58 EXPERIMENT STATION. [Jan. 



Influence of Lime on Eel Wokms {Heterodera 

 radicicola (Greef.), Miill.). 



BY G. E. STONE. 



Various writers in florists' and gardeners' jonrnals have for 

 years advocated the use of lime for destroying eel worms in the 

 soil. In one of our earlier pnblications^ we have given the 

 results of tests made of a large nnmber of substances, among 

 others lime. Our former as well as our more recent experiments 

 have shown that lime has little or no effect upon eel worms, as 

 was evident from the fact that we were able to keep them alive 

 in a saturated solution of lime water for some days. When 

 sugar was added to the lime, making saccharate of lime, the 

 results were quite diiferent, the latter solution killing them. 

 Undoubtedly the application of lime to greenhouse soil improves 

 it by modifying its acidity, but eel worms will thrive in soils 

 which are not acid. 



For many years we have been experimenting with boxes of 

 soil contaminated with eel worms, and have treated them in dif- 

 ferent ways. In one experiment, started Oct. 8, 1901, and 

 continued to 1907, two boxes were used, having the dimensions 

 of 5 by 5^ by 14 inches. Both boxes were filled with soil con- 

 taminated with eel worms. The soil in one box was treated with 

 about 200 grams of lime, thoroughly incorporated. The other 

 box was treated with 2,000 cubic centimeters of water contain- 

 ing 100 grams of sugar and 100 grams of slaked lime. The 

 results of these experiments, which extended to 1907, are as 

 follows : — 



The first three crops showed abundant eel worm galls on the 

 roots. Then 60 grams of lime were added to the box con- 

 taining lime, and incoriiorated with the soil. Seven subsequent 



1 Bulletin No. 55, Hatch Experiment Station, 18US. 



