184 DISEASES OF ECONOMIC PLANTS 



Upon the strawberry it induces curled, inrolled leaves 

 and the white mycehum is found upon their lower surfaces. 

 The disease is not usually very troul)lesome. 



TROPICAL FRUITS 

 AVOCADO 



Anthracnose (Colletotrichum glcesporioides Penz.). — 

 Attack upon the leaves eventually causes defoliation. 

 Early infection of the fruit results in its complete loss. If 

 the fruit is not attacked until late, it may remain upon the 

 tree, but becomes spotted with brown and finally cracked. 

 On both leaves and fruit it can be controlled by the use of 

 Bordeaux mixture. 



CITRUS FRUITS 



Brown rot (Pythiacystis citrophthora Sm. & Sm.). — 

 This fungous disease has caused a very considerable loss, 

 30 per cent in some cases, in California for the past seven 

 or eight years,^ but the real cause of the trouble was not 

 known until 1906 or 1907. It chiefly affects the fruit after 

 it has been packed and shipped to market, although the 

 infection takes place in the orchard or packing-house 

 where the disease is largely disseminated by the fruit 

 washers. 



The rot has a pecuUar characteristic rancid penetrating 

 odor, and its presence is further indicated by an abundance 

 of small flies in boxes where there is any diseased fruit. 

 One affected fruit in a box communicates disease to the 

 whole. 



' Smith, R. E., Cal. Agr. Exp. Sta. Bui. 190, July, 1907. 



