18 MARKET NURSERY WORK 



rafters or any unoccupied spot that catches the full rays of the 

 sun, taking care not to overdo it. The fumes are imperceptible 

 to us, but they are sufficient to set up a barrage which no fungus 

 can pass alive. The process should be frequently repeated. 

 We submit that both these preventives are exceedingly simple, 

 they are clean, they are easily handled, yet by their use we have 

 completely banished the cladosporium, the black spot, and 

 even "stripe" from houses which for years had been badly 

 infected. 



But fungoid diseases are not the only ones from which the 

 tomato suffers, for there are a legion others equally inimical 

 to its well-being. The worst of them attack the roots, and their 

 presence is only detected when the leaves are hanging limp 

 and disconsolate. Of this nature is " club root," a most 

 baneful disease, caused by a minute worm which, penetrating 

 the root, causes a swelling into large nodules, completely pre- 

 venting its function of feeding the plant so entirely dependent 

 upon it. Nor is it easy to trace the cause of it with any degree 

 of certainty. The worm itself is an effect and not a cause, 

 for it is produced by conditions which favour it, though what 

 those conditions are we cannot determine. We only know 

 that " club root " may be found in rich soils as well as in poor 

 soils ; in light land as in heavy ; in heated houses, in cold 

 houses, and in the open air. 



For our purpose, the immediate cause is this tiny eel-worm, 

 which, being an insect, cannot be invulnerable. It should be 

 and undoubtedly is susceptible to treatment by the right form 

 of soil insecticides. There are several preparations on the 

 market advertised to prevent or to kill " club root," but we 

 will not undertake to say that there is no room for their further 

 improvement. Doubtless, further research and further experi- 

 ment will furnish us with a weapon whose efficacy is beyond 

 doubt. Our own method is to use one of these preparations, 

 then heap some new soil about the affected plants, and do all 

 we can to induce them to make new roots from the collar as 

 quickly as possible. 



Then we have the " sleeping disease," the results of which are 

 so similar to " club root." This is caused by an enemy microbe, 



