Mail, 1922 



BETTER FRUIT 



Page Seven 



Factors Inducing Calyx Spray Injury 



Query by Affected Grozver: Answer by Plant Expert 



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I Here is detailed an unfortunate | 



I loss on afple crop of 1921, as re- | 



I forted by O. G. Rogers, of Looking | 



I Glass, Oregon. Mr. Rogers, from | 



I Ais study of the damage and curtail- | 



I ment of crof deduced that the cause I 



I was largely that of injury by the | 



I calyx sfray of lime-sulfur and arsen- \ 



I ate of lead. He built uf strong evi- I 



I dence of this. Ez'ery affle grozver i 



I finds the froblem presented one of | 



I interest. Diagnosis of the case im- I 



I mediatel y follozcs Mr. Rogers's | 



I article. I 



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AT THE beginning of 1921, the fruit 

 -^-*- growers of our section, particularly the 

 apple growers, had great hopes of a good 

 fruit year. It was due. 



There were plenty of large plump fruit 

 spurs and the trees were in healthy vigorous 

 condition. Except for the danger of frost 

 all that was necessary to realize our hopes 

 was successfully to combat the insects and 

 fungus diseases. 



The above condition particularly applies 

 to us and our orchard of Winter Banana, 

 Spitzenberg and Newtown apples. The 

 trees are ten-year-old and everything w.is as 

 hoped for until after the calyx spray was 

 applied. In this spr.iy was used the same 

 strength of lime, sulfur and arsenate of 

 lead as in former years: that is, 1 to 40 

 pounds lime and sulfur, plus 3 to 200 ar- 

 senate of lead. 



.Although we had never had scab in other 

 years but, because of so much being at 

 stake, I made particular effort to wet the 

 leaves as well as the calyx end of apple. 

 About one week after applying this spray 

 I noticed the leaves from some of the last 

 trees sprayed were falling. 



I supposed then that the last tank spr.ayed 

 out was made too strong of lime and sulfur, 

 but a few d.iys later the falling of the 

 leaves was fairly general throughout the 

 orchard. This defoliating of the trees 

 kept up until after the 30-day spray. 



^ My neighbors and the experts who 

 visited the orchard were not willing to con- 

 cede that damage was due to spray, but 

 thought it caused by winter injury. How- 

 ever, I was convinced that spray was largely 

 at fault because some few trees that were 

 skipped showed no such condition. 



Coincident with all this, the semi-naked- 

 ness of the trees, causing a devitalized con- 

 dition, seemed to throw the doors open to 

 the scab, for scab was invariably worse 

 where the foliage had fallen the most. On 

 such trees the scab ran as high as 90 per 

 centimeter, and from that down to 50 per 

 centimeter, while on the trees that were 

 skipped scarcely any was apparent. 



The temperature at the time of spraying 

 was about 70 to 75 degrees, unusually warm 

 for so early in April. No doubt this 

 caused the lime and sulfur to burn the 

 leaves. Winter injury might, in a limited 

 way, have been a factor. 



However, there was no need of crying 

 over spilt milk. The dam.ige was done, 

 the question was how to salvage the most 

 from the wreck. Thinning and good cul- 

 tivation were the only things left to do. 

 So we thinned, thinned again and, in part, 

 the third time, always taking the apple that 

 showed enough scab to make it a cull or 

 even "C" grade so that, in many cases, a 

 limb which could easily carry a dozen 

 apples had only two or three. In the 

 orchard as a whole there was prob.ibly 60 

 per cent of what would have been left 

 under normal conditions. 



The result was we had less apples thrown 

 into culls because of scab than for sun 

 scald or other defects and they were larger 

 than apples of the same variety grown in 

 this communit\-. 



My conclusion from this experience is 

 that the college should furnish us a table 

 of temperatures to guide us in applying 

 these sprays that are liable to burn the 

 foli,ige. 



I learn now that many growers use 1 

 to 5 solution of lime and sulfur for the 

 calyx spray and 1 to 60 in the 30-day spray. 

 I learn also that others nearby who used 

 the same strength as I did and sprayed on 

 the same day had practically the same 

 results. 



It is possible the type of nozzle used 

 and the power of the machine make a dif- 

 ference and that one could regulate the 

 strength of the solution according to the 

 kind of work the spray outfit is capable of 

 doing. At any rate, we never had any such 

 trouble when using our old machine, which 

 was not capable of doing thorough work. 



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I The deduction of Mr. Rogers on I 



I the question of injury by the calyx I 



I sfray was submitted for expert analy- \ 



I sis, to Professor H. P. Barss, path- % 



I ologist of Oregon Agricultural Col- \ 



I lege Experiment Station. What fol- | 



I lows is his statement on the subject. I 



I His analysis has z'ery practical appli- \ 



I cation, for it not only shows how I 



I such spray injury may come about, \ 



I but proceeds then to suggest the un- | 



I derlying causes which may be eli- \ 



I 7ninated, at least in most instances. 1 



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/RESERVATIONS made by the Oregon 

 ^-^ Experiment Station last year showed 

 serious spray injury to apple trees in many 

 Western Oregon orchards such as reported 



by Mr. Rogers of Looking Glass. The in- 

 jury took the form of leaf burn and leaf 

 drop and was frequently followed by severe 

 dropping of fruit. In some instances this 

 injury took place after the "pink" or 

 pre-blossom spray, but for the most part, 

 the principal damage resulted after the 

 calyx spr.ay had been applied. 



Many growers believed that possibly the 

 lime sulfur was used too strong, but in view 

 of the fact that ordinary dilutions were 

 used in practically all these cases, dilutions 

 that in other years have given very little 

 if any injury, we must look to other causes 

 than strength of spray to explain the situa- 

 tion. 



In the first place attention must be 

 called to the fact that apple trees vary a 

 great deal in the matter of susceptibility 

 to spray injury with lime sulfur, depend- 

 ing upon the condition of vigor and upon 

 the weather conditions which prevail. Ob- 

 servations show that orchards planted in 

 fertile soil or in soil where the fertility has 

 been maintained by the efforts of the 

 grower and where proper cultivation has 

 resulted in healthy root conditions from 

 season to season have proved not as subject 

 to serious spray injury as orchards in poor 

 soil, or in soil which has not been cultivated 

 enough to conserve sufficient moisture 

 through the season. The reason lies in the 

 effects on the vigor of the trees. 



Where trees are grown on land that is 

 likely to be water-logged in early spring, 

 or on soil that dries out before the end of 

 the growing season the health of the root 

 system is impaired and the leaves on such 

 trees are more than ordinarily subject to 

 spray injury. Vigor of root system and 

 consequent vigor of foliage is greatly pro- 

 moted by the very early start in spring cul- 

 tivation practiced by an increasing number 

 of growers each year. 



Experiment station tests disclose the 

 fact that plowing before the trees come out 

 in the spring tends to bring about a healthy 

 root condition because of the good soil 

 aeration permitted by this practice at the 

 very outset of the season. Furthermore, 

 early plowing is of great advantage in scab 

 control since the old leaves which carry 

 scab through the winter and pass it on to 

 the new growth in the spring are, to a con- 

 siderable extent, covered up so they can no 

 longer discharge their disease-producing 

 spores in the orchard. 



The relation of proper cultivation and 

 care to spray injury was well illustrated in 

 an apple planting last season where the trees 

 were all of the same age and variety, but 

 where one part of the planting had been 

 poorly cultivatd the previous year and had 

 not been given the proper early spring cul- 



{Continued on page 24) 



