THE EFFECT OF SUBMERGENCE ON TUBER PRODUCTION AND DORMANCY IN 2 SUBSPECIES OF BOLBOSCHOENUS-MARITIMUS

Two subspecies of Bolboschoenus maritimus (L.) PALLA were cultivated i n submerged and non-submerged conditions. The production of tubers, th e proportion of tubers remaining dormant and the time between producti on and reactivation were investigated. Total tuber production was foun d to be dependent on subspecies and may be considered a biological cha racter of the subspecies. Bolboschoenus maritimus ssp. compactus, a su bspecies of less flooded habitats, produced more tubers with a greater capacity for growth leaving a smaller proportion of dormant tubers. I nactivity of tubers and their reactivation after one or two years were enhanced by submergence in both subspecies. The proportion of tubers that are permanently dormant as well as the dormancy of the whole plan t are important features influencing the survival of populations of B. maritimus over periods of unfavourable conditions.