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CHAPTER XIII. 



DISEASES AND INSECT PESTS. 



MAL-DI-GOMA. 



One of the worst diseases of citrus trees in America 

 is mal-di-goma, or foot rot. It is also prevalent in 

 Australia, although not to so great an extent. Foot 

 rot attacks citrus trees at the crown roots, extending 

 a foot or so above the ground and downward among 

 the roots. The presence of the disease is first noticed 

 by the discharge of gum at the diseased spot. Later 

 on the bark rots away, and the tree eventually dies. 

 The disease seems to be caused either by water standing 

 around the roots, the crown roots becoming injured 

 through Careless cultivation or otherwise, or too deep 

 planting. As these matters rest greatly in the hands 

 of the grower, the careful orchardist will see that his 

 trees do not needlessly suffer from these causes. 

 Where the land has to be flooded to water the trees 

 the trees should be budded on the Seville stock, as 

 experience has amply proved that both sweet orange 

 and lemon stock are liable to suffer from foot rot if 

 planted in wet situations. 



Affected trees should have the earth removed from 

 around the main roots, the decayed portions of the 

 bark cut clean away, and after the ground has been 

 well aerated, fresh soil obtained from outside of the 

 citrus plantation should again be placed around the 

 roots. 



MOTTLED LEAF. 



A 



A disease that has been doing considerable damage 

 to some of the citrus plantations of the Hurray Valley 

 during recent years is that known as "mottled leaf." 



