COST OF SPRAYING 47 



precaution indicated above, the spray has to be made as 

 fine as possible. A fine mist is all that is necessary to 

 produce a thorough wetting of the leaves. When the 

 spray is coarser, the solution soon begins to drip from the 

 leaves and is wasted. 



To get the maximum effect out of resin washes, it 

 appears to be necessary to have the spraying done during 

 the warmer hours of the day. It has been invariably our 

 experience that spraying done during this period of the 

 day is more effective than that done in the morning or 

 evening. 



The cost of spraying varies with the age and size of 

 the trees, the number of trees per acre, the degree of 

 infestation and the facilities that exist for spraying, 

 such as the supply of water and labour. All these factors 

 have to be taken into consideration, as they vary from 

 localit}' to locality and from estate to estate. Therefore 

 it is possible to give only approximate figures for the cost. 



The number of plants per acre varies from 1,200 to 

 1,700. The amount of solution reqiiired for each plant 

 depends on the age and spread of the tree. The labour 

 required also increases with the age of the trees. In 

 spraying young plants, on the other hand, there is likely 

 to be a certain amount of wastage of the solution. 



In the year 1914-15, 32,082 plants were sprayed 

 under departmental supervision, with 2,890 gallons of the 

 mixture or roughly with 13 cwt. of the fish oil resin 

 soap. This works out at 11 trees per gallon. One pound 

 of the spray soap would spray roughly : — 



Plants of 9 years and older ... ... 15 



,, 4 to 8 years ... ... ... 20 



1 to 3 „ ... ... ... 25 



The number of plants sprayed by one cooly in a day 



was found to be : — 



75 for plants of 9 years and upwards 

 120 „ 4 to 8 years 



200 ,, 1 to 3 years 



The number of plants per acre planted may be taken 

 as 1,500 on an average. 



On the basis of these figures the cost of spraying 

 .per acre is as shown on the next page; — 



