia | Summer vetches | Winter vetches |
|---|---|---|---|---|---|
Polders | - | - | - | - | - |
Sandy area | 1 | 1 | 1 | 1 | 1 |
Kempen | 1 | 1 | 1 | 1 | - |
Sandy loam area | 2 | 2 | 2 | 2 | 2 |
Loam area | - | - | - | - | - |
Condroz | - | - | - | - | |
Ardennes | - | - | - | ||
Total | 4 | 4 | 4 | 4 | 3 |
Table: Distribution of the variety trials with green cover crops in Belgium
Observations and analyses
During the growing season and at harvest, various characteristics important for the admission criteria, are assessed. These admission criteria are based on the most important agricultural characteristics for the practice. The table below shows these characteristics per crop.
At each test location, the observations are made according to the same prescribed protocol. For example, uniformity is pursued in the assessment of all visual and measurable parameters. Quality analyses are performed on various crops at the ILVO-Plant chemistry lab.
| Crop | Characteristics for admission to the national variety list | Additional characteristics for descriptive and recommending variety list |
|---|---|---|
Silage maize | Earliness (precocity), total | Early growth, plant length, height of |
Corn maize en | Grain yield (15% moisture), | Early growth, plant length, height of |
Grass (general) | Total dry matter yield, persistence | Date of flowering, earliness of heading |
White and red clover | Yield green mass, | Winter hardiness, mildew resistance, |
Fodder beets | Yield of dry matter from the roots, | Ground cover speed, color |
Turnip | Total dry matter yield, susceptibility | Leaf density |
Cabbage | Dry matter yield, digestibility, | Ground cover, lodging resistance |
Fodder radish | Dry matter yield, date of flowering, | Nematode resistance, lodging resistance |
Facelia | Ground cover speed, | - |
Ryegrasses | Same characteristics as grass | - |
Rye | Degree of ground cover before and after the | - |
Summer vetches | Dry matter yield | Speed of ground cover, health |
Winter vetches | Degree of ground cover before and after | - |
Table: Characteristics determining the authorization, description and recommendation of forage crops and green cover crops
Processing of the results and number of years of testing
All data from observations, measurements and analyzes are collected and statistically processed. Only trials with a sufficiently low coefficient of variation are retained. Based on this data, a report is drawn up per crop and presented to the relevant working group and the Interregional Technical Working Group. The table below provides an overview of the number of trial years per crop required for admission to the national variety list.
The best varieties can be included on the Belgian variety list after two years. Most are tested for three years. Varieties that are included after two years remain in the collection for at least one more year.
| Variety | Crop | Number of years of testing before admission |
|---|---|---|
Forage crops | Silage maize | 2 (3) |
Forage crops | Corn maize | 2 (3) |
Forage crops | Perennial grasses | 4 |
Forage crops | Temporary grassland | 2 (3) |
Forage crops | Clovers (white, red) | 3 |
Forage crops | Fodder beets | 2 (3) |
Forage crops | Cabbage | 2 (3) |
Green cover crops | White mustard | 2 (3) |
Green cover crops | Fodder radish | 2 (3) |
Green cover crops | Phacelia | 2 (3) |
Green cover crops | Vetches | 2 (3) |
Green cover crops | Rye | 2 |
Table: number of years of testing before admission to the Belgian Variety List