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Tenn. Associations of Soil Microorganisms as Related to Plant 

 Diseases , To (1) determine associations of saprophytic soil 

 microorganisms with pathogenic soil microorganisms which enhance 

 ability to produce epidemics; (2) use antagonistic soil organisms 

 for reducing diseases; and (3) devise crop successions that will 

 through soil microbiological action reduce ability of semiparasitic 

 organisms to incite disease. 

 PI. Path. 139 (S-26) 



Va. The Fungus Flora of Agricultural Soils in Virginia , (l) Learn 



fungus flora of agricultural soils in State j (2) correlate presence 

 and distribution of specific fungi with soil types, crop plants, 

 and other ecological factors; (3; study role of soil fungi in 

 decomposition of organic materials and in conservation of inorganic 

 N compounds and minerals. 

 Biol. 86090 



Wis. Interrelationships Between Soil Insecticides and Soil Mirco- 



organisms. Ascertain effects of insecticide treatment on soil 

 mciroorganisms and vice versa. 

 Bact. 897a (NC-19) 



Wyo. Development and Evaluation of Methods of Study of Fungus- 

 Induced Root Diseases , (1) Devise and evaluate a rapid, effici ent , 

 reliable method of isolating fungus pathogens of root diseases of 

 as many crops as possible; (2) develop methods of experimentally 

 establishing the degree of virulence and host range of a pathogen 

 yielding reproducible results. 

 Agron. 598 (W-38) 



Disease Resistance 



Calif. The Physical and Chemical Bases of Plant Disease Resistance . 

 To (l) make inoculation tests to determine by subsequent measure- 

 ment of lesions and by other indications the immunity or resistance 

 or susceptibility of plant species, hybrids, and varieties to fungi, 

 nematodes, toxins and other toxic chemicals, and to water-logging 

 and accompanying fermentation products; (2) discover pepper varieties 

 resistant to cucumber mosaic viruses, lima beans resistant to Rhiz- 

 octonia solani, lemon tree selections resistant to shell bark and dry 

 bark and viruses that decrease growth rate; and avocado varieties 

 resistant to Phytophthora root rot, Verticillium wilt, and Dothiorella 

 canker; (3) search for mild strains of viruses to be used for cross 

 protection or vaccination purposes; and (4) search for and identify 

 specific factors involved in disease resistance, as inhibitors of 

 fungus enzymes and dearth of thiamin in citrus varieties. 

 PI. Path. 865 



