Interference of sugarcane straw leachates on plant growth

SAMPIETRO, D.A.; SGARIGLIA, M.A.; SOBERÓN, J.R.; VATTUONE, M.A.

Santa Clara (Cuba)

Congreso; 3rd International Conference on Agricultural Development and Sustainability; 2005

Universidad Central de Las Villas (Publicado en Allelopathy Journal 18 (1), vi, 2006)

Previous studies suggested that vanillic, ferulic and syringic acids could participate in the phytotoxic effects of the sugarcane straw leachate on plant growth. The aim of this work was to evaluate the effect of sugarcane (Saccharum spp.) straw leachate and its constituents on the growth of weed and crop plants in unsterile soil, autoclaved soil and autoclaved sand. Amaranthus quitensis L., Bidens subalternans L., Brassica campestris L., Sida rhombifolia L., Lactuca sativa L., Raphanus sativus L., Sorghum bicolor (L) Moench and Triticum aestivum L. were selected as test plants. In unsterile soil, straw leachates stimulted the growth of some test plants at the lowest concentration assayed (6 g l-1) and inhibited the radicle elongation at higher concentrations. The leachates inhibited root elongation in unsterile soil more than in autoclaved soil. In autoclaved sand, the inhibitory effect was stronger than in autoclaved soil. In unsterile soil, vanillic acid stimulated or had no effect on radicle growth of the test plants at the concentration of 19 mg/l while higher concentrations were inhibitory. Low concentrations of ferulic and syringic acids stimulated or had no effect on radicle elongation and high concentrations were inhibitory or had no effect. Phenolic acids inhibited root growth of the test plants in autoclaved soil more than in unsterile soil. Otherwise, the test plants were more inhibitory in sterile sand than in autoclaved soil. Soil microflora and adsorption influenced the biological activity of both the straw leachates and the phenolic compounds. The phytotoxicity of the phenolic acids could not completely explain the inhibitory activity of the sugarcane straw leachate.