Autecology of Purple Nutsedge (Cyperus rotundus L.) in Sub-Humid Godavari Delta

Twelve locations of nutsedge (Cyperus rotundus L.) infesting non-cropped lands were studied during rainy seasons of 1993 and 1994 to investigate the autecology of the perennial weed in Godavari delta. The study indicated that tuber formation was high in heavy textured soil. Irrespective of soil texture, most of the tubers were found in 10–15 cm depth followed by 5–10 cm depth. Tuber formation was absent beyond 20 cm depth in saturated soils. However, tuber growth was noticed even at 50 cm depth in well aerated soils. With regarding to tuber viability in relation to sunshine exposure, it was observed that the decline in tuber germination was 10-fold when the tubers were exposed 72 h to bright sunshine.