6 MARKET NURSERY WORK 



ENEMIES 



Possibly the most difficult thing in the cultivation of plants 

 under glass is that of keeping them free from a swarm of 

 enemies. Growing, as they do, under unnatural conditions, 

 they are peculiarly susceptible to the attacks of various diseases 

 and insect pests which the said conditions encourage. 



Once they are permitted to gain a foothold it takes a strenuous 

 effort to eradicate them. We have seen disease spread from 

 plant to plant in a tomato house so that within twenty-four 

 hours not a single plant could be found entirely free. 



Green fly, mealy bug, thrip, scale, red spider, every one of 

 which is a hideous foe, have an uncanny way of appearing 

 from nowhere. A too dense humidity, a burning aridity, a 

 stagnant atmosphere will bring them out in battalions and 

 breed them in such quantities that the work of extermination 

 becomes exceedingly difficult and costly. As we hope to show, 

 it is far easier to prevent attacks than to cope with them after- 

 wards. Not only is it wise to make use of well-proved deterrents, 

 but, knowing the dangers that are always present and potential, 

 we are ardent advocates of the hygienic treatment of plants. 

 Hygiene has done much to ameliorate the conditions under 

 which the human race exists ; it has done as much for animal 

 life, and we know that it can prove as beneficent to plant life. 

 It is possible to avoid that excessive humidity ; to prevent 

 that searing aridity ; to cleanse and purify that stagnant 

 atmosphere, and thus remove their baleful influences. The 

 charge-hands who neglect these essential safeguards are not 

 fit to be entrusted with the care of the houses. If they do 

 so through ignorance, they are proved incapable ; if they do 

 so through negligence, they should be discharged. 



CLEANUNESS 



Absolute cleanliness is the first rule of hygiene. A dirty 

 house is a breeding pen for everything that is bad. A hothouse 

 should always be clean, not only because it is more pleasing 

 to the eye, but because it is essential to the health of the plants. 

 Every second year the inside rafters should be given a coat 

 of good oil paint. The brickwork should be limewashed every 



