Page 6 



BETTER FRUIT 



August, 1921 



pounds with two guns operating, provided 

 the discs arc cut down fine enough. How- 

 ever, in cutting down these openings the 

 actual carrying properties of the spray is 

 materially limited and as a result the tops 

 of the trees suffer, especially so in sections 

 inclined to be windy. Guns so equipped 

 with fine discs are usually handling no more 

 than 2Y2 gallons of spray per minute. This 

 is an uneconomical unit, as the operator can 

 use much more material satisfactorily and a 

 spray of this nature is one with no "kick" 

 behind it. If larger openings are used in 

 the discs the spray from this small outfit 

 becomes coarse and stream-like, due to lim- 

 ited pump capacity, and where employed is 

 usually associated with very poor success with 

 insect and disease control. At no time 

 should more than one gun be used on a 

 spr.iyer of this type. 



JUST what the economical unit to employ 

 in the case of the output from the spray 

 gun has not yet been definitely estab- 

 lished. These requirements would probably 

 vary in trees of different sizes; it being 

 possible to use more spray per minute per 

 gun with economy on very large trees than 

 could be done on small trees. The writer's 

 observations indicate that about 5 gallons 

 per minute per gun at 300 to 325 pounds 

 pressure is a unit that can be used to great- 

 est advantage. Some growers have been 

 noted using more spray than this per minute, 

 but usually their operations are accompanied 

 with considerable waste of material; 5 gal- 

 lons per minute properly applied keeps a 

 man busy, especially so with trees of mod- 

 erate size. Nevertheless, much ground is 

 being covered and very good work is being 

 done. 



As a general rule two guns to a machine 

 are most often employed and are probably 

 the most economical unit for the average 

 orchardist to employ. In the case of very 

 large trees the time will come in most or- 

 chards when some spraying will have to be 

 done from the top of the rig in order that 

 the upper portions of the trees may be thor- 

 oughly protected. Considering 5 gallons 

 per minute from each gun as an average 

 amount of material to use it can be seen that 

 for ordinary usage the machine should han- 

 dle 10 gallons per minute of material ac- 

 tually used. If more guns can be used eco- 

 nomically in the orchard a proportionate 

 pump capacity is needed. A sprayer should 

 possess together with the normal peak out- 

 put from the guns considerable reserve in 

 the form of overflow. Just what added re- 

 serve is needed is a debated question at the 

 present time, but from field experiences 

 that have come to the attention of the 

 writer it appears that a machine should 

 pump at least 3 gallons more a minute than 

 is actually required in operating the outfit. 

 This gives a little leeway in the case of the 

 engine or pumps not working properly. 

 There are always times — at sometime dur- 

 ing the spraying season — that this added re- 



serve may be called upon to keep the spray 

 operations going. In the case of a machine 

 of little or no reserve above the actual re- 

 quirements there is always a tendency to 

 crowd the engine in order to get the spray 

 needed to do good work. This usually re- 

 sults in a rapid depreciation of the ma- 

 chine and is invariably accompanied with 

 successions of breakdowns. In the writer's 

 opinion then, the machine constructed to 

 pump 1 5 gallons per minute at a pressure 

 of 300 pounds at least should prove to be 

 an outfit of great effectiveness. 



"PJOUlBTLESS we shall see a great im- 

 ■L- ' provement in the many makes of 

 sprayers during the next few years and it 

 undoubtedly will be possible to choose a 



Low pressure from these small capacity 

 outfits does not produce a spray of the 

 proper consistency to accomplish a satis- 

 factory coating. The liquid leaves the guns 

 in a coarse, spattering stream. There is no 

 fineness of division of the particles and the 

 only way that a tree can possibly be covered 

 is to drench it, thereby wasting much ma- 

 terial. Finely divided spray h.as much the 

 same consistency as dust particles where 

 dusting is employed and controls calyx 

 worms and operates in the same manner as 

 in the case of properly applied liquid so- 

 lutions. If this spray is not broken up into 

 a light drifting mist the principle of calyx- 

 worm control is destroyed and poor results 

 are bound to follow. There is no possible 

 chance of obtaining much calyx protection 



Distribution of wormy apples on a tree sprayed with a gun on a poor spray outfit. 

 Low pressure and a coarse, spattering spray was the rule — 17.8 per cent of the 

 fruit above 12 feet became wormy. Do not use a gun on a poor spray outfit — 

 stay with the rods. 



spr.iyer of more or less simple construction 

 to fit the bill. 



We all probably have seen the results ob- 

 tained in orchards sprayed with guns used 

 on small or inferior outfits. Invariably 

 when so employed the gun has not given a 

 good account of itself. A great many re- 

 sults have been tabulated at the Hood 

 River branch of the Oregon Experiment 

 Station and from these tabulations it is quite 

 easy to show where the seat of the trouble 

 originates. In checking up results in vari- 

 ous insect and disease control work the 

 fruits have been segregated at the different 

 heights and their conditions noted. In the 

 case of codling moth control, where spray 

 guns are employed on poor outfits (which 

 developed 175 to 200 pounds pressure) 

 wormy apples developed from a height of 

 12 feet to the tops of the trees to the extent 

 of 17.8 per cent, while but 3.5 per cent 

 became wormy below 12 feet. There is 

 only one explanation for this condition and 

 that is the fact that the spray was not ap- 

 plied in the right form to the tops of the 

 trees. 



in the tops of the trees with a gun throw- 

 ing coarse, spattering spray. This might 

 possibly be accomplished from a tower. 

 Gravity is the factor which allows the poison 

 to reach the calyx end of the uppermost 

 apples. The spray material must be placed 

 there in the proper condition and in suf- 

 ficient amounts to effect a coating as it 

 falls. A coarse spray goes up in large drop- 

 lets and comes down in much the same 

 form and a large portion passes over the 

 tree in the form of an arc. Unless a very 

 excessive amount of spray material is thrown 

 Into the tops of the trees only a few of the 

 calyx ends will receive the spray. Good con- 

 trol can be accomplished when the spray is 

 applied in the proper form. 



GROWERS who are having difficulty 

 with their scab control are up against 

 the same proposition. We know that the 

 apple scab fungus attacks both the upper 

 and under surfaces of the leaves as well as 

 the fruit. Our experimental work has dem- 

 onstrated that it is just as important to cover 

 {Concluded on fage 20) 



