SPRAYING PROBLEMS 151 



near perfection as possible with one exception, and 

 that is, that all of them give off a circular ring of 

 spray and leave the centre untouched, so that it is yet 

 open for someone to construct a nozzle which will 

 also hit the centre and give an even coating over the 

 area at which the spray is directed. 



Many new developments of the spraying machine 

 are foreshadowed, and possibly one of the first types 

 to appear in the near future, now that motor tractors 

 have been generally adopted, will be a tractor sprayer. 



The tractor sprayer will consist of pumps and tank 

 mounted together on a light motor having suitable 

 travelling wheels, the pumps being driven from the 

 engine and the tank fitted with an automatic agitator 

 to keep the mixture well stirred. This machine could 

 be fitted with a set of delivery pipes somewhat like 

 the present hop-washer, so that the trees or plants 

 could be sprayed as it travels along between the rows, 

 or the same machine could be used in connection 

 with several short lengths of hose with branches and 

 nozzles for hand-spraying purposes, the machine 

 being driven from tree to tree as each is thoroughly 

 sprayed. 



For potato spraying it is quite likely that some form 

 of motor will be evolved if the difficulty of steering 

 can be properly overcome. With such a machine it 

 would be possible to deal with a much larger acreage 

 in the same time. 



Let us refer to the potato disease once more, to see 

 why it is necessary to spray universally. After the 

 disease had attacked the foliage, the old story was that 

 the fungus passed down the haulm and reached the 

 growing tubers. This view is proved to be incorrect. 

 The myriads of spores formed on the foliage are 

 scattered by the wind not only on the neighbouring 

 plants but on the ground. Should there chance to be 



