Experiments with five caespitose grass species from temperate and tropical environments showed that the number of lateral shoots (tillers) which emerged following defoliation was not increased by leaving a greater residual leaf area. Increased availability of photosynthate was effective, however, in increasing the rate of growth and degree of flowering of new lateral shoots in one tropical species, Panicum maximum. In two temperate Agropyron tussock grasses, decapitation did not stimulate lateral shoot growth. This indicated that apical dominance was not a factor preventing growth of lateral buds just prior to inflorescence emergence on the parent tillers. However, defoliation, where both terminal buds and foliage was removed from the parent tillers stimulated lateral bud growth. In contrast to the temperate species, lateral bud growth was stimulated by both decapitation and defoliation in the three tropical species. These results strongly suggest that lack of carbon resources in defoliated tillers does not limit the stimulation of daughter tillers in these three specie at the morphological stage when the treatments were applied.
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