10 



MASS. EXPERIMENT STATION BULLETIN 351 



Table 3. — Results of Other Investigators with Formaldehyde as a 

 Soil Disinfectant 



Literature 

 Citation 



Dilution and 

 Application per 

 Square Foot 



Number of cc. 

 per Square Foot 



Commercial Water 

 Formaldehyde 



Resulting Control of 

 Damping-ofT 



Johnson (54) 

 Clayton (20) 

 Johnson (54) 



Brien and 

 Chamberlain (13) 



Weindling and 

 Fawcett (95) 



Brien and 

 Chamberlain (13) 



Guterman and 

 Massey (40) 



Wilson and 

 Tilford (100) 



Weindling and 

 Fawcett (95) 



Guterman and 

 Massey (40) 



1 :50, 2 quarts 



1 :50, applied to soil 

 saturation 



1:75, 2 quarts 



1.0 percent solution, 

 1.33 quarts 



6.0 percent dust, 

 3 ounces 



0.83 percent solution, 

 1.33 quarts 



Applied 12 to 24 hours 

 before seeding. Soil 

 well watered after 

 seeding 



6.0 percent dust, 1.5 

 ounces — the common 

 recommendation for 

 dust 



6.0 percent dust, 

 1.5 ounces 



Applied immediately be- 

 fore seeding. Soil well 

 watered after seeding 



37.8 1855 Prevented infection by 



Pythium and Rhizoctonia 



Prevented infection by 

 Rhizoctonia 



25.0 1868 Did not prevent infection 



by Pjthium and Rhizoc- 

 tonia for more than 15 

 days 



13.0 1246 Prevented infection by 



Pythium and Rhizoctonia 



13.0 Prevented infection by 



Rhizoctonia 



10.5 1249 Did not prevent infection 



by Rhizoctonia, but some- 

 times controlled Pythium 



7.1 39 Controlled damping-off as 



well as formaldehyde dust 



Killed Pythium: also the 

 mycelium but not the 

 sclerotia of Rhizoctonia 



Failed to prevent infection 

 of citrus seedlings by 

 Rhizoctonia 



27-18 Controlled damping-oflf as 

 well as formaldehyde dust 



Acetic acid is sometimes less effective against Rhizoctonia than against 

 Pythium, and there are indications that formaldehyde, too, may be less effective 

 in preventing damping-off caused by Rhizoctonia than that which is caused by 

 Pythium. Thus Wilson and Tilford (100) observed that the formaldehyde dust 

 treatment which kills Pythium (and certain other fungi) in soil also kills the 

 mycelium, but not the sclerotia, of Rhizoctonia; and Weindling and Fawcett 

 (95) concluded that it may be necessary to use 3 ounces of formaldehyde dust 

 per square foot (instead of 1.5 ounces as commonly recommended) to prevent 

 infection of citrus seedlings by Rhizoctonia. Brien and Chamberlain (13) also 

 found that an application of formaldehyde which was at least partly effective 

 against Pythium was completely ineffective against Rhizoctonia. Hartley (43), 

 too, noted that formaldehyde does not always rid soil of Rhizoctonia, and Peltier 

 (73) was not altogether successful in protecting carnations against this fungus 

 with formaldehyde. 



