It is important to know the disease susceptibility levels of your rice varieties you are considering to grow and how to manage them accordingly. I am getting questions on disease resistance levels for varieties that have not been reported in the “Disease Reaction Table of 2013” (Table 1). If a rating is lacking in the table, it does not mean the variety is resistant to the respective disease. Instead, it simply means we have not seen disease in the past few years.
I also received a few questions on the new Louisiana medium-grain rice variety, Caffey. With the latest projection that medium-grain rice prices may increase due to the drought in California, Arkansas producers could grow more medium-grain rice (Delta Farm Press). We have not seen blast or straighthead on Caffey in Arkansas. According on Dr. Don Groth of LSU, Caffey has better resistance to blast than Jupiter. With that said, Caffey still needs a recommended flood depth to be maintained. If you have to choose between the two varieties on sandy soils, Caffey would be a better choice. Caffey is moderately susceptible to “Straighthead” so, you still need to “drain and dry” as DD50 program recommends, particularly if your field has a history of this phenomenon. Remember Clearfield 261, another medium-grain, is very susceptible to both blast and bacterial panicle blight. To read more on medium-grain rice go to Medium-grain rice considerations by Jarrod Hardke.
Table 1. Rice variety disease reaction (2013)
|Cultivar||Sheath Blight||Blast||Straight Head||Bacterial Panicle Blight||Narrow Brown Leaf Spot||Stem Rot||Kernel Smut||False Smut||Lodging||Black Sheath Rot||Sheath Spot|
|RT CL XL729||MS||R||MS||MR||MS||S||MS||S||S||S|
|RT CL XL745||S||R||R||MR||MS||S||MS||S||S||S||S|
|RT CL XP756||MS||S||S|
|RT XP 753||MS||MR||MS||S||S|
|RT XP 754||MS||S||S||S|
Reaction: R = Resistant; MR = Moderately Resistant; MS = Moderately Susceptible; S = Susceptible; VS = Very Susceptible. Reactions were determined based on historical and recent observations from test plots and in grower fields across Arkansas. In general, these reactions would be expected under conditions that favor severe disease development including excessive nitrogen rates (most diseases) or low flood depth (blast).
Table prepared by Y. Wamishe, Assistant Professor/Extension Plant Pathologist and R.D. Cartwright, Associate Director – Ag and Natural Resources