Relationship of soil properties and sugarcane yields to red stripe in Louisiana

Authors: Johnson, Richard; Grisham, Michael; Warnke, Kathryn; Maggio, Jeri

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2016
Publication Date: 6/13/2016
Publication URL: http://handle.nal.usda.gov/10113/62690
Citation: Johnson, R.M., Grisham, M.P., Warnke, K.Z., Maggio, J.R. 2016. Relationship of soil properties and sugarcane yields to red stripe in Louisiana. Phytopathology. 106:737-744.

Interpretive Summary: Symptoms of red stripe disease caused by Acidovorax avenae subsp. avenae in Louisiana observed by the authors between 1985 and 2010 were limited to the leaf stripe form which caused no apparent yield loss. During 2010, the more severe top rot form was observed in several commercial sugarcane fields. A field study was initiated to investigate the effects of red stripe on cane and sugar yields, and to determine if incidence levels were related to soil properties. Two fields of cultivar HoCP 00-950, one plant-cane crop and one first-ratoon crop affected by top rot were subdivided into 113 and 84 plots, respectively, soil sampled, and red stripe ratings were determined at each location at two separate times. Soil properties data, red stripe incidence and sugarcane yields were all highly variable and were not randomly distributed in the field. Samples that were closer tended to be more similar than those further apart indicating that their distrubution was spatial. Combined harvest data showed a negative correlation between yield components and red stripe incidence with the strongest relationship between sucrose per tonne and disease incidence. Red stripe incidence was positively correlated with several soil properties, when locations were combined, including phosphorus, potassium, zinc and calcium. The results from another field experiment that included treatments to which different amounts of nitrogen fertilizer were added showed that the incidence of red stripe increased with increasing N rate with the greatest effects in heavy soils. Finally, results of a third test indicated that using red stripe infected cane as a seed source can significantly decrease shoot emergence, stalk population, and subsequent cane and sugar yields. These combined data suggest that red stripe disease can exhibit a highly variable rate of infection in commercial sugarcane fields and may also significantly decrease sugar yields. The rate of infection can be influenced by soil properties and cultural practices, suggesting that management of these factors may help control the extent and spread of the disease.

Technical Abstract: Red stripe of sugarcane caused by Acidovorax avenae subsp. avenae consists of two forms: leaf stripe and top rot. Symptoms of red stripe in Louisiana observed by the authors between 1985 and 2010 were limited to the leaf stripe form which caused no apparent yield loss. During 2010, the more severe top rot form was observed in several commercial sugarcane fields. Both forms were found, either separately or together. Two fields of cultivar HoCP 00-950, one plant-cane (PC) crop and one first-ratoon (FR) crop, affected by top rot were subdivided into 113 and 84 plots, respectively. Each field was grid-soil sampled (at several intensities) and red stripe ratings were collected at each point at two separate times. Soil properties exhibited significant variability (CV=6 - 64%) and were spatially correlated in 12 of 28 cases with a range of spatial correlation varying from 43 to 95-m. Red stripe incidence levels were also highly variable with a CV ranging from 65 to 92% and were spatially correlated in three out of four cases with a spatial range of 19 to 84-m. Sugarcane yields exhibited a CV ranging from 6 to 27% and were spatially correlated in four out of six cases with a range varying from 6 to 490-m. Red stripe incidence was correlated with several soil properties, when locations were combined, including phosphorus, potassium, zinc and calcium. Red stripe incidence was also significantly correlated with sugarcane yields, most notably theoretically recoverable sucrose (TRS) (r = -0.34*** to -0.61***) and sugar yield (r = -0.21** to -0.36***). Finally, contour plots of soil properties and red stripe incidence levels clearly suggested a link between these two parameters. In another field experiment that included treatments to which different amounts of nitrogen fertilizer were added, disease incidence, nitrogen (N) fertility rate, and soil texture interactions were noted. Incidence was higher in the heavy clay soil verses the lighter, more silty soil. Disease incidence increased with increasing rates of added N in the heavy clay soil compared to the no nitrogen-added plots. In the lighter soil, disease incidence was higher among treatments with added N compared to the control, but incidence did not differ among plots with the different rates of added N fertilizer. Finally, in a seed-cane yield loss study, results indicated that using red stripe infected cane as a seed source can significantly decrease shoot emergence, stalk population, and subsequent cane and sugar yields. These combined data suggest that red stripe disease can exhibit a highly variable rate of infection in commercial sugarcane fields. The disease may also significantly decrease sugar yields. The rate of infection can be influenced by soil properties and cultural practices, suggesting that management of these factors may help control the extent and spread of the disease. One potential example would include avoiding excess nitrogen application, particularly on fine-textured soils.