- 8 



I will now outline my concept of an efficient spray operation 

 aimed at the objective of using less labor to apply less chemical 

 in a more carefully controlled way while stabilizing or lowering 

 pest control costs . 



Proper supervision is required. The sprayer must be calibrated 

 to deliver the proper amount of spray for each 40 feet of row space. 

 The rate of travel when spraying mature apple trees should be kept 

 at 2 mph. Spraying should be done under as favorable conditions as 

 possible, but in alternate row spraying we have made the applica- 

 tion within one day of the scheduled time. A count on the mite 

 population should be made at weekly intervals from mid-June until 

 mid-August. 



shoul 

 shoul 

 two d 

 above 

 of 5 

 sure 

 3X or 

 devel 

 6X, b 

 and c 

 about 

 speci 



Proper e 

 d accura 

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the tre 

 to 8 mph 

 have not 



4X beca 

 oping 18 

 ut at 10 

 logging 



5% of t 

 al metal 



qui pme 

 tely m 

 uf f i ci 

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been 

 use of 

 0-200 

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 in som 

 hei r c 



since 



n t is e 

 easure 

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 n most 

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 satisfa 



poor b 

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spray 

 e cases 

 apaci ty 



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ssent 

 groun 

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 left) 

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 1 pum 

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 reak 

 ssure 

 has b 

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ial . 

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and 

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 ps de 



for 

 up of 



have 

 een h 

 pumps 

 zzl e 

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A sp 

 eds 

 and a 

 drive 

 it sh 

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 apply 



the 



work 

 eated 



whic 

 discs 

 ear r 



eedome 

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the s 

 oul d d 

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 spray . 

 ed wel 

 , w i t h 

 h were 



shoul 

 a p i d 1 y 



ter or 

 3 mph . 

 ocity t 

 pray in 



this 

 to 100 



ncentra 

 Centr 



1 with 

 chemica 



d i s c h a 

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tachometer 

 The sprayer 



spray in 

 to and well 

 against winds 



psi pres- 

 tes beyond 

 ifugal pumps 

 sprays up to 



1 deposits 

 rging only 



ceramic or 



For large trees, I like airblast sprayers with a heavy duty 

 high pressure pump set at 200 psi pressure, an air delivery of 

 90,000 - 100,000 cfm, and an air velocity of about 125 mph. Most 

 of our spraying is done during daylight hours. There usually is 

 some wind to combat. One of the basic problems in using concen- 

 trates is that force is required to obtain deposit of fine spray 

 droplets in tree tops. My comparisons of medium versus large-size 

 airblast sprayers with the same air velocity have shown a signifi- 

 cant improvement in chemical coverage and deposit at any height on 

 the tree with the larger unit. I freely admit, however, that a 

 sprayer is a tool, and a combination of a relatively small sprayer 

 and a good manager can result in excellent pest control. 



In general, with the equipment indicated above, I think that 

 most growers should apply the early-season oil spray at 3X and then 

 change to 6X for the remainder of the season. In some cases, it 

 might be well to go to lOX for one or two scab sprays. However, I 

 think that the exact degree of concentration will be determined in 

 many cases by the work schedule of the employees. If the men norm- 

 ally work from 7 to 11:30 A.M., then a spray concentration should 

 be chosen which will allow the application of three or four tanks 

 within that time. 



To calibrate an airblast sprayer for the application of 3X 

 spray on mature apple trees at 2 mph, insert a pressure gauge into 

 the sprayer manifold, partially fill the sprayer with water, and 



