PERSISTENCE OF LADINO WHITE CLOVER ECOTYPES AND ITS RELATIONSHIP WITHOTHER AGRONOMIC TRAITS

Sixteen landraces and twelve natural populations of Ladino white clove r, and six large-leaved control varieties, were assessed in Lodi (sout hern Lombardy, Italy) under a mowing regime for persistence, defined a s ratio between clover dry matter (DM) yield over the last two years a nd clover DM yield over the five-year crop cycle. Clover content in th e sward was on average 35.2% in the fourth year and only 5.5% in the f ifth year. Natural populations showed greater persistence and larger v ariation for this feature than landraces. Six natural populations were more persistent and higher yielding in the long-term than the Italian variety Espanso and one of these populations performed better than th e best of the control varieties, namely Lune de Mai and Olwen, at P<0. 05. Persistence of the ecotypes was positively associated with stolen density and DM yield assessed in the third year, and to internode leng th, whilst it was inversely related to seed yield and its components, especially the production of seed heads, so that hardly any ecotype co uld combine good persistence with high seed yield. This study discusse s the potential use of these genetic resources in white clover breedin g and suggests stolen density as a low-cost, approximate indicator of long-term yield.