Frances Gould | 10/10/2013 11:30:24 PM
Is there something lurking beneath the canopy of a rice crop that sets off the Cercospora disease? (This article was published in the 2012 Louisiana Rice Research Board Annual Report.) Please click on the links above to go to the Rice Research Board Reports home page, to go to the 2013 report, and to go to the PDF version of the 2012 report.
That’s what LSU AgCenter plant pathologists Dr. Clayton Hollier and Dr. Don Groth want to know. To help answer that question, they installed monitoring devices in five locations in the fields at the AgCenter’s Rice Research Station at Crowley in 2011.
"Cercospora symptoms on rice come at mid- to late season," Hollier said. "One of the things we don’t know is what is the trigger for the disease. It’s probably more of a combination than just one thing."
The monitoring stations Hollier and his colleagues installed record data on wind speed, temperature, rainfall and other climatic factors while the monitoring sensors within the plant canopy measure leaf wetness (dew period) and temperature within the canopy. Rice involved in the study was not treated with fungicides.
"This study will generate a lot of basic information about Cercospora," Groth said.
Hollier said it does little good to look for causes or triggers after the disease has developed. "You start looking beforehand because that influences the infection process," he said.
Monitoring units were placed in plots of five different varieties, as well as plots with varying fertilizer and seeding rates. An attempt will be made to correlate what is happening above canopy with the climatic conditions below the canopy.
"This is the first year, so even the results won’t mean anything yet," Hollier pointed out.
Groth said each variety has a different canopy structure and appearance, and that affects the microclimatic conditions.
Hollier said some varieties produce leaves that lay over on each other, trapping humidity inside the canopy. Hollier recalled that retired plant pathologist Dr. Chuck Rush warned him not to focus solely on rice diseases like sheath blast and blast because Cercospora has the potential for significant crop damage. Farmers found that out in 2006 with an unexpected outbreak of the disease that affected yields.
Checkoff funds for this
project in 2011: $22,000
Go to Report Home Page
PDF Version 2012 Report
(This article was published in the 2012 Louisiana Rice Research Board Annual Report.)
Please click on the links above to go to the Rice Research Board Reports home page, to go to the 2013 report, and to go to the PDF version of the 2012 report.