300 PLANT DISEASES 



Bolley, Bull. No. 4 and No. 9, N. Dakota Agric. Expt. 

 Station, 



Arthur, Indiana St., Bull. No. 65, pp. 19-36. 



BROWN ROT OP FRUIT 



( Monilia fructigena> Pers.) 



One of the commonest and most widely distributed of 

 moulds against which the fruit-grower has to contend. It 

 attacks apples, plums, cherries, and other kinds of orchard 

 fruit, and is also common on various wild fruits belonging 

 to the Order Rosaceae. 



In Britain it is most frequently seen on apples, and 

 although best known to the casual observer on the fruit, 

 occurs also on the young shoots, leaves, and even the 

 flowers. 



On the leaves, where the fungus usually appears in the 

 spring, it forms thin, velvety, olive-brown patches, consist- 

 ing of chains of barrel-shaped spores, originating from the 

 mycelium present in the tissues of the leaf. At maturity 

 the spores become free, and are carried by rain, wind, 

 insects, or birds on to the surface of healthy leaves or young 

 fruit, where, if conditions are favourable, a new disease- 

 spot is formed. 



On the fruit the first indication of disease is indicated 

 by the appearance of brownish scattered patches on the 

 skin. This is followed by the appearance on the surface 

 of small tufts composed of chains of spores. As the disease 

 extends, the tufts of spores are usually arranged in irregular 

 circles round a central starting-point. 



