RECOMMENDATIONS. 89 



Carbonic-add-gas sprayers. — Carbonic acid is employed as power in a similar manner 

 to compressed air. It is, however, somewhat more expensive than either horsepower 

 engines, gasoline engines, or compressed air. More or less difficulty sometimes occurs 

 in procuring the drums of gas, which have to be obtained from large cities where this 

 gas is manufactured. Yet there are many of these outfits in use and giving good 

 satisfaction. 



Hand pumps. — Where but limited areas of vineyard are to be treated quite effect- 

 ive work may be done with a pump operated by hand to treat vines, and in gardens 

 or places where it is impossible to drive a cart a knapsack sprayer may be used. For 

 larger areas, however, it will be found more economical to use power outfits. 



The care of spraying apparatus. — For the successful operation of spray pumps it is 

 highly desirable that the working parts be made of brass, since iron is acted upon 

 by Bordeaux mixture. It is also important that the pump be so constructed that 

 packing can be conveniently removed and replaced. Each time after the pump is 

 used a few pailfuls of water should be run through the pump, hose, and nozzles to 

 remove all of the spray mixture so that sediment in the mixture may not dry up and 

 clog the valves and nozzles while the machine is not in use. If this precaution is 

 taken much annoyance may be avoided when the machine is next put in operation. 



Nozzle adjustment. — Practically all of the power sprayers are equipped with adjust- 

 able nozzles attached to a vertical rod firmly fastened to the sides of the tank, usually 

 at the rear end of the machine. There are usually two or three of these nozzles set 

 horizontally to throw the spray into the side of the vines. In addition to these hori- 

 zontally directed nozzles, the uppermost nozzle 

 should be carried out over the top of the trellis and 

 directed downward to insure the covering of all the 

 foliage on the top of the trellis (PL X, figs. 2, 3), 

 since it is upon the new growth developing at the top 

 of the trellis that the beetles are likely to do much 

 feeding, especially after the lower foliage has been 

 thoroughly covered with a spray mixture. 



Nozzles.— Nozzles of the Vermorel type are the 

 kind in general use for vineyard spraying and pro- 

 duce a fine mistlike spray which is so necessary for ^^^- ^^-"^ ^^^^® nozzle of the cy- 

 effective work, and for this reason they are more 



desirable than nozzles of the Bordeaux type, which throw a heavier, fan-shaped 

 spray. The chief drawback with the ordinary Vermorel nozzles lies in the rapid 

 wearing out and enlarging of the opening of the cap, resulting in a coarse spray if 

 allowed to become too much worn. More recently larger nozzles of the Cyclone type 

 (fig. 31) have come into general use, especially where high pressure with power 

 machinery is used. These nozzles throw a larger cone of spray, have steel disks for 

 caps, which can be removed when the opening becomes much worn, and possess 

 the added advantage of not clogging so readily as the smaller Vermorel nozzles. 



RECOMMENDATIONS. 

 DESTRUCTION OF THE ADULTS OR BEETLES. 



The beetles of the grape root-worm feed upon the upper surface 

 of the leaves of the grapevine, and may be poisoned by thoroughly 

 spraying the foliage of the vines with an arsenical. The first poison- 

 spray application should be made as soon as the first beetles are 

 found upon the vines. Our observations indicate that the beetles 

 feed much more freely immediately after emergence from the soil 



