254 MASS. EXPERIMENT STATION BULLETIN 170. 



the "M. A. C. nozzle,"^ has been patented and placed on the market. 

 This nozzle is adapted for use with apertures ranging from one-eighth 

 inch upwards, and is adjustable so that different types of sprays may be 

 ])roduced. It is designed for high-pressure work, and is more efficient at 

 relatively close range than long distance; consequently, when used in 

 connection with the Wortliley tips an effective method of spraying results. 

 With a three and one-half to six horse-power machine it can be used with 

 one-eighth to three-sixteenths inch tips effectively, but in such cases a 

 ladder must be employed with high trees. 



The securing of competent men is also important in spraying. Any 

 reliable man of common sense can learn to spray in a short time, and 

 there should be little difficulty in securing such men if they are treated 

 properly and well paid. 



At the present time there are numei'ous types of spraying machines 

 on the market ranging from two horse power on, and costing from $200 

 to $1,200. When it becomes necessary to spray a large number of trees 

 in towns or cities, only the large size machine should be used, but the 

 large machines are rather costly for small towns mth a limited amount 

 of work to be done. 



In the case of towns Ij^ving a limited amount of work to be done, it is 

 better either to contract the work or secure a five or six horse-power 

 machine. As a rule, contract spraying of shade trees, done with small 

 hand pumps or with small machines, is quite unsatisfactory, the equip- 

 ment not being adapted to the best work at the usual contract prices, 

 especially when many large trees must be sprayed. The cost of spraying 

 large trees Avith hand pumps or small machines with the Bordeaux nozzle 

 should be at least $1..50 per tree, and few contractors take work at this 

 price. When contracts are accepted at the price of 70 cents per tree the 

 work must be slighted with the inferior equipment employed, and even 

 then it is done at a loss. With the use of large macliines and solid-stream 

 sprays, city trees have been spra5^ed for about 20 cents each, and an 

 average price in cities and towns would be from 20 to 39 cents. In one 

 instance the average price for spraying about 900 elm trees, with an 

 average diameter of 20 inches, during a period of six years was 57 cents 

 per tree; a three and one-half horse-power engine and an " M. A. C. nozzle " 

 were employed. Use was made of a ladder, but very little climbing was 

 done, and the price represents the bare cost of material and labor. Dete- 

 rioration of machinery, repairs, etc., are excluded. An outside contractor 

 should of course receive considerably more for spraying to offset the extra 

 items of expense, such as the cost of transportation, housing his men, etc. 



1 This nozzle was devised by the writer, and the patents are held by the Massachusetts Agri- 

 cultiiral Experiment Station. It is manufactured and sold by Brackett, Shaw & Lunt, 62 North 

 Washington Street, Boston, Mass. 



