53 



THE DIE-BACK DISEASE OF GOOSEBERRIES 



(Botrytis cinerea.) 



The Die-back of Gooseberries is a disease very widespread 

 in England and one liable to occur wherever these bushes 

 are grown, whether in large plantations or in small gardens. 

 Although gooseberries may die-back from various causes, in 

 the majority of cases the serious attacks which occur are' 

 iound to be due to the minute fungus Botrytis cinerea. This 

 fungus is exceedingly common as a saprophyte on decaying 

 vegetation, but, under certain conditions, it becomes parasitic 

 and attacks living plants. The present leaflet is confined 

 10 the disease caused by Botrytis. 



Description of the Disease. The gooseberry bush may be 

 attacked by Botrytis in four distinct places, viz., (a) the main 

 stem and base of the branches, (b) the young wood of the 

 current year, (c) the leaves, or (d) the berries. 



(a) The Main Stem. As regards the main stem, the 

 mycelium (spawn) of the fungus penetrates the outer tissues, 

 and at the end of the season causes the bark to crack and 

 peel off, often in large pieces. The part of the stem first 

 attacked is usually that portion situated at the ground level or 

 a little above it; the fungus kills the wood and eventually 

 " rings " the stem at this place and the whole bush is killed. 

 Before this occurs, however and, in the case of a well-grown 

 bush, death does not as a rule result for several seasons the 

 mycelium of the fungus spreads upward in the stem to the 

 base of the branches. Here it frequently attacks some of the 

 branches so severely that they die. The presence of dead 

 branches in a few bushes, or the death of half the bush, 

 is a characteristic sign of the first appearance of the Botrytis 

 disease in a plantation. 



.Renewed growth of the mycelium of the fungus in the stem 

 takes place every spring, and it is then that the manner 

 in which the fungus exists and spreads can be most 

 easily seen. If a diseased stem be examined during a warm 

 and damp spell of weather in the spring, the appearance 

 shown in Pig. 1 will be observed. The bark will be found 

 to be peeling or cracking off, while greyish, fluffy patches 1 o f 

 a " mould " have appeared at the edges of the peeling bark 

 or in the fissures where the bark is cracked. If there is a> 

 dead branch on the bush, as a rule, small greyish tufts or 

 little cushions which soon develop in suitable weather into 

 fluffy patches such as are shown in Fig. 2 will be found 



This leaflet is based on work carried out by Mr. E. S. Salmon, of 

 Wye, and the illustrations are leproduced from the Journal of the 

 South Eastern Agricultural College, Wye, Kent, No. 18, (1909),' by kind 

 permission of the College authorities. 



