Although once of major importance, the oats smuts are now of minor 
importance owing primarily to the widespread use of resistant 
varieties. They also can be controlled by seed treatment. 
Red leaf, caused by a virus, has caused estimated losses of 3.8 
percent for the 10-year period. It stunts the plants with a result- 
ing loss in yield and quality. It is widely prevalent over the 
United States. 
Root and culm rots cause blight of seedlings and root necrosis of 
adult plants, reducing stand vigor and yield for pasture and grain 
production. They are prevalent over the oat-growing areas but more 
severe in humid areas or wet years. 
Rice 
Rice is grown in the South, especially in Arkansas, Louisiana, and 
Texas. (Some is also produced in California, but the following 
account refers specifically to the southern crop.) 
Seedling blight, leaf spotting, sterility, and discoloration of 
the kernel cause heavy losses of rice. 
Seedling blight is probably responsible for a reduction in yield 
of about 2 percent each year. The losses caused by leaf-spotting 
fungi and by sterility, which is due to early infection of the 
florets and pedicel, are difficult to estimate but are probably 
about 2 percent. 
Losses from blast have not been great during the past 10 years, 
because Zenith, which is resistant to the race of the organism 
prevalent in Arkansas, has been grown in most places where this 
disease usually occurs, Had a susceptible variety such as Early 
Prolific or Caloro been grown, losses might have been 2 percent 
annually in Arkansas alone, and somewhat less in the other southern 
States. In 1951 and 1952 this disease caused serious damage to the 
small acreage in Florida. Zenith is susceptible to a race of the 
blast fungus found in Florida, If this race should spread to 
other southern rice-growing States, the losses could be greater 
than for any other disease. 
In each of the 10 years approximately 0 percent of the southern 
rice acreage has been sown to varieties that are susceptible to 
white tip. In experiments at Stuttgart, Arkansas, effective control 
of white tip gave an average increase of 17 percent in yield. On 
the assumption that 25 percent of the acreage of susceptible varieties 
was reduced in yield as much as were the untreated plots in these 
experiments, the annual reduction in yield would be about 1.5 percent 
of the total crop. 
Sterility of the type generally called straighthead and a similar 
injury caused by a toxic concentration of arsenic in the soil cause 
a loss of about 0.1 percent annually. 
- 20) = 
