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Table 1. Number of trees to cover with 100 gallons or with 1 gallon of spray 



solution when applying at the rate of 100 gallons per acre and spraying 

 the stated number of feet from the tree trunk on all four sides of the 

 tree. 



Distance sprayed from 

 middle of the trunk 



3 feet 



4 feet 



5 feet 



6 feet 



7 feet 



8 feet 



Many of the herbicides used for weed control are wettable powders that form 

 suspensions rather than true solutions. If agitation is not sufficient, the 

 materials will settle out and result in a higher concentration of herbicides in 

 the bottom of the tank. This, in turn, could cause serious injury when the mixture 

 is applied around the trees. 



Mechanical agitation cannot be provided as easily as jet agitation. Jet 

 agitators have been developed which can be connected to the pressure line between 

 the pump and the by-pass valve. The agitation consists of a head with three 

 orifices from which streams of spray solution are expelled. It is suspended by a 

 hose to the bottom of the tank where the expelled streams agitate the spray 

 suspension. 



Herbic:fdes should not be applied with a high-pressure spray rig unless it 

 is modified. The equipment should have an operational pressure of 30 to 40 

 pounds per square inch. Low pressure and 1ot7 gallonage rates help avoid 

 forcing the spray into the soil - a common cause of herbicide injury. 



There are two basic types of general farm sprayers - boomless and boom 

 equiped. Either of these is available with a variety of pumps and carriers and 

 can be tractor or trailer mounted. The boom sprayers in common use would have 

 to be modified for orchard grasF control because of the limited area to be covered. 



He rbicid es 



The chei lical weed control recommendations for 1963 are given in Table 2. 

 The table is for the convenience of the reader but the information -contained is 

 necessarily brief. For further information read the notes which sunriiarizes the 

 weed control trials conducted in 1962. The lower dosage rates given in the table 

 may result in satisfactory weed control and gives a greater margin of safety. For 

 the most satisfactory results apply the foliage-active herbicides when the grass 

 is 6-12 inches in height. 



