CONFERENCE ON SPRAYING OF FRUIT TREES. 



341 



to wrong mixing to find the trees burnt, or else the mixture used at a 

 strength insufficient to kill, and so much valuable labour lost. 



The pumps used should be as far as possible unlikely to go wrong, 

 and, should they do so, as simple as possible to dismount and repair. To 

 this end ball valves ought to be used in preference to clacks or mushroom 

 valves. It should be possible to get at the mouth of the suction hose to 

 clean it, and this of course should be covered with close mesh wire gauze. 

 The pump should have an air chamber for maintaining continuous 

 pressure, by which it ought to be possible to get from 60 to 100 lb. a 

 square inch. Whatever form the plunger takes it should, if packed, be 

 easily renewed as the wearing with lime and caustic washes is considerable, 

 and sometimes the pump will give out quite suddenly from this cause. 

 All taps used should be well ground in, and have large passage ways, or 

 they are liable to choke with heavy washes. As to the form of nozzle it 

 is impossible to speak with any certainty, as there are so many different 

 forms, all equally good, some for one job, and some for another. I have 

 found those the best in which a spiral twist is given to the liquid by some 

 device or another before it comes to the final opening, which can be large 

 or small as desired. This spiral twist given to the liquid gives better 

 results than if it were forced direct through the same aperture. 



Whatever form of jet is used, and whatever pump forces the liquid, 

 it must be possible to get a fine mist-spray with a good pressure behind 

 it. Washing as one understands it from hop washing is of very little, if 

 any, use in fruit-tree spraying, and a good light spray with power behind 

 it has a more penetrating effect, and but little of the liquid is lost, com- 

 pared with the loss when there is a copious flow with little pressure 

 behind it. 



Now as to the form of pump to be used, and the way it is to be 

 mounted. 



It seems to me that except for small places and small trees the 

 knapsack machine is not big enough, and is next to useless save for a tree 

 here and there. It does not carry enough, and it is not possible to throw 

 the liquid far enough when one has to direct the spray and the pump too. 

 Fancy using a two-gallon knapsack on a tree that requires a 40-stave 

 ladder to pick it. It is like attempting to put out a big fire with a 

 lady's scent-spray. There is not only the drawback of want of power, 

 but owing to carrying so little they require filling so frequently in long 

 lands necessitating as many carriers of fluid as pumpers to keep the latter 

 even moderately busy when the trees are of any size. Personally I think 

 in large gardens 40 gallons is the lowest capacity that can be used with 

 profit. In large grass orchards, or those where there is no undercrop, 

 a holder up to 100 gallons can be used, but particular care must be taken 

 to keep the liquid in such a large machine well agitated. This is a 

 most important point in spraying, as without thoroughly effective agita- 

 tion the spray fluid is likely to be very weak at one time and over-strong 

 at another as the active component either rises or sinks in the water. 



All spray fluids are of course diluted to a safe strength with water, 

 and all, no matter what kind they be, have a tendency to separate when 

 in the machine, either like the emulsions to rise and form an oily curd 



