1907.] American Gooseberry Mildew. 



455 



the bushes thoroughly with potassium sulphide in the pro- 

 portion of one ounce to two gallons of water, the treatment 

 to be repeated at intervals of a fortnight ; and for subsequent 

 sprayings a stronger solution of two ounces of potassium 

 sulphide dissolved in three gallons of water. 



As it was thought that there might be a danger in com- 

 mencing with one ounce to two gallons of water, — the ex- 

 perience of some foreign countries showing that this strength 

 caused the leaves and berries to fall off — spraying was com- 

 menced on 26th March with potassium sulphide at the rate of 

 one ounce to three gallons of water. Three plantations at Pinvin 

 (Pershore) and ten at Lenchwyck (Evesham) were dealt with. 



As no scorching of the foliage or other ill effect was apparent 

 from the use of the wash at this strength in the case of the 

 first plantation, the strength was increased to one ounce to 

 two gallons of water, and this solution was used for the 

 first spraying at the other twelve plantations. 



At the second spraying a further increase was made in 

 the strength of the wash, one ounce of potassium sulphide 

 being used to one and three-quarter gallons of water. From 

 the use of the wash at this strength no scorching of the foliage 

 or injury to the blossom, which was fully out, was noticeable, 

 and the strength was again increased on 22nd April to one ounce 

 to one and a half gallons of water. Still no injury of any 

 sort to the bushes was apparent, and a stronger solution of one 

 ounce to one and a quarter gallons of water was tried. 



At the fourth spraying of the affected bushes, which was 

 commenced on 15th May, it was decided to try one ounce of 

 potassium sulphide to one gallon of water. At the end of 

 May it was thought advisable to substitute sodium sulphide 

 in the place of the potassium sulphide (liver of sulphur) which 

 had been used hitherto, partly owing to the former being 

 manufactured commercially and in consequence being con- 

 siderably lower in price than the latter. The potassium 

 sulphide was obtained at yd. per lb., in 20 lb. lots. It could 

 most probably have been obtained at a cheaper rate in larger 

 quantities, but it was thought more satisfactory to procure.it 

 in small lots, so as to ensure it being quite fresh. The price 

 of the sodium sulphide was £6 per ton, which works out at 

 less than id. per lb. The spraying with the sodium sulphide 



