Rhizome allocation

The Jerusalem artichoke can reproduce by two primary means. It can reproduce and colonize an area by the allocation of photosynthate and nutrients into both asexual (tubers and, to a lesser extent, rhizomes) and sexual (seed) reproductive organs. Flexibility in the amount of resources allocated between sexual and asexual means of reproduction confers a selective advantage in that conditions that inhibit or block sexual production (lack of pollen, herbivory of floral structures, undesirable weather) allow increased allocation to asexual reproduction. Artificially reduced allocation of resources to sexual reproduction, for example, results in a substantial increase in those allocated to asexual means. With flower bud removal, more (82 vs. 69) and larger (4.4 vs. 3.8 g) tubers were formed per plant than those with unlimited sexual reproduction (Wesdey, 1993). Total biomass was not altered, potentially indicating a relatively complete diversion of resources to asexual reproduction when sexual reproduction is blocked. From a reproductive standpoint, the risk of making it to the next season is high with sexual reproduction and relatively low with asexual reproduction. Increased investment in tubers increases the opportunity for sexual reproduction in the future. 

Dong, M. and de Kroon, H., Plasticity in morphology and biomass allocation in Cynodon dactylon, a grass species forming stolons and rhizomes, Oikos, 70, 99-106, 1994. 

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