1. A proposal for an international nomenclature of races of Phytophthora infestans and of genes controlling immunity in Solanum demissum derivatives

   • W. Black
   • C. Mastenbroek
   • L. C. Peterson

   OriginalPaper Pages: 173 - 179

2. Breeding for resistance to potato root eelworm

   • H. J. Toxopeus
   • C. A Huijsman

   OriginalPaper Pages: 180 - 186

3. The creation of tetraploid beets

   • D. Kloen
   • G. J. Speckmann

   ReviewPaper Pages: 187 - 196

4. Experiments on the inheritance of blight immunity in potatoes derived from solanum demissum Lindl.

   • C. Mastenbroek

   OriginalPaper Pages: 197 - 206

5. Combined plant introduction for Western Europe?

   OriginalPaper Pages: 207 - 210

6. Fifteen years activity of the Commission for the Advancement of Potato Breeding

   ReviewPaper Pages: 211 - 223

7. The significance of andromonoecism for the breeding of Asparagus officinalis L. II

   • J. Sneep

   OriginalPaper Pages: 224 - 228

8. Het gebruik van een handrefractometer bij de drogestofbepaling van voederbieten

   OriginalPaper Pages: 229 - 233

9. Reviews of books

   BookReview Pages: 234 - 236

10. Reviews of Dutch articles

    BookReview Pages: 236 - 236

11. Notes

    Announcement Pages: 237 - 239

12. News items

    Announcement Pages: 239 - 240