Bulletin 229, Diseases of Citrus in Florida


been published previously in various periodicals, while others
are published here for the first time.
 The majority of the illustrations are published for the first
 time, most of these having been made by the senior author.
 The others, except where special acknowledgment has been made,
 have been taken from former publications of this Station and
 the files of the department of plant pathology. The illustrations
 for figures 82 and 84 have been reproduced from Hume's book,
 "The Cultivation of Citrus Fruits," by permission of The Mac-
 millan Company.
 The authors desire to express their appreciation to Dr. H. S.
 Fawcett, of the California Citrus Experiment Station, who read
 the preliminary draft of the manuscript for this bulletin in 1927
 and kindly offered a number of valuable suggestions. They are
 also indebted to a number of colleagues of the Florida Agricul-
 tural Experiment Station and State Plant Board who have also
 read various drafts of the manuscript and offered helpful sug-
 gestions and advice.

 GENERAL CONSIDERATIONS IN THE PREVENTION
 OF CITRUS DISEASES
 The successful control of citrus diseases often depends on
 preventive and precautionary measures taken far in advance of
 the appearance of the trouble. Before the land is plowed or the
 trees are planted, certain measures often can be taken to avoid
 troubles in the future. Precautionary measures frequently can
 be included in selecting the grove site and rootstock, in providing
 drainage or irrigation, and in the general grove practices,
 which will greatly reduce the chances for disease invasion. The
 more important of these subjects which have some bearing,
 either directly or indirectly, upon the probable occurrence of
 diseases in the grove have been briefly considered in the follow-
 ing subdivisions of this section.

 GROVE LOCATION
 In selecting the site for a grove, special consideration should
be given to the soil type, subsoil, need for drainage, susceptibil-
ity to drought, and protection from storms and cold, since all of
these factors may have considerable bearing on the disease situ-
ation. Although groves most favorably located will generally be
troubled more or less with certain diseases, those in less favor-