332 



PLANT DISEASES 



Matthews, Journ. Roy. Microscop. Soc, 1883, p. 321, 

 2 pi. 

 Smith, Diseases of Field and Garden Crops, p. 209, figs. 

 'Piaxik, Jakrb. d. Deutsch. Landwirth. Gesell., 1892. 



Fig. 91. — Fmarium heterosporum. i, portion of an 

 ear of rye showing diseased grains ; 2, diseased grains ; 

 3, portion of a diseased grain showing the dense clusters 

 of sporophores on its surface, sliglitlyx; 4, spores, 

 X3SO. 



FOOT-ROT OF ORANGE AND LEMON 



i^Fusarium Hmonis, Briosi.) 



A fungus causing considerable injury to orange and 

 lemon trees in Europe and the United States. Its pres- 

 ence is indicated by the exudation of masses of gum near 

 the base of the trunk. The diseased patches are small at 

 first, but gradually increase in size, spreading round the 

 trunk and passing into the roots, extending through the 

 bark and cambium into the wood, killing the tissues. At 

 the same time the leaves are few in number, small, and 

 yellowish, and many of the smaller branches die. 



