226 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 17 
Furthermore, the work of soil fumigation admits of wide application to 
injurious insects as well. 
In our work in Florida we have approached the subject largely from 
the view point of the gardener and trucker. For the general farmer, 
and even for the fanner who combines considerable trucking with his 
staple crops, the cheapest and most desirable method of dealing with this 
pest is doubtless the time-honored one of rotation of crops, growing 
for two or three years on the infested land crops more or less resistant to 
the nematodes, such as corn, grains, Brabham, Iron, or Victory cowpeas, 
velvet beans, etc. But the time involved is a serious objection to one 
practicing more intensive trucking. He cannot afford to devote his 
high-priced land to the above mentioned crops with their relatively 
low return per acre, and most truck crops are seriously affected by the 
root-knot organism. To meet the needs of the trucker an endeavor 
has been made to find a quicker method of controlling the pest. How¬ 
ever, even for the intensive trucker, rotation of crops should not be 
abandoned. We have accumulated considerable evidence that there 
are among the nematodes strains which have become adapted to certain 
crops. We have repeatedly observed that when a crop of lettuce, for 
instance, heavily infested with root-knot, is harvested from the land, 
the land can at once be set out to celery with comparatively little 
damage, whereas a second crop of lettuce on the land is seriously 
affected. These observations are in direct contradiction to those 
obtained by Bessey on this subject and will need careful verification by 
pot experiments before we can consider the question settled. 
In all our work commercial control rather than complete eradication 
has been our aim. Florida soils, unless newly cleared, are so universally 
infested with nematodes that even if we should completely eradicate 
the pest from a piece of ground it would be very quickly re infested from 
surrounding plots, as is newly cleared land. Our aim, therefore, has 
been rather to reduce the nematodes to such an extent that the farmer 
is able to grow a susceptible crop on the land during the next trucking 
season. This is much less expensive than would be complete eradication. 
Our work has been largely along two lines, starvation and soil fumi¬ 
gation. 
Starvation 
The Florida trucking industry has a favoring circumstance in the 
fight against nematodes in that it is limited to the fall, winter, and spring 
months, leaving the land unoccupied during the summer, the most 
active season for nematodes. Formerly it was almost universal to 
