ROOT-KNOT EELWORM. 135 



until it has reached the destructive point which has brought it under 

 consideration. 



We do not as yet know of this Eelworm as a field crop pest here, 

 but to growers under glass, the extreme difficulty of getting rid of the 

 mfestation, when once established, makes the presence of such a pest 

 serious in the extreme. 



In the paper on this Nematode by Dr. J. Kitzema Bos,* he 

 mentions that " The ground in which the Boot Eelworms have once 

 been found, commonly remains infested agriculturally, and will only 

 produce diseased plants," and in the case on which I am writing the 

 expense of removal of infested soil, and carting in what it was hoped 

 would remain clean, and also applications which it was hoped might 

 poison the pest, have met with very far from the success which could 

 be desired. — Ed. 



Amongst the details of experiment made under the direction of the 

 Entomologist of the United States Agricultural Department, and 

 recorded by Dr. Neal, I do not find that any of the applications were 

 thoroughly remedial. It is stated, however, that alkaline mixtures, 

 20 to 40 lbs. to each tree, or caustic lime, kainite, muriate and sulphate 

 of potash, or wood ashes, used several years in succession, have come 

 nearest a cure, destroying no doubt many free worms, and inducing a 

 vigorous tough growth of roots more difficult of penetration. It is 

 especially mentioned that a liberal application of the fertilizer is 

 requisite, " Not less than 3000 pounds to the acre should be used to 

 produce the required efl'ect, one-half in December, the remainder in 

 May" (J. C. N.). This of course must be taken with consideration of 

 nature of fertilizers, also of cost. 



A method which appears really to act serviceahly [where circnvutances 

 allow of its adoption) is the use of " trap plants.'^ In field cultivation, 

 as, for instance, in Continental infestation, where the Eelworm may 

 be at Clover roots, it may very likely not answer thoroughly, because 

 (as pointed out by Dr. Eitzema Bos), this kind of Eelworm infests such 

 a variety of kinds of plants, that the " trap " or " catch " plants may 

 not be a special attraction. But in growing under glass the plan 

 might be thoroughly utilized. 



The points to attend to, are to choose some plant which the Eel- 

 worms are known to be partial to, and when this has grown, to keep 

 careful watch by examination of some of the plants as to how the plan 

 is working. Firstly, whether the galls are forming ; and, secondly, 

 their condition, so that the "trap plant " crop may be cleared out, and 

 destroyed before the wormlets are sufficiently mature to make their 

 way out from the galls, and thus simply add to wormlet presence 



* ' Tierisclie yobadlinge uml NiiUliiige,' vou Dr. J. Eitzema Bos, p. 781. 



