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through a lens, and the result is that the tissues of the leaves and 

 fruit immediately under the droplet are heated so much as to lead in 

 conjunction with the chemical action of the fungicide, to weak or 

 broken skin, and after that to an attack of Gloeosporium. 



While on this subject I would like to again emphasise the importance 

 of a fine spray quickly applied. This is a matter upon which I have 

 insisted for a long time without, as it appears to me, the result being 

 what it ought to be. I have just alluded to the danger attendant 

 upon the application of a spray at a time followed by strong hot sun- 

 light ; but such danger would be comparatively little if the spray were 

 as fine as it ought to be. If the droplets of spray are so fine as to be 

 almost invisible, their effect in conjunction with the hot sun would be 

 trifling for two reasons. In the first place they would be so small 

 that they could not collect enough heat to be injurious, and in the 

 second place they would evaporate so quickly that they would be gone 

 before they had time to collect sufficient heat to do any damage. 



On other occasions I have given the strongest reasons why a spray 

 should be applied in a very fine state of subdivision, namely, that 

 under such circumstances the spots of poison are greater in number 

 and the distances separating them are less, and in -consequence of this 

 the germinating spores of fungi are more likely to run against the 

 poison spots and thus be killed. Of course, it would be useless to 

 have the spray fine if the plants are " drowned " with fungicide. 

 The idea seems to prevail with some users of fungicides that the object 

 of applying a spray is to wash the disease off the plants. Nothing could 

 be farther from the truth. The object of spraying is to place upon the 

 leaves and other parts of the plant small spots of poison, and to place 

 them so close together that any germinating fungi will soon come into 

 contact with one of the spots and, absorbing some of the poison, be killed. 

 A few simple observations will convince anyone that in a certain sense, 

 that is to say after a certain point in the spraying is reached, the more 

 spray applied the less good is done. Any orchardist that has not 

 already done so should try the following simple experiment. 



Spray a few leaves with Bordeaux mixture for a few seconds with 

 as fine a spray as possible, using a well-made mixture and a high 

 pressure. Simply pass the nozzle of the sprayer over the leaves once. 

 Allow the leaves to dry, and meanwhile spray another similar lot of 

 leaves for a longer time, observing how after the first few seconds the 

 droplets of the spray collect together into larger and larger drops, 

 until at last they roll off the leaves on to the ground. This latter 

 kind of spraying is of little value, for if the leaves sprayed in this 

 manner be allowed to dry, and then be compared with those sprayed 

 as at first directed, it will be found that the leaves sprayed with a 

 small dose have retained the larger amount of the fungicide, and are 

 therefore better armed against the germinating spores of fungi. 



I even go so far as to advocate a double application of fungicides 

 in the following manner, and I would like to add that my opinion in 

 this matter is formed after careful laboratory tests, followed up by 

 corroborative field tests : Go over the work rapidly, never allowing 

 the nozzle of the sprayer to play for more than a second or two upon 



