24 BULLETIN 851, U. S. DEPARTMENT OF AGRICULTURE. 



Spraying is perhaps the most important of all maintenance labor. 

 Practically all orchardists in the five counties in which this investi- 

 gation was made do some spraying each year. From three to six 

 applications per season are made by the commercial growers. The 

 importance of this operation is shown by the bare fact that the labor 

 cost is $6.80 per acre and $8.66 for material per acre, making a total 

 of $15.46, or 13 per cent of the total net cost of production. The 

 tree cost for spraying is 4A cents. This, however, does not include a 

 machine charge. 



Gasoline-power sprayers are used by practically all growers. This 

 outfit usually consists of a 2§ to 3^ horsepower engine, with a 100- to 

 300-gallon tank. The machine and tank are usually hauled on low 

 truck wagons. Either a crew of two men and two horses, or of three 

 men and two horses, is used in spraying. AYhere two men spray, one 

 ordinarily tends the engine and sprays from the ground, while the 

 other man drives and sprays from the top of the machine or tower. 

 Where three men are used, one man drives, and the other two do the 

 spraying; sometimes one of these men is in the tower. Two leads of 

 hose, usually about 50 feet in length, with pipe or bamboo spray 

 poles, are used. The pressure is usually from 125 to 250 pounds. 

 Many outfits carry spray towers, for without a tower it is impossible 

 to make a thorough spraying of the tops of some trees. 



Within the last year or two a new type of outfit, with considerably 

 more power than that of the old type, has been put on the market. 

 Many fruit growers believe that this system will revolutionize spray- 

 ing. 



Dusting with a mixture of sulphur and some form of insecticide 

 has been tried in this part of the country experimentally, and to 

 some extent by growers, during the last three or four years. 



DORMANT SPEAY. 



i; Dormant spray " usually refers to spraying prior to any tree 

 growth, during the months of March and April. However, within 

 the last few years there has been a tendency to delay this early spray 

 until the fruit buds begin to show the tips of the first leaves, or even 

 as late as when the leaves are one-fourth to one-half inch in length. 

 This spray is termed " delayed dormant " or " semi dormant." At the 

 time of this investigation no particular distinction was drawn between 

 £he growers who made a dormant and those who made a delayed dor- 

 mant spray. The delayed dormant spray is perhaps the one most 

 generally used. The exact time of application, of course, will vary 

 with the season; it is ordinarily applied during the latter part of 

 April or early in May. Two hundred and six orchardists, or 91 per 

 cent of the total number considered in this investigation, applied the 

 dormant spray. Lime-sulphur, 32° Baume, strength, 1 gallon to 8 



