1. To quantify the effects of genetic variation in compatibility on grass, clover and total mixture yield.
2. To identify morphological and physiological characters which control compatibility in ryegrass white clover mixtures
The physiological basis of compatibility between naturally coadapted white clover and ryegrass (Lolium perenne) populations was examined. The study showed that grasses and clover should be studied in mixtures since aggressive grass varieties can severely suppress clover. It was found that for compatibility, both spatial and temporal effects are important: subtle changes in seasonal growth and development may play an important role in controlling compatibility.
Detailed studies have emphasized the importance of temporal compatibility in the relationships between quantity, characteristics of stolon surviving the winter and subsequent annual clover yield.
Ultimately this information will be of considerable use in the development of effective selection criteria for breeding compatible clover and grass varieties.
A novel feature of these studies was the use not only of bred varieties, but also various grass and clover populations which had co-existed for many years in natural pastures.