J 56 Journal of Agriculture, Victoria. [11 March, 1918. 



French vines — 5 feet x 5 feet, as a rule, tkougli occasionally Ih, feet x 

 4 feet — in other words, from two or three times as many vines per acre 

 as in our vineyards. 



The following are some of the main requirements which must be 

 filled by an efHcient vineyard traction sprayer : — 



Easij adjustahility of nozzles, and of the boom to which these are 

 affixed; this is amply provided for in the Perras machine. (See Figs. 

 16, 17 and 18). The arrangement must be such that the number and 

 position of the nozzles can be varied in numerous ways. The adjust- 

 ment will want to be quite different for the first spraying to what 

 would be required for subsequent ones. The arrangement shown in 

 Fig. 19 would be more suitable for early than late spraying; by fixing 

 the two nozzles fairly low down, and giving them an upward cant, 

 under-side spraying, as recommended by some, for the first treatment, 

 can be realized. 



Sufficient imm'p power. — This must be such as to provide ample 

 pressure. It is the high pressure obtainable with motor-driven pumps 

 that makes them so popular with orchardists. 



Pressure and output must he adjustable. — The second of these depends 

 largely on nozzle aperture, but not entirely so; it also depends on pres- 

 sure. The same output, for example, would be obtained with small aper- 

 ture and high pressure as with a larger a^ierture and lower pressure ; the 

 spray would be much finer in the former case. Though fineness of 

 spray is generally most desirable, there are cases in which it may be 

 excessive. In windy weather, for example, an exceedingly fine spray, 

 excellent on a calm day, would be too easily blown away and much of it 

 Avasted by wind. Under such circumstances, a rather coarser spray, ob- 

 tainable with larger aperture and lower pressure, Avould be more suitable. 

 In several nozzles, the aperture is contained in a small, removable metal 

 disc, which can be quickly changed. Instead of one large nozzle at any 

 given point, it may be preferable to use two or more small ones. 



Agitation must be sufficient to keep sediment constantly in suspension. 



Zyt^/i^?ie5S.— Unnecessary weight must be eliminated wherever possible. 

 It is in a wet season that spraying is most vitally necessary; in a season, 

 in short, when the soil of the vineyard is worst adapted for vehicular 

 traffic. The quantity of liquid carried must be considerable, so as to 

 reduce loss of time entailed by too frequent filling of the reservoir; this 

 should have a capacity of at least 50 gallons — say, enough to spray an 

 acre.* In this alone Ave have a load of 500 lbs., to Avhich must be added 

 the weight of pump, air chamber, &c. 



Solidity. — A most necessary condition in all machines of the kind. 

 Though lightness is essential, solidity must not be sacrificed to it. 



Adaptahility to the distance between the roivs.- — A machine suited for 

 rows 10 feet apart Avould be useless in the narroAver rows (5 to 6 feet in- 

 tervals) of cooler districts. It is, nevertheless, advantageous to have as 

 wide a wheel base as the interval between the roAvs Avill permit, so that 

 the sprays will be deflected from their proper position as little as possible 

 in the necessarily rough ground of a A'ineyard. In some American 

 machines the distance betAveen the Avheels is adjustable. 



* Tliis is an averagi- : the first spraying will take less and the later ones more than this quantity. 



