Page 8 



BETTER FRUIT 



April, IQ20 



entrants also Increases. The very 

 marked difference between the figures 

 obtained on the check trees as compared 

 to both dusted and sprayed indicate the 

 influences that are brought to bear in 

 calyx worm control. Experiment 2 

 (dust) gave the best calyx worm con- 

 trol during 1917 where the ratio was 

 found to be 92.99 to 7.01, side and calyx 

 worms respectively. Experiment 4 

 (rods) followed with an 80 to 20 ratio. 

 The gun was not tested in this orchard 

 in 1917. These blocks, as has been 

 stated, were sprayed extra in Septem- 

 ber. The rods in the heavier infesta- 

 tion gave slightly better calyx control, 

 73.55 per cent being side entrants as 

 compared to 71.6 per cent in the dust 

 block. 



Dusting work was not continued in 

 the Arkansas Black orchard in 1918 but 

 was continued in a block of Newtowns 

 in a different orchard. As will be noted 

 in experiment 6 the check block for 

 this series of experiments developed a 

 17.64 per cent infestation. During this 

 season throughout the district a greater 

 percentage of side worms entered than 

 calyx worms. The unsprayed checks 

 developed 7.3.29 per cent side worms as 

 compared to but 26.7 per cent calyx 

 worms. However, regardless of this 

 rather small percentage of calyx worms 

 the difference of amount in calyx 

 worm control is again pointed out in 

 the results obtained. During this season 

 calyx entrants were cut down to 5.2 

 per cent in the dust block. These re- 

 sults were checked against a block 

 sprayed with a gun in the same orchard 

 which developed but .44 per cent 

 wormy fruit, and perfect control as far 

 as caiyx worm control is concerned. 

 This work was continued in these same 

 blocks in 1919, and though not pre- 

 sented on the chart gave the following 

 results. The check trees developed 

 80 per cent side and 20 per cent calyx 

 infestation. The figures in the dust 

 block are 96.77 per cent side worms and 

 3.22 per cent calyx worms. The gun 

 block, however, upheld the 1918 per- 

 formance and developed not a single 

 calyx worm in the apples counted. The 

 figures look too good but nevertheless 

 these are the ones obtained. At this 

 point I might add that this orchard 

 outside of the experimental work that 

 has been conducted with dust, has been 

 sprayed with a gun only since 1917. 



Before being too firmly convinced of 

 the relative merits of calyx worm con- 

 trol with dust and with spray gun a 

 series of experiments were arranged in 

 1919 to compare the merits of the gun 

 and rod in an orchard which had been 

 quite wormy for several years. The 

 orchard which was chosen for this 

 work suffered a loss of 20 to 30 per 

 cent damage in 1918. In 1917 the loss 

 was even greater. In the spring of 

 1919 many worms were found on the 

 trunks of trees so there was no doubt 

 but that there would be plenty of in- 

 sects with which to work. Three blocks 

 were chosen through the center of the 

 orchard. One was sprayed with the 

 gun throughout the season (experiment 

 10). Another was sprayed with twelve 

 foot rods throughout the season (exper- 



iment 11). Experiment 9 gives the re- 

 sults obtained with the use of rods in 

 the calyx application, guns being used 

 for the other sprays. The varieties used 

 in the tests were Jonathans, Newtowns, 

 and Spitzenbergs. The trees were fif- 

 teen years of age. This discussion, pre- 

 sented in the accompanying table, with 

 the exception given, includes the re- 

 sults obtained in the Spitzenberg block 

 only. The spray was applied by the 

 owner and his hired man under the 

 supervision of the writer who followed 

 behind the men while the trees were 

 being sprayed in each application. Two 

 guns were used. 



This experiment, however, included 

 the Newtown variety only. The un- 

 sprayed checks in this v^iety showed a 

 much lower percentage of calyx worms, 

 which naturally influences comparative 

 ratios given in the table on a 3% horse- 

 power outfit of well known make. 

 The work was well done and well timed 

 throughout the season. Five applica- 

 tions of arsenate of lead were used dur- 

 ing the year; the last one, as the season 

 finally turned out, was not very import- 

 ant. A summary of the results not only 

 show that the gun held its own in ob- 

 taining codling moth control but gave 

 better control than the rods and also 

 where the rods were substituted in the 

 calyx application that the calyx cups 

 might be filled. The check trees de- 

 veloped an infestation of 53.6 per cent; 

 the ratio of side to calyx worms was 

 45.16 to 54.83 per cent. In experiments 

 9 and 10 (rods in the calyx and guns 

 in other applications) the percentage 

 of calyx entrants was found to be prac- 

 tically the same, .34 and .35 per cent. 

 The ratio of side to calyx worms being 

 85.74 to 14.28 per cent for the rods and 

 84.24 to 15.71 per cent for the guns. It 

 is interesting to note here that the field 

 control obtained by the owner two 

 rows away from the check trees ran 

 .56 per cent wormy, the fruit being 

 checked up at random at harvest time. 

 This demonstrates what can be done 

 in a badly Infested orchard in a season. 

 Another point upon which there is 

 no experimental information available 

 is the matter of worm control in the 

 tops of large trees with the guns. At 

 picking time the fruit was segregated 

 in the different experiments in lots 

 from the ground to 12 feet and from 12 

 feet to the tops of the trees (experiment 

 12 and 13). The trees in question were 

 quite tall, considerable fruit occurring 

 from 20 to 25 feet from the ground. Up 

 to a height of 20 feet effective control 

 can be obtained, above this point, how- 

 ever, effectiveness rapidly decreases. 

 For example, in one tall tree 123 apples 

 (which are included in the results giv- 

 en in experiment 13) were picked at a 

 heighth of 25 to 28 feet and 22 of them 

 were found to be wormy. The results 

 indicate that calyx worm control in 

 the lower portion of the tree is su- 

 perior to that obtained in the higher 

 portions of the trees, yet the ratio of 

 calyx control does not fall far below 

 that of the average condition. In this 

 experiment apples taken at a heighth of 

 12 feet to the tops of the trees devel- 

 oped 81.13 per cent side worms and 

 18.86 per cent calyx worms. 



From figures which I have been ac- 

 cumulating it appears that the codling 

 moth is inclined to deposit more eggs 

 in the tops of the trees than nearer the 

 ground. It is quite important then that 

 the fruit should either not be grown at 

 that heighth or should be very well 

 sprayed in order to reduce worm infes- 

 tation to the minimum. 



The poor results that have been ob- 

 tained with the spray gun are not due 

 to the principal involved in applying 

 the spray. Unsatisfactory control can 

 be the result of the misuse of one of 

 three — or perhaps better — the combin- 

 ation of three misused factors. These 

 are poor equipment, poor work and 

 irregularity of application. Of the three 

 factors the first mentioned is probably • 

 the most important from the standpoint 

 of the use of the gun. The other two 

 factors are contingent upon the first. 

 The spray gun is a useless accessory on 

 a poor spray outfit. It is little better 

 than nothing and will never give good 

 results. Our up-to-date 3% horse power 

 sprayers are indeed too small to handle 

 two guns effectively, they will handle 

 one in good shape. A machine of this 

 power, in order to throw a spray of the 

 proper quality must maintain a pressure 

 of at least 275 pounds. In the experi- 

 mental work just referred to (orchard 

 No. 4, table X) a machine of this char- 

 acter was used. In order to keep the 

 spray in proper form it was tuned up 

 and punished throughout the season. 

 When you begin to punish a gas engine 

 pump trouble begins, and the owner 

 of this machine had his share. This 

 condition of affairs existed in many or- 

 chards throughout the valley and was 

 typical of no particular make of spray- 

 er. A spray machine, in order to live 

 the life that it should and at the same 

 time deliver the goods must have a 

 liberal reserve. A machine of 10 horse 

 power is none too much. Such spray 

 machines are now coming into use and 

 it will be only a question of a very few 

 years until all of the present so-called 

 modern sprayers will go into, the dis- 

 card. The results given in orchard No. 

 1, table VIII, were obtained with one 

 of these larger types of sprayers. 



The gun where operated with small 

 inferior equipment has given a very 

 poor account of itself. I have care- 

 fully checked up the results obtained in 

 several orchards where poor equipment 

 has been used. The growers tried to 

 do good work and timed their applica- 

 tion well. Breakdowns and low press- 

 ure, which is usually the rule when a 

 machine is not working right has led 

 to very poor results. The lower fruits 

 as a rule came through the season in 

 fairly good shape. In 1918 in one of 

 these orchards under observation the 

 following records were made. Apples 

 growing below 12 feet developed a 

 worm infestation of 3.55 per cent. 

 Apples growing between 12 feet and 

 the tops of the trees developed an in- 

 festation of 17.63 per cent. There is 

 only one explanation for this condition 

 and that is the fact that the spray was 

 not applied properly to the tops of the 

 trees. 



Continued on page 38. 



