120 



the whole of a cluster may be destroyed 

 from infection arising in one of them. 

 Some of the diseased apples fall to the 

 ground and rot away, but others remain on 

 the tree and gradually become shrunken 

 and wrinkled; in this " mummified " con- 

 dition they remain until the following 

 summer, when the fungus redevelops and 

 infects the new crop. 



On certain varieties, e.g., James Grieve 

 and Lord Derby, the disease extends from 

 the affected apples to the fruiting spur, 

 and may even cause cankers on the 

 branches. 



The rot may continue after the fruit is 

 picked; hence the necessity of careful sort- 

 ing at the time of storing and packing, for 

 all apples showing a trace of rot should be 



Fig. 4. — An Apple with Brown Rot- 

 Fructigena." 



' Monilia 



rejected. In the case of apples affected 

 when stored, the discolouration, at first 

 brown, becomes darker until often it is 

 quite black. 



The same fungus also occurrs on pears, 

 plums, cherries, damsons and peaches, 

 causing, as in the apple, a brown rot of 

 the fruit. 



Monilia cinerea is more dangerous than 

 Monilia fructigena, for it not only pro- 

 duces a brown rot of fruit, but in plums 

 and cherries causes, in certain seasons, a 

 serious Blossom Wilt, the flowers becoming 



withered and blackened as though killed 

 by frost; it also kills the twigs and may 

 invade the branches, thus causing gumming 

 and cankers. On plum trees a condition 

 which has been called the " Wither Tip " 

 disease is of frequent occurrence. In this 

 case tlie fungus attacks the young shoots 

 of the current year through the newly un- 

 folded leaves, with the result that the 

 terminal portion of the shoot wilts and 

 becomes dry and withered. Theie 

 withered shoots may be recognised jn 

 winter by the fact that they usually retain 

 some of their withered leaves, and if such 

 shoots are examined in spring, the fungu^; 

 will be seen as grey pustules bursting 

 through the bark; the spores which 

 develop on these pustules serve to infect 

 the flowers and young shoots as they un- 

 fold. 



A form of Monilia cinerea is responsible 

 for a serious " Blossom Wilt and Canker 

 Disease " of apple trees. Infection takes 

 place through the flowers which are killed 

 in the course of a few days, then as the 

 fungus invades the spurs, the leaves round 

 the base of the flowers begin to wilt; this 

 withering of the leaves on the flowering 

 spurs is the first obvious symptom of the 

 disease, and is seen about a fortnight after 

 the trees come into blossom. When the 

 spurs are short the disease soon extends 

 into the branches, and cankers are pro- 

 duced, often resulting in the girdling and 

 subsequent death of large branches. 



The fungus lives through the winter in the 

 dead spurs, and in the cankers, and by the 

 following spring develops a number of small 

 grey, cushion-like tufts (see Fig. 5), on 

 which are produced the spores which infect 

 the flowers as they open. The disease 

 occurs on many varieties of apples, but 

 some are more susceptible to it than 

 others, e.g., Lord Derby, James Grieve, 

 Ecklinville and Cox's Orange Pippin. 

 The most effective way of controlling this 

 disease is to cut out all dead spurs during 

 the summer when they are readily recog- 

 nised by reason of their dead leaves, but 

 care must be taken to remove all dead and 

 discoloured wood and bark, and if cankers 

 have been produced, these, too, must be 

 cut out; if the operation is delayed until 

 winter, the dead spurs are not so easily 

 distinguished. 

 Spraying is not to be relied upon to keep 



