Allelopathic activity of sugarcane (Saccharum spp) leaf extracts

SAMPIETRO, D.A.; VATTUONE, M.A.; ISLA, M.I.

Punta del Este (Uruguay)

Congreso; XI Reunión Latinoamericana de Fisiología Vegetal; 2002

Soc. Argentina de Fisiol. Vegetal - Facultad de Agronomía de la Univ. de la Republica (Uruguay)

The phytotoxicity of sugarcane leaf aqueous extracts in an early decomposition was evaluated on germination and seedling growth in laboratory bioassays. Seeds of Daucus carota, Lycopersicon esculentum, Allium cepa, Triticum aestivum, Ipomoea purpurea,  Sorghum X saccharatum, Raphanus sativum and Lactuca sativa were  bioassayed. Distilled water and four concentrations of NaCl were included as control. The extracts considerably reduced seed germination and radicle and shoot lengths. Comparing I25 values (estimated concentration at which 25% inhibition occurs),  sugarcane extracts inhibited seed germination of dicotyledonous more than that of monocotyledonous species. The species less affected on radicle elongation were Ipomoea purpurea and gramineae crops. The sugarcane leaf extracts inhibit the root elongation more than shoot length except in Ipomoea purpurea and Daucus carota. The concentration dependent responses of the test plants to the aqueous extract suggest that sugarcane residues release water-soluble toxins and could be used to supress seed germination and seedling growth of  common weeds reducing the need of chemical controls in commercial crops.