196 Pecan-Growing 



pecan orchard within the period in which spraying has been 

 found to be effective. Only a motor-driven spray pump can 

 be relied on for bearing pecan trees. Orchards of medinm- 

 sized trees, and limited in area, may be sprayed efficiently 

 with an ontjfit ranging from four to six horse power. Large 

 commercial orchards require high power sprayers of eight to 

 ten horse power. The low power machines are practically 

 worthless in a pecan orchard after the trees reach the bear- 

 ing age. 



The high capacity spray outfit has no tower. The operator 

 sprays from the ground or from the top of the tank. The spray 

 rod will not do effective work for more than about twenty 

 feet above the ground and for this reason it has been almost 

 completely supplanted by the spray gun. The latter works 

 best on a high power machine so that effective spraying can 

 be accomplished from fifty to sixty feet above the ground. 

 (See Plate XI).. 



A ten horse power outfit has the capacity for operating two 

 guns at one time. The output of spray solution will average 

 about eight gallons a minute. The medium-sized outfits can 

 operate only one spray gun, while the small or low power 

 machines having from one to two horse power, are not recom- 

 mended for the use of a spray gun. A pressure of 250 to 300 

 pounds should be maintained to use a spray gun satisfac- 

 torily. It is, therefore, necessary to employ only the best 

 grade of high pressure spray hose connected with long-stem 

 couplings to prevent blowing apart when subjected to high 

 pressure. 



The wheels of the tank truck should be rather high and 

 have broad tires in order to lessen the draft over soft and 

 uneven ground when the tank is full of spray solution. A 



