CARRYOVER EFFECTS ON THE CLONAL GROWTH OF THE GRASS HOLCUS-LANATUS L

The effects of clipping and daylength treatments and their carryover e ffects on the clonal growth of the perennial grass Holcus lanatus L. w ere investigated. Plants from ten clones were grown in six combination s of two daylength and three clipping treatments. Both clipping and lo w daylength reduced the tillering rate of all the clones but the clone s differed in their degree of response to these treatments. After eigh t weeks, the treatments were discontinued and plants were grown in a c ommon environment for seven weeks. Four-week-old tillers from the plan ts were repotted and grown in a common environment to examine the poss ibility of 'carryover' effects of the parental environments. After 8 w k of growth, there were main and interaction carryover effects of dayl ength and clipping on the tillering rates, biomass and tiller extensio n rates of the plants, which, however, differed greatly among clones. These differences among clones in both direct and carryover treatment effects, on clonal growth, indicate how the effects of many different environmental variables may interact to produce an environment that is highly heterogeneous in space and time, influencing the coexistence o f genotypes and species.