Anisomycin, Mycostatin, and Rimocydin 



These three antibiotics, like Oligomycin and Filipin, are produced by 

 Streptonayces , the genus of molds that provides streptomycin. Anisomycin, 

 Mycostatin, and Rimocydin are products of American pharmaceutical 

 companies and show promise as anti -fungal agents. 



Results of ARS Bean Tests 



Anisomycin, at 50 p.p.m., protected beans from rust and lima beans 

 frona downy mildew infection. At 100 p.p.m., this antibiotic eradicated rust 

 from plants that had been infected as long as 72 hours before the antibiotic 

 treatment. Of the 6 new drugs in this test only Anisomycin demonstrated 

 eradicative powers at the dosages used. 



Mycostatin sprays protected beans from anthracnose, gave partial 

 protection to beans against infection by rust, and partial protection to lima 

 beans against downy mildew. 



Rimocydin gave partial protection to lima beans against anthracnose. 



F-17 



F-17 is a product of the research prograna of the ARS Northern Utili- 

 zation Research Branch, Peoria, 111. Although all of the plant disease- 

 control antibiotics used today are by-products of research in the field of 

 human medicine, ARS scientists believed that antibiotics of great importance 

 could be developed specifically for plant-disease control. Accordingly, 

 some 500 strains of the Streptomyces group of antibiotic -producing micro- 

 organisms were selected for primary screening in 1953. Tests with over a 

 dozen different disease-causing bacteria or fungi cut the field to 200. 

 Further screening reduced the nvimber to 52 microorganisms. Ten of these 

 were selected for the production of antibiotics for innmediate greenhouse 

 testing. 



F-17 is the final result of this basic research. It is the product of the 

 S. cinnamoneous strain, and is made up of three-- and possibly four-- 

 separate antibiotics. This crude mixture has proved effective against 

 fungi on artifical media and on plants in the greenhouse for the control of 

 rust in both beans and wheat. 



ECONOMIC ASPECTS 



The current cost of antibiotics restricts their use to those crops with 

 a high value per acre or where control requires only small quantities of 

 spray materials. Lower cost may come about in either of two ways: First, 

 as the use of antibiotics for plant disease control widens and volume in- 

 creases, mass production of agricultural antibiotics may bring about re- 

 duced prices. Secondly, new and less highly purified antibiotics, selected 

 specifically for plant disease control, naay prove effective at low concen- 

 trations . 



Considerable attention is being directed toward the use of antibiotics 

 as seed treatments. In such case only small quantities would be necessary 

 and application costs would be nominal. The ideal seed treatment would be 

 inexpensive to apply, would not be inactivated or destroyed in the soil. 



