<P> The most prominent varieties of rice planted within Arkansas, with their respective percentages of acreage occupied of total area under rice cultivation are: Wells (45.2%), Cocodrie (21.8%), Bengal (11.2%), Francis (6.3%), CL 161 (4.7%), and LaGrue (2.6%). Wells, the most prominent variety of rice grown in Arkansas, is a long grain rice actually developed by the University of Arkansas Agricultural Experiment Station in February 1999 in order to increase yields of the crop . Though the long grained Wells variety essentially dominates the rice fields of Arkansas, "Bengal is a successful southern medium - grain released in 1993 and is still the leading medium - grain variety grown in Arkansas ." </P> <P> A number of diseases and pests pose threats to rice cultivation within the state of Arkansas . One such culprit, Pyricularia grisea, commonly known as rice blast, is an invasive fungus that spreads primarily through infected rice stubble from the prior year, related host species and even sometimes infected seed . Though epidemics of the fungus seem to be sporadic (infected seed most likely accounts for the randomness in distribution of the rice blast in Arkansas rice fields), "rice blast has caused significant yield losses in Arkansas ." Another disease that is actually "second only to, and often rivals, rice blast in importance" is sheath blight, which is a soil borne pathogen the initial symptoms of which commonly begin with "lesions on the sheaths of lower leaves when plants are in the late tillering or early internode elongation stage of growth ." The weed that poses perhaps the largest threat to Arkansas rice is barnyard grass, due to its "widespread resistance to propanil and quinclorac, two of the most frequently used herbicides ." Along with this, "weedy red rice (Oryza sativa) is a problematic weed in cultivated rice," and of the rice fields in Arkansas that account for 50% of the nation's rice crop, "about 60% of these...have some red rice infestation ." Weeds such as barnyard grass and weedy red rice can often have detrimental effects to rice fields throughout the state of Arkansas, accounting for over $22 million worth of crop yield losses in 1992 . </P>

What kind of rice is grown in arkansas