Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/17/2014
Publication Date: 11/1/2014
Citation: Grisham, M.P., Johnson, R.M. 2014. Red stripe caused by Acidovirax avenae subsp. avenae in Louisiana sugarcane [abstract]. Phytopathology. 104(Suppl. 3):S3:472.
Technical Abstract: Red stripe of sugarcane caused by Acidovirax avenae subsp. avenae is considered to be of minor importance because, most often when found, only the mild leaf stripe symptom is observed. In 2010, both leaf stripe and the more severe top rot symptom were observed in commercial sugarcane fields in Louisiana. An experiment was established in two naturally infected fields of cultivar HoCP 00-950. One, a plant-cane field, was divided into 113 plots; the other, a first-ratoon field, into 84 plots. A negative correlation was found between disease incidence and kg sucrose yield per hectare with kg sucrose per tonne of cane the component most affecting yield loss. In a nitrogen fertility rate experiment, incidence of red stripe was higher among plots with heavier, clay soils than among those with lighter, more silty soils, and among plots with added nitrogen compared to the plots with no added nitrogen. In another experiment, the effect of planting a new crop with stalks from a field with red stripe was tested. Treatments included planting plots with 1) stalks exhibiting top rot, 2) stalks exhibiting leaf stripe, 3) a mixture of stalks exhibiting both symptom types and nonsymptomatic stalks, and 4) nonsymptomatic stalks only. Stalk stand counts and yield (kg sucrose per hectare) were reduced in the three treatments planted with symptomatic stalks compared to the one planted with nonsymptomatic stalks. Incidence of red stripe was very low in the new crop and first-ratoon crop.