PEANUT DISEASES 299 



gests that sandy soil may be an important factor in making bacterial wilt 

 relatively unimportant in the United States. 



Control. Planting of a resistant variety is the most convenient means 

 of controlling the slime disease of peanuts. From selection work in the 

 East Indies has come the variety "Schwarz 21" which appears to have 

 considerable inherited resistance to the disease. In 1937 this variety was 

 reported as resulting in considerable decrease in loss from bacterial wilt 

 in that area (106). 



A few attempts have been made to control B. solanacearum by soil 

 treatment. Those treatments which might be applied to peanuts offer 

 little hope (42, 110). Application of sulfur to East Indies soil gave no 

 beneficial results on peanuts (42) . 



The control measures recommended in addition to the use of resistant 

 varieties of peanuts are : 



A. Seed treatment; the bacterium can be seed-borne (106). 



B. Planting on hght, well-drained soil (87, 106). 



C. Rotation with crops which seem to be resistant to B. solanacearum 

 such as sweet potatoes, grains and certain legumes (131). 



D. Variation of the rotation to prevent building up other disease-pro- 

 ducing organisms in the soil to the extent that the effects on pea- 

 nuts will be more detrimental than that of B. solanacearum. 



PEANUT RUST 



Importance. Peanut rust, first described from Paraguay (28), ap- 

 parently is distributed throughout South America (10). There are no 

 direct indications of the past or present importance of peanut rust in 

 South America, though Arthur (9) suggested that rust is sometimes a 

 serious peanut disease there. 



There is not complete agreement, but it is generally indicated that 

 peanut rust is serious throughout the West Indies (104). Rust was first 

 reported on peanuts in this area about 1911 (134) and the peanut crop 

 was reported "devastated" by rust in the Dominican Republic in 1925 

 (36). 



Rust of peanuts has been reported sporadically from Florida (28, 

 129). In 1941, KenKnight (74) reported peanut rust from Texas with 

 seven fields of Spanish peanuts in one county infected. 



Description. The existing literature is of little use in evolving a spe- 

 cific description for peanut rust. The symptoms, presumably, are typical 

 for rusts with the pustules of the causal organism as the most useful diag- 

 nostic characteristic. 



