Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 29, 2006
Publication Date: June 20, 2006
Citation: Grisham, M.P., Johnson, R.M., Richard Jr, E.P. 2006. Effect of soil properties on sugarcane brown rust incidence and severity and associated yield loss [abstract]. Phytopathology. 96(6):S43. Technical Abstract: The extent of spatial and temporal variability of sugarcane rust (Puccinia melanocephala) infestation was related to variation in soil properties in five commercial fields of sugarcane (interspecific hybrids of Saccharum spp., cv ‘LCP 85-384’) in South Louisiana. Sugarcane fields were grid-soil sampled and rust ratings were collected at each point over six to seven weeks. Rust incidence and soil properties were highly variable and were spatially correlated. Rust ratings were correlated with several soil properties, most notably soil phosphorus (r = 0.40 to 0.81) and soil sulfur (r = 0.36 to 0.68). Areas in which nutrients were present at “optimum” or “very-high” levels were frequently associated with higher rust levels. Contour plots of soil properties and rust levels clearly suggested a link between these two parameters. At harvest, spatial variability of yield across two of the rust-affected fields was determined. Rust ratings were negatively correlated with sugar yield and contour plots of these parameters support this association. These combined data suggest that sugarcane growers that apply fertilizer in excess of plant requirements will increase the incidence and severity of rust infestations in their fields and may have yield loss.