Commercial Gardening 



same fungus, which often follows Red Spider or green fly. The leaves 

 that are attacked often bleach, and have a silvery look round the edge. 

 The berries show a brownish stain, which finally becomes soft and 

 covered with the mould. 



Prunings should not be left under the bushes, neither should they 

 be left in heaps here and there to rot. All such accumulations form 

 centres of disease, from which the fungus spores are diffused in myriads 

 by wind, birds, &c. 



Where the disease has previously existed, the bushes, and also the 

 ground, should be thoroughly drenched with a solution of sulphate of 

 copper during the winter months, before the leaf buds expand. This 

 should be followed by a spraying with half-strength Bordeaux mixture 

 just when the fruit is set. 



Gooseberry- and Currant-leaf Spot (Pseudopeziza ribis=Glososporium 

 ribis). This disease is very prevalent on the leaves of both Gooseberries 

 and Currants, but is generally neglected, as its significance is mostly un- 

 known to growers, or it is mistaken for the work of " green fly ". Leaves 

 that are attacked and as a rule every leaf on a bush is attacked when 

 the fungus once gains a foothold fall early in the season during a severe 

 attack. This not only checks the full development of the fruit already 

 present, but also unfavourably affects the crop of the following season, on 

 account of the imperfectly matured wood. This disease is confined to the 

 leaves, and its presence is indicated by the appearance of numerous very 

 small warts, most abundant on the upper surface of the leaf, which com- 

 mences to turn yellow soon after being attacked. If allowed to run its 

 course the fungus spreads rapidly, the spores from the leaves first diseased 

 being spread by wind, rain, insects, &c., to adjoining healthy leaves. If 

 the bushes are sprayed with half-strength Bordeaux mixture, or with 

 potassium sulphide, when the disease first appears, its spread will be 

 arrested. This is certainly worth doing, as the disease saps the vigour 

 of the bushes to a serious extent. 



It is important to remember that when the leaves have fallen the 

 bush is perfectly free from disease, and will remain so unless infected 

 afresh. Such infection proceeds from the old fallen leaves the following 

 spring; hence if the leaves are dug in during the winter, or got rid of 

 in some way, the disease will not reappear. 



Black Knot (Plowrightia ribesice). This disease is met with most 

 frequently on Gooseberry bushes, although it sometimes occurs also on 

 Black- and Red-currant bushes. The first indication that something is 

 going wrong is the wilting or yellowing of the leaves, which commence 

 to fall early in the season. This condition of things may continue for 

 two or three years before the bush dies. Sometimes only a single 

 branch shows these symptoms, when a careful examination of the lowest 

 portion of the branch will reveal the presence of numerous short, trans- 

 verse, gaping cracks, 1 to 2 lines in length, each crack being filled with 

 a jet-black substance, which is the fruit of the fungus. If only a single 



