592 



The Black Currant Gall-Mite. [Jan., 



growers have given the sprayfluid a trial with very satisfactory 

 results. 



The two main objections to the soap and sulphur sprayfluid 

 were, firstly, the large number of applications which were given 

 in my experiments, and, secondly, the large quantity of soap 

 used. But once having proved that the mite could be destroyed 

 by the use of sulphur, it remained to be demonstrated in what 

 form it was best applied, and whether or not it could be shown 

 that any benefit resulted from a smaller number of applica- 

 tions^ 



With these two objects in view, a series of experiments were 

 commenced early in 1905 on a piece of land set apart and pre- 

 pared for the purpose by the Council of the University of Bir- 

 mingham. 



On this plot seven rows of bushes were planted, consisting of 

 Black Naples, Baldwins, and Boskoop Giant. All were as 

 badly infected with " big-bud " as it was possible to obtain ; 

 indeed, I have never seen worse. The plot 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 favour. 



The experiments were carried out as follows : — Rows i, 2, 

 and 3 were dusted with equal parts of unslaked lime and flowers 

 of sulphur. Rows 4, 5, and 6 were sprayed with a mixture 

 consisting of i lb. lime, i lb. sulphur, and 20 gallons of water ;. 

 whilst row 7 was sprayed with a mixture consisting of i lb. sul- 

 phur, I lb. of soft soap, and 20 gallons of water. 



{a) Dusting zvith Lime and Sulphur. — As it was desirable to 

 find, if possible, the minimum number of applications that would 

 give successful results, row i was dusted three times, row 

 2 twice, and row 3 once. The dustings were applied when the 

 bushes were wet on March 31st, April 14th, and IMay 5th. A 

 small pair of bellows were used for the purpose, but better 

 results have since been obtained by the use of the " Coronette " 

 Knapsack Sprayer. 



At the end of June all the bushes were in full leaf, and 

 excepting here and there, where the growing points had been 

 slightly burnt by the lime, they all looked remarkably healthy. 



The remains of the old diseased buds were microscopically 



