By Yeshi Wamishe, Extension Rice Pathologist
Some rice diseases are more prevalent than others causing significant yield or quality losses. Often the major culprit for yield and/or quality losses in a certain field may just be one or a couple of diseases. Knowledge on susceptibility levels of your cultivars to diseases and your field history are primary phases in managing rice diseases.
Integrated disease management approach is often dependable, lasting and inexpensive. Planting cultivars having some level of resistance to major rice diseases may or may not require fungicide application. Besides fungicides are most beneficial in well managed fields. It is key to match your field history with the variety of your choice. For instance, planting a blast-susceptible variety in historically blast-prone fields is a call for disaster. Likewise, planting kernel and false smut-susceptible cultivars in a field with history and applying excessive nitrogen fertilizer rate is a call for tragedy.
Every season is different. Weather conditions play a role in favoring different crop pathogens. Sometimes weather favors our crops and some other times the pathogens. But mostly favorable weather for our crops is also encouraging for disease development. Therefore, be alert and plan ahead to minimize crop loss due to diseases.
The rice cultivar reactions table below presents reactions determined based on historical and recent observations from test plots and in grower fields across Arkansas and other rice states in southern USA. In general, these ratings represent expected cultivar reactions to disease under conditions that most favor severe disease development.
Reactions are described as: R = Resistant; MR = Moderately Resistant; MS = Moderately Susceptible; S = Susceptible; VS = Very Susceptible. Cells with no values indicate unavailability of definitive Arkansas disease rating information at this time. Disease ratings from the past may have been modified based on series of observations. Lodging may be caused by diseases such as sheath blight; therefore lodging data are included in the table for your additional information.