Red rice in the southern United States was studied using genetic markers to determine its classification. The research found that red rice is a mix of different types, some similar to indica rice and others to japonica rice. Some red rice samples were closely related to a weed called Oryza rufipogon. In Texas, imidazolinone tolerant rice was tested for controlling red rice and other weeds. The study showed that specific application rates and timings of imazethapyr effectively controlled red rice and other weeds in different locations. Overall, the research revealed that red rice in the southern US is a diverse mix of different types and can be effectively controlled with certain herbicides.