50 



remain dormant during the whole winter. In spring the spores 

 are liberated and shot out into the air. They are blown by 

 the wind on to the new leaves just unfolding and infection 

 results. The delicate white mould soon appears and a crop 

 of summer spores follows in a few days. From these 

 primary Y infections, new or " secondary " infections take 

 place and thus in favourable weather the mildew spreads 

 rapidly. 



European Gooseberry Mildew may occur as early as May 

 and lasts throughout the season. It is widely distributed 

 and as a rule causes but little damage; it is mostly found 

 under heavy shade and on old bushes. When the attack 

 is severe the leaves die, and fall off early in the season; the 

 fruit as a result is checked in its growth and remains small. 

 If a severe attack follows for several seasons in succession 

 the bushes become stunted and may even be killed. Red 

 currants are also occasionally attacked by European Goose- 

 berry Mildew. 



The most obvious differences between the present disease 

 and the American Gooseberry Mildew may be summed up 

 as follows. Whereas in the European Gooseberry Mildew the 

 fungus occurs as a very delicate mould or mildew on the 

 leaves, the American Mildew forms a dense white woolly 

 mould which, though found on the leaves, attacks chiefly the 

 shoots and berries. As the growth of the American Mildew 

 continues the white stage gives place to a light brown woolly 

 phase and finally to a thin dark-brown felted mat, which is 

 very conspicuous on the berries and shoots. This condition 

 is never found in European Gooseberry Mildew, where the 

 mildew always remains thin and scanty. The resting-spore- 

 fruits, moreover, are in the European Mildew found exposed 

 on ihe. leaves, whereas in the American Mildew they are 

 embedded in the felt on the shoots and berries. Occasionally 

 the two mildews are found on the same plant. 



Measures of Control. European Gooseberry Mildew can 



be controlled by spraying. If the amount present is small it- 

 will hardly be necessary to resort to this treatment, but if the 

 attack. is severe, or if from previous experience a bad outbreak 

 of mildew may be expected, it will be advisable to spray 

 occasionally with lime sulphur. The first application should be 

 given early in May and at the rate of 1 part lime sulphur to 

 60 parts water. 



The ground under diseased bushes should be dug over in 

 winter in order to bury the winter spores, and if onlv a few 

 bushes are grown the additional precaution may be taken- 

 of collecting and burning in autumn the dead and fallen 

 diseased leaves. 



