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On the Wood. For many years the mariner in which the 

 scab fungus lived through the winter was unknown. The 

 matter has, however, been carefully investigated at Wye 

 College and it has been clearly established that the fungus 

 passes the winter in a dormant condition on the young wood 

 of many varieties of apples and pears. These diseased shoots 

 provide for the initial infections the following season. Affected 

 wood is readily distinguished by its blistered appearance 

 (Fig. 4) due to the formation of numerous small cushion- 

 like growths of mycelium, just beneath the bark. These 

 cushions remain dormant during the winter. As soon as 

 the spring arrives they recommence growth and finally 

 liberate thousands of spores which infect the young leaves 

 and thus start afresh the life-cycle of the fungus. The in- 

 fected wood varies considerably in appearance with the variety 

 of apple or pear, the blisters being large or small, scattered 

 as in Cox's Orange Pippin (Fig. 4), or crowded together, as 

 is often the case with Lord Sumeld. So far as is possible 

 this scab-infected wood should be cut out when pruning 

 the trees in winter. 



The fungus is probably capable of existing in the wood of 

 most varieties of apples and pears, but it is known to occur 

 plentifully on the following : 



Apples. Cox's Orange Pippin, Cox's Pomona, Ecklinville 

 Seedling, James Grieve, Lord Sumeld, Warner's King, Welling- 

 ton, White Transparent, Worcester Peannain, Yellow Ingestre. 



Pears. Beurr6 Bose, Beurr6 Diel, Clapp's Favourite, 

 Doyenn6 Boussoch, Doyenn6 du Cornice, Jargonelle, Le 

 Lectier, Marie Louise, Pitmaston Duchess, St. Germain. 



The young wood of Cox's Orange Pippin and Lord Sumeld 

 atnonst apples is often severely crippled by scab, but on 

 other varieties the occurrence of this stage of the disease is 

 to be dreaded more from the spring-infections which it causes 

 than from any actual damage to the wood. 



Nature of Damage. In addition to the loss due to cracked 

 and deformed fruit and to the disfigurement of less infected 

 specimens, apple scab causes a considerable amount of damage 

 in a way less familiar perhaps to many growers. Scabbed 

 fruits keep badly. They shrivel and in many cases, owing 

 to the growth of moulds and other fungi entering through the 

 scab wounds, they rapidly decay. Once a fruit becomes rotten 

 any sound specimens in contact with it become similarly 

 affected. In this way considerable loss in storage may be 

 incurred. 



Susceptibility of Varieties. The degree of intensity with 

 which the fungus attacks the fruit varies considerably. 

 Difference in variety, soil, locality, and seasons are all 

 determining factors. Whilst all varieties are probably more 



