1907-] 



American Gooseberry Mildew. 



549 



(c) If the disease is discovered during the winter months, 

 the entire bushes or all the wood formed during the current or 

 preceding year must be at once removed and destroyed. As 

 the spores of the fungus are not distributed in winter a 

 preliminary spraying is unnecessary. 



3 After-Treatment of a Plantation in which Disease has 

 occurred. — The healthy bushes in the plantation should be 

 sprayed with a solution of i lb. of liver of sulphur to 32 gallons 

 of water as soon as the diseased bushes have been disposed of. 

 The spraying should be repeated within a week and be con- 

 tinued at intervals of ten days throughout the rest of the 

 season. 



In the late autumn, as soon as growth has stopped and the 

 leaves have begun to fall, all the bushes in an infected planta- 

 tion should be pruned. Disease occurs almost entirely on the 

 young wood, and if the current year's wood be removed and 

 destroyed by burning or by steeping in a solution of copper 

 sulphate, the danger of disease re-appearing in the following 

 summer will be greatly diminished. The sooner pruning 

 is done after active growth has ceased the better ; so long as 

 the young shoots remain on the bushes there is always the danger 

 that undiscovered fragments of the fungus dropping on the soil 

 will infect it . Suckers should be carefully removed while pruning. 



Early in the new year, and at the latest some weeks before 

 the buds begin to swell, the soil of the plantation should be 

 dug over, and the surface soil buried as deeply as possible. 

 During the winter months the fungus exists in a dormant 

 state, but as soon as spring comes new spores are produced 

 which infect the buds of gooseberry bushes. Burying the 

 surface soil would considerably lessen the chances of fresh 

 infection. 



American gooseberry mildew has also attacked red currants, 

 and there is reason to believe that it may attack black currants 

 and raspberries ; these plants should therefore be kept under 

 observation by fruit growers. 



Should it be necessary to destroy a gooseberry plantation 

 because of mildew, it would be highly undesirable to re-plant 

 the land with gooseberries or currants until a considerable time 

 had elapsed. It is not certain how long the infection may 

 remain in the soil, but growers should let two years at least 



