SEED YIELD IMPLEMENTATION IN FORAGE SPECIES AND ITS RELEVANCE IN THE MULTIPLICATION PROCESS OF NEW CULTIVARS

M. Romani, L. Pecetti and E. Piano

Istituto Sperimentale per le Colture Foraggere, viale Piacenza 29, 26900 Lodi, Italy

Seed production of forage species in Italy is largely insufficient to cover the national needs.  The intrinsic weakness of the Italian seed trade system accentuated by the limited economic competitiveness of the seed production activity, also in consequence of an inadequate definition of appropriate agronomic practices, hinders seed availability of cultivars released by breeding programmes.  Up to date seed production is often seen as a by-product of the forage cropping.  In most forage species, recently bred cultivars are synthetic varieties.  To avoid genetic shifts during the generations of seed increase in this type of variety, the number of generations of multiplication must be kept to a minimum and this is accomplished both by implementing the production of the breeder seed (Syn 1) to be invested in the next generations of multiplication and by optimizing the field productions of the subsequent generations by an appropriate agronomic technique.  The multiplication scheme envisaged by ISCF Lodi contemplates the establishment of large polycross fields to obtain Syn 1 seed and the production of Syn 2 seed with a specialized crop sown at low seed rate (5-6 kg/ha) in rows 75 cm apart, and properly fertilized and weeded.  Results are presented here on the potential for seed production of specialized crops in the Po Valley for tall fescue, cocksfoot and lucerne.  For all species, the proposed technique led to a good efficiency in the use of seed available for multiplication, with yield comparable to, or greater than those obtained in the same area with higher seed rates in non-specialized crops.  Seed yield, which is traditionally carried out in stands towards the end of their economic life, was here shown to be appreciable even in the ear of sowing.

Keywords: cocksfoot; lucerne; seed yield; tall fescue; variety multiplication.