Effects of a sugar-factory byproduct compost on root growth and mycorrhizal infection of sugarcane in Barbados

A compost consisting 95% of the sugar mill byproducts: bagasse, filter press mud, and fly ash, applied at 5 t ha$ sp{-1}$, increased vesicular-arbuscular mycorrhizal infection of sugarcane roots in one of three experimental fields in Barbados. In a plant cane field, compost stimulated formation of intracellular hyphal coils and arbuscules, but not vesicles or hyphae. Infection was greater in roots 35 cm and 65 cm than 5 cm distant from the plant stem, and compost effects were not significant at 5 cm. Two other sources of phosphorus, filter press mud and triple superphosphate, did not affect and suppressed mycorrhizal infection, respectively. Two ratoon crops showed no residual effect of compost on mycorrhizal infection. Compost also stimulated tillering, phosphorus content, and perhaps yield of cane, but did not differentially effect high versus low tillering or sloped versus flat areas. Root length, weight, and specific root length were unaffected by compost addition, but root branching was decreased