Abstract
A system dynamic model of dry matter distribution between each inflorescence was constructed for sweet pea plants during flowering. The amount of dry matter distributed to each inflorescence is proportional to the product of dry matter and the relative growth rate of the inflorescence in the model. When the total dry matter supplied to the inflorescence per day is changed, the change of dry matter of the inflorescence is continuous without converging. Conversely, when the total dry matter supplied to the inflorescence per day is kept constant, the change in dry matter of the inflorescence converges immediately. From these simulation results, the hypothesis was formulated that the change in dry matter of an inflorescence is suppressed by reducing the change in total dry matter supplied to the inflorescence. Next, bud abscission and fluctuation in the number of buds per inflorescence under overnight supplemental lighting conditions on cloudy or rainy days was investigated. Overnight supplemental lighting of photosynthetic photon flux density 80 μmol·m−2·s−1 enhanced dry mass production. This hypothesis was not supported because supplemental lighting treatment had no effect in suppressing fluctuation in the number of buds per inflorescence; however, supplemental lighting treatment was effective in preventing bud abscission and suppressing fluctuation in the number of buds per cut flower.
