54 Diseases of Truck Crops 



and Pythium in infected beds. It is doubtful, 

 however, if this treatment will entirely eradicate eel- 

 worms from infested soils. The method is as fol- 

 lows: the beds are thoroughly prepared in the usual 

 way, and then drenched with a gallon per square 

 foot of formaldehyde solution composed of one pint 

 of commercial formaldehyde (40% pure) to thirty 

 gallons of water. The solution should be put on with 

 a watering can and distributed as evenly as possible 

 over the bed, so as to wet the soil thoroughly to a 

 depth of a foot. It will, in most cases, be necessary 

 to apply the solution two or three times, as the soil 

 may not absorb the full quantity of the liquid at one 

 time. After the treatment the beds should be cov- 

 ered with a heavy burlap to keep in the formaldehyde 

 fumes for a day or two, and then aired for a week 

 before planting. Stirring the soil at once would help 

 the escape of the fumes. Formaldehyde may be 

 bought in any drug store 40% pure. 



Steaming. This method of treatment is far supe- 

 rior to any other yet evolved. For seed beds on a 

 large scale the inverted pan method is the best. This 

 was first devised by A. D. Shamel of the U. S. De- 

 partment of Agriculture. The boiler must be able to 

 generate a pressure of not less than eighty pounds, 

 which should be maintained for at least one and a 

 half hours. In setting a pan the rim is sunk into the 

 soil of the seed bed, to a depth of two to three inches, 

 to make the inclosed chamber steam tight. In 

 heavy soil, trenching may be necessary. It is also 

 advisable to put a heavy weight on the pan when the 



