Flood Duration and Time of Flood Onset Effects on Recently Planted Sugarcane.

Periodically flooding sugarcane (Saccbarum spp.) by delaying drainage after rain in the Everglades Agricultural Area (EAA) of Florida improves soil conservation and reduces P discharge to the Everglades, but farmers are concerned that flooding recently planted or recently ratooned sugarcane reduces yields. The purpose of this study was to determine the effects of time of flood onset and flood duration on stalk, leaf, and root biomass accretion of two recently planted (plant height ∼9 cm) sugarcane cultivars. In three pot experiments, flood durations ranged from 0 to 6 wk and flood onsets were after 2 or 4 wk at a 30-cm water-table depth. Five treatments also had a second flood onset during the final 4 or 6 wk of each experiment. Increased flood durations often resulted in declines in biomass explained by linear or quadratic models. Compared with 'CP 89-2143,' leaf and stalk biomasses of 'CP 96-1252' were more tolerant of increasing flood durations, but the opposite was true for root biomass. Sugarcane leaf biomass was reduced more by flood onset following 2 rather than 4 wk at a 30-cm water-table depth, but stalk and root biomasses were similarly reduced by both flood onsets. Although previous results have indicated that well-established sugarcane in its grand-growth phase is tolerant to periodic flooding, our results suggest that the biomass of younger (recently planted) sugarcane is increasingly reduced by flood durations of 0 to 6 wk and that flood onsets after 2 or 4 wk at a 30-cm water-table depth are similarly detrimental. [ABSTRACT FROM AUTHOR]