48 ROOT-KNOT AND ITS CONTROL. 



The mixture was applied with the hose connected to a force pump at the rate of 4 

 pounds of formaldehyde to 50 gallons of water, the treating of 15,000 plants requiring 

 200 pounds of formalin, worth about 18 cents a pound, making the treatment quite 

 inexpensive considering the result. 



Since this experiment this method has been tried in a number of 

 places and with success where the proper precautions were taken. 

 Doubtless other plants might be treated similarly, but the method 

 should be tried with caution, even for roses, until it is ascertained 

 that the plants will not be killed. 



MISCELLANEOUS. 



Plants for wliich the formaldehyde treatment can not be used can 

 often be benefited by the following treatment: Remove them from the 

 soil, wash the roots clean, and cut away every diseased root, burning 

 them. Top the plant to correspond with the amount removed from 

 the roots and plant in nematode-free soil. Such severe treatment is 

 too injurious to some plants, and about all that can be done then is to 

 give them plenty of well-aerated soil mth an abundance of f ertihzer, so 

 as to stimulate root growth to more than counterbalance the roots 

 that are reduced in value by the entry of the nematodes into them. 



It is possible that by transplanting diseased plants to stiff clay soil 

 the number of nematodes will be so reduced that a subsequent trans- 

 plantation to more suitable soil will find them free from the disease. 



On purchasing rooted plants, unless they come from a place known 

 to be free from root-knot, it will always be best to put them into a 

 quarantine bench for several montlis. If at the expiration of tliis 

 time they show no signs of the trouble, they can safely be removed to 

 their permanent quarters. Of course the soil in the quarantine bed 

 must be renewed whenever it becomes infested with the nematodes. 



Moderate quantities of soil can be freed from the pest by putting 

 it at the beginning of winter in a place where it will be exposed to the 

 cold and subject to drying out at the same time. Thus, it can be 

 thrown upon boards in a comparatively thin layer. The boards wUl 

 keep the nematodes from passing downward into the ground as the 

 soil dries out. At the same time the boards keep the moisture from 

 the soil beneath from passing by capillarity up into the soil from the 

 beds. The continued drying and freezing, especially if the soil be 

 occasionally s'tirred, is fairly eft'ective in killing off the nematodes. 



CONTROI. OF ROOT-KNOT IN THE FIELD ON PERENNIAL CROPS. 



The treatment of perennial crops in the field is of a greatly different 

 nature from that of plants in the greenhouse, cold frame, or seed bed, 

 for a process that could be applied with profit to such valuable soil 

 as that in greenhouses, etc., might, indeed mostly does, prove too 



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