Florida Agricultural Experiment Station


of fruit. As a rule, it affects chiefly the older leaves but, in severe
cases, may occur even on the last-formed leaves. Outbreaks of
the trouble appear to vary greatly in intensity from year to year.
 Although considerable study of this trouble was made by
 Floyd several years ago, nothing definite was learned concerning
 its cause. Recent field observations by the senior author indicate
 that yellow spot may be merely a preliminary stage of greasy
 spot, since the latter trouble is often associated with the former.
 Where of extensive occurrence, yellow spot results in con-
 siderable premature defoliation.
 Since the trouble appears to be
 K associated most frequently with
 trees that have become weaken-
 -. eed from one cause or another, a
 generous application of some
 quick-acting nitrogenous fertil-
 izer should prove beneficial to
 trees exhibiting it.
 STAR MELANOSE
 Peculiar markings, similar to
 melanose markings in their col-
 or and raised character but
 characterized by the fact that
 many of them are more or less
 stellate, or star-like, in outline,
 occur occasionally on citrus foli-
 age (Fig. 81) and rarely on the
 fruit. Star melanose has been
 observed in Florida on the foli-
 age of orange, grapefruit, and
 lime trees. According to Win-
 ston, Bowman, and Bach, it also
 occurs on the fruits of the first
 two.
 The markings occur on either
 surface of the leaves, although
Fig. 81.-Star melanose on orange more commonly on the upper
 leaf following spraying with
 bordeaux mixture. one. They may be numerous, or
 few and widely scattered. The
individual markings vary from minute, rounded, melanose-like
markings to variously split eruptions as large as 3/32 inch in