14 NEMATODE GALLWORM ON. POTATOES, ETC:., IN NEVADA. 
S worm, and garbage 
containing peelings 
of diseased potatoes 
is also a prolific 
source of infestation. 
The use as seed 
of any infected 
potatoes is to be 
strongly condemned. 
No effort should be 
spared to locate all 
infested fields in a 
district where the 
nematode is known 
to occur, and seed 
Fic. 19.—Roots of okra, show- potatoes should be 
ing the enlargements caused secure d from fields 
by the gallworm. The nem- : 
atodes producing this dis- known to be unin- 
ease are to be found in the fested or, better still, 
root enlargements. (After . 3 ; , 
J. C. Neal.) from a region where, 
Fic. 20.—Roots of cucumber, showing en- 
largements caused by the gallworm. 
Nearly all other common garden plants 
are similarly attacked. There are many 
thousands of the worms in the nodules 
upon such a root system. (After Kati 
Marcinowski. ) 
because of adverse climatic 
conditions, the nematode 
is unknown. 
A thorough inspection 
should be made of all fields 
ff / Fig. 21.—Roots of lettuce, showing 
@ . . . 
enlargements caused by thegall- in each district where the 
4 worm. Many plants are killed RB | : t a t 
fi in the seedling stage by the nematode 1s sous pe € 0 
gallworm. (After Kati Mar- occur, and allinfested fields 
cinowski.) 
should be devoted to crops 
which the nematode does not attack. There are 
many plants besides the potato which are susceptible 
to nematode injury, and these should never be 
planted or allowed to grow in fields where the gall- 
worm is found. There are anumber of crops that are 
not attacked by this parasite, and these only should 
i@ims 9:5] 
