Location: Sugarcane ResearchTitle: Quantification of red stripe variability in Louisiana sugarcane using precision agriculture methods Author
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2015
Publication Date: 6/1/2015
Citation: Johnson, R.M., Grisham, M.P. 2015. Quantification of red stripe variability in Louisiana sugarcane using precision agriculture methods. Journal of the American Society of Sugar Cane Technologists. 35:45.
Technical Abstract: Red stripe of sugarcane caused by Acidovirax avenae subsp. avenae consists of two forms – leaf stripe and top rot. Symptoms of red stripe in Louisiana over the past 25 years have been limited to the leaf stripe form which causes no measurable yield losses. 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 ratings were also highly variability with a CV ranging from 65 to 92% and were spatially correlated in 3 out of 4 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 4 out of 6 cases with a range varying from 6 to 490-m. Red stripe ratings were correlated with several soil properties, when locations were combined, including phosphorus, potassium, zinc and calcium. Red stripe ratings were also significantly correlated with sugarcane yields, most notably TRS (r = -0.34*** to -0.61***) and sugar (r = -0.21** to -0.36***). Contour plots of soil properties and red stripe ratings levels also clearly suggested a link between these two parameters. Red stripe symptoms were also observed in nitrogen fertility trials conducted with HoCP 00-950 in two soil types. The incidence was higher among plots in clay soils verses lighter, more silty soils. Disease incidence also increased with increasing rates of added nitrogen in the heavy clay soil compared to the no nitrogen- added plots. In the lighter soil, disease incidence was higher among treatments with added nitrogen compared to the control, but incidence did not differ among plots with the different rates of added nitrogen fertilizer. Finally, in a planting study, results suggested that using red stripe infected cane as a seed source can result in significantly lower shoot emergence counts, stalk counts and subsequent cane and sugar yields. These combined data suggest that red stripe disease cane exhibit a variable rate of infection in commercial sugarcane fields. The disease can also significantly decrease cane and sugar yields. The rate of infection is influenced by soil properties and cultural practices, suggesting that proper management of these factors may help control the extent and spread of the disease.