1907.] American Gooseberry Mildew. 



547 



the leaves remain on the bushes, the best spray is made by 

 dissolving liver of sulphur (known to pharmaceutical chemists 

 as Potassa sulphur ata) in water. For the first spraying 1 lb. of 

 liver of sulphur may be used in 48 gallons of water, but there- 

 after not less than 1 lb. in 32 gallons should be employed. 

 Spraying should be repeated at intervals of from 7 to 20 days 

 according to the state of the weather and the danger of infection 

 apprehended. Spraying should be done on a dry day in order 

 that the spray may have time to dry upon the bushes. If it is 

 necessary to spray in wet weather stronger spray fluids should be 

 employed. If heavy rain should fall immediately after spraying 

 the work should be repeated as soon as possible. 



Treatment of Suspected and Infected Bushes. — Should any sus- 

 picious symptoms be discovered on the plants in spite of the pre- 

 cautions already mentioned, the case should at once be reported 

 to the Board, or, where an Order of the Board applies, to the 

 local authority. A few slips of bushes showing the disease 

 in its most marked form should be cut off and sent carefully 

 packed in a strong wooden or metal box (not a cardboard box) 

 with the report to the Board or to the local authority as the 

 case may be. The postage on letters and packages sent to the 

 Board by letter post need not be prepaid. 



The following instructions are for the guidance of growers, 

 who must remember that during the summer and autumn 

 months the spores which spread the infection are readily 

 carried from plant to plant. 



1. Bushes Suspected. — Wherever there is reason to suspect 

 the disease, growers, after reporting as explained above, should 

 immediately destroy as much of the mildew which may exist as 

 possible, by spraying thoroughly all suspected plants or groups 

 of plants, and all plants in their immediate neighbourhood (to 



More water should then be added, gradually working it down to a stiff cream, finally 

 reducing it to a thin cream (" milk of lime "), which will mix directly with the bulk 

 of the water. If this process is faithfully carried out, when the mixture is made up a 

 flocculent, starch-like precipitate is formed, and this precipitate will stick. A 

 granular precipitate is valueless. The "milk of lime " should be poured through a 

 fine sieve or a piece of close sacking to remove grit. The copper sulphate solution 

 and " the milk of lime" being separately prepared, the contents of the two vessels 

 should then be poured together into a tub and the whole made up to 100 gallons. If 

 the mixture is correctly made and safe to use, the blade of a knife held in the mixture 

 for a minute should remain unchanged ; if the blade becomes coated with copper 

 more " milk of lime " should be added until copper is no longer deposited. 



2 M 2 



