Biological Behavior of Cyperus rotundus in Relation to Agro-Ecological Conditions and Imposed Human Factors

摘要

Field and laboratory experiments were conducted to study the biological behavior of C. rotundus over a two-year period (2006-2007). Spatial distribution, viability and tuber formation were investigated. The effect of propagule size, storage conditions, soil moisture and multiple tubers in rhizome chains on tuber sprouting of C. rotundus were determined. C. rotundus forms a large number of tubers per plant, 46% of which are able to sprout. However, 54% undergo dormancy. Distribution of tubers in the soil profile is most abundant in the 0-12 cm layer, accounting for 78.6% of all tubers but the depth can attain 40 cm and is expected to be deeper. In C. rotundus, the apical bud inhibits sprouting in other buds on the same tuber, and the top tuber exertsa similar dominance over the lower tubers in the system. The viability of tubers decreases in an inverse linear manner over an increasing range of burial depth. C. rotundus tubers are very sensible to desiccation. Moisture levels in the soil must increase to a critical level before sprouting occurs, but excess soil moisture deters sprouting. Tuber emergence and emergence time depend upon tuber size and burial depth. Systems to manipulate sprouting may provide new strategies for C. rotundus management.