374 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



only very few were found in 1912, owing, doubtless, to the pupae 

 having been left behind with the old soil. This point is of some im- 

 portance, for the perithecia of the fungus (if there were any remaining 

 over from 1910 crop) would probably have been left behind too. 

 The bushes were pruned and it seemed evident that in January 1912 

 they were free from the fungus. 



About the time the fruits were swelling in May 1912, however, 

 the mildew again appeared, mostly at one end of the plantation 

 (not on varieties that had been attacked in 1910), but quickly spread 

 all through, attacking not only the young growths but seriously 

 damaging the fruits as well. Whence did the attack come ? No new 

 gooseberries or currants had been introduced to bring it afresh, and 

 yet it was to all appearance a fresh attack. Had insects or wind brought 

 the spores, or had someone coming from an affected plantation brought 

 them on his clothes and left them behind in walking through the bushes ? 



The bushes were again thoroughly tipped in October as soon as 

 growth had ceased, and, it was hoped, before the perithecia had fallen. 

 But this measure was quite in vain, for in 1913 the attack was at least 

 equally bad, commencing at the end of May, spreading rapidly through 

 the plantation, and attacking the berries as in 1912. Probably, if the 

 berries were not attacked, the disease would be regarded as not more 

 serious than the ordinary rose mildew, but the attack on the fruit 

 causes the loss of a great part of the crop, the berries being checked 

 in growth, badly disfigured, and not able to be marketed. [It is now, 

 rightly, illegal to send mildewed fruit to market, and several cases 

 of transgression have recently met with fines.] 



No spraying measures were adopted until 1913, but it was thought 

 well to spray in early May with potassium sulphide (liver of sulphur) 

 as a preventive measure, which was, as we have seen, unavailing. The 

 spraying was done before the mildew made its appearance, with a 

 solution of 1 oz. to 3 gallons of water. [If complete protection by cover- 

 ing the foliage with a fungicide were aimed at, it would have been 

 necessary to spray every other day or so, since the bushes were in a state 

 of rapid growth. This was of course impossible, and the most that could 

 be hoped for was the protection of the least susceptible parts and 

 the destruction of any spores that happened to be germinating. This 

 spraying had no bad effect on the foliage. It was carried out during 

 dull weather, as were the sprayings to be referred to immediately.] 



After the outbreak appeared a further spraying with sulphide of 

 potassium (1 oz. to 3 gallons of water) was carried out. This had a 

 remarkable effect upon the bushes, some of them being almost 

 completely defoliated within 24 to 36 hours, others suffering not at all. 



Table I. shows the extent of the damage and the manner in which 

 the different varieties responded to the spraying. 



It should be explained that there are usually two bushes of each 

 variety in the plantation, though occasionally there are three and 

 sometimes only one. The number following the name in the table 

 shows the number of bushes behaving in the manner indicated at the 

 head of the column. 



