ERADICATION OF BLACK-CURRANT GALL-MITE. 121 



experiments, and. secondly, the Large quantity of soap used. But 

 once having proved that the mite could be destroyed by the us 

 sulphur, it remained to be demonstrated in what form it was best 



applied and whether or not it could he shown that any benefit resulted 

 from a smaller number of applications. 



With these two objects in view a series of experiment- was com- 

 menced early in 1905 on a piece of land set apart and prepared for 

 the purpose by the council of the University of Birmingham. 



On this plat -even rows of bushes were planted, consisting of Black 

 Naples, Baldwins, and Boskoop Giant. All were a- badly affected 

 with "big bud " as any that could be obtained; indeed. T have never 

 seen worse. The plat of land was far from an ideal one and the last 

 that a fruit grower would have chosen, so that the bushes had no 

 natural advantages in their favor. 



The experiments carried out were as follows: Row- 1. 2, and 3 were 

 dusted with equal parts of unslaked lime and flowers of sulphur. 

 Bow- -k 5, and 6 were -prayed with a mixture consisting of 1 pound 

 of lime. 1 pound of sulphur, and 20 gallons of water, while row 7 

 was sprayed with a mixture consisting of 1 pound of sulphur, 1 

 pound of soft -oap. and '20 gallon- of water. 



Summary. — It is very evident that all the bushes benefited by the 

 application of lime and sulphur. It would have been better, how- 

 ever, had a little less lime been used (1 part of lime to 2 part- of 

 sulphur has acted as well). In the case of those bushes that received 

 a single dusting, the big buds were considerably reduced in number, 

 not more than one-fourth of the number being present in October 

 as there were in February. Where two dustings were given, a dis- 

 tinctly marked diminution over tie living one dusting was 



shown, while where three dustings were applied the mite was almost 

 exterminated. It must be borne in mind that neither a -pray fluid 

 nor dry application will reach the eggs in the bud-, and it seems clear 

 that the number of adult mite- which successfully migrated from 

 the old buds into the new ones was very -mall indeed. In all cases, 

 the mite- found were immature specimens. 



Spraying with lime and sulphur. — The results obtained by -praying- 

 were not so good as those by dusting. A large number of buds were 

 affected, and in many of them there were adult and immature mites 

 and eggs. The differences between the one. two. and three applica- 

 tions of the spray fluid were quite in keeping with those found to 

 obtain where dusting had been done. The fewer the applications 

 the more bud- affected and the greater the number of mitt 4 -. 



Spraying "-if// soft soap "n<l sulphur.— How 7 was -prayed twice 

 with the spray fluid above mentioned. When the bushes were ex- 

 amined in October a fairly large number of big bud- wa- noticed: 



