THE PEACH BUD MITE. 



113 



REMEDIAL CONSIDERATIONS. 



There is but little information available bearing on the control of the 

 peach bud mite. Prof. Waite, in conversation, informed the writer 

 that when the trouble was present several years ago in his nurseries, 

 he was able to prevent injury by thoroughly spraying, during the 

 dormant season, the trees subject to injury with lime-sulphur wash. 

 It was not learned, however, whether trees were left untreated for 

 purposes of comparison. The known effectiveness of sulphur, dry 

 or in soluble compounds, against mites in general is ground for the 

 belief that sulphur sprays would be effective in this case. It is 

 uncertain, however, whether the mites winter exclusively on the 

 peach nursery stock. The value of dormant treatments would 

 depend upon the extent to which the mites hibernate on the trees. 

 There is some evidence that they hibernate elsewhere. In the instance 

 of serious injury in the Delaware nursery, earlier mentioned, all of the 

 block of peach stock, save one row, was sprayed with lime-sulphur 

 wash during the spring of 1906 (dormant buds). Examinations by 

 the writer during the following summer did not show any difference 

 between the sprayed and unsprayed trees, and the infestation was 

 uniformly quite prevalent. 



It has been the practice for some years of one large nursery firm to 

 spray blocks of their peach trees during the dormant period with a 

 miscible oil used at full winter strength. Notwithstanding this 

 practice the trees have been seriously injured by the mite, and in one 

 large block thus sprayed during the dormant period of the spring 

 of 1910 the mite was especially prevalent in one portion during the 

 summer of 1911. These results suggest that the mites also winter 

 in other places than on the peach trees. 



In the experience of Mr. Phillips, already quoted, (p. 106), con- 

 siderable benefit resulted from prompt attention to pruning the injured 

 plants, so as to correct the trouble as much as possible, by the selec- 

 tion and forcing of one of the best lateral shoots. He treats this 

 question at some length (loc. cit.) and his table of results from prun- 

 ing tests is herewith quoted: 



Data in regard to pruning peach trees in the nursery affected by "stop-back" 



Varieties. 



V.'onderful . 

 Champion. 



do 



(?) 



Total 

 number 

 of trees 

 in row. 



1,259 



1,010 



1,130 



1G0 



Number 

 injured 



by 

 May 18. 



147 

 150 

 133 

 2 25 



Number 

 pruned 



May 18. 



147 



150 



Check. 



2 25 



Number 

 of crooked 



trees 

 Aug. 15. 



46 



40 



iU9 



3 



Number of 

 injured 



trees that 

 grew lip 

 straight. 



101 

 110 



22 



Percentage 



of pruned 



trees that 



grew up 



straight. 



68 

 73 



88 



1 Some time after this row was decided upon as a check, it was learned that one of the laborers had pinched 

 a number of trees at one end. This accounts for there being fewer crooked trees than had been injured 

 Mavl8. ' 



2 June 22. 



