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ARS Home » Southeast Area » Houma, Louisiana » Sugarcane Research » Research » Publications at this Location » Publication #361166
Research Project: Sugarcane Improvement through Effective Disease Management and Resistance Development

Location: Sugarcane Research

Title: Sugarcane mosaic distribution, incidence, increase, and spatial pattern in Louisiana

Author
item RICE, JANCEE - LSU Agcenter
item HOY, JEFFREY - LSU Agcenter
item Grisham, Michael

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2019
Publication Date: 8/1/2019
Citation: Rice, J.L., Hoy, J.W., Grisham, M.P. 2019. Sugarcane mosaic distribution, incidence, increase, and spatial pattern in Louisiana. Plant Disease. 103:2051-2056. https://doi.org/10.1094/PDIS-01-0099-RE.
DOI: https://doi.org/10.1094/PDIS-01-19-0099-RE

Interpretive Summary: Sugarcane mosaic is a historically important disease in Louisiana currently caused by the Sorghum mosaic virus (SrMV). Successful breeding for resistance reduced the disease to low incidence in commercial cultivars. Recently mosaic was detected in a newly released cultivar, HoCP 09-804, and experimental clones in three of five production areas with incidences ranging from 0 to 10%. Fields of HoCP 09-804 where the incidence was low were monitored for the spread of mosaic in two subsequent annual ratoon crops. Disease incidence increased in some fields and decreased in others in the first-ratoon crop, and decreased in all fields in second ratoon. The results indicated rates of disease were low due to low aphid transmission of the virus under the prevailing conditions. The research showed that control of mosaic in HoCP 09 09-804, a cultivar with positive economic potential, is possible by planting stalks free, or nearly free, of virus infection.

Technical Abstract: Sugarcane mosaic is a historically important disease in Louisiana currently caused by Sorghum mosaic virus (SrMV). Successful breeding for resistance reduced the disease to low incidence in commercial cultivars. However, mosaic was detected in experimental clone evaluations at multiple locations leading to uncertainty concerning the current distribution and incidence in the state. Field surveys were conducted from 2016 to 2018 in breeding program yield trials and experimental clone seed-cane increase fields. Mosaic was detected in a newly released cultivar, HoCP 09-804, and experimental clones in three of five production areas with incidences ranging from 0 to 10%. Single leaf samples were tested for SrMV using reverse transcription polymerase chain reaction. All symptomatic samples and a low percentage (0.3%) of asymptomatic samples tested positive for SrMV, confirming it continues to be the casual species. Runs analysis detected aggregation of infected plants within at least 70% of rows in 94% of surveyed fields. The spatial pattern and geographical distribution of disease incidence suggested infected seed-cane was the source of the disease. Subsequent surveys conducted in the same fields through second ratoon detected disease incidence increases and decreases in first ratoon, but incidence decreased in all fields in second ratoon. The results indicated high rates of disease increase due to aphid transmission did not occur under the prevailing conditions.