Florida Agricultural Experiment Station


stained, the branches may be so injured that they become defoli-
ated and may die.
 Marked or Ammoniated Fruit.-The same brownish, glossy,
gum-soaked areas that occur on the terminal branches also occur
on the rind of the fruit. (Figs. 6, 7, 8, 9.) They. may develop
on the fruit at any time after it is a month old and until it is
nearly full size. The areas rarely occur anew on very young
 fruits and never on the mature fruits.
 The stained fruit is spoken of as die-
 back-marked or ammoniated fruit. The
 term ammoniated arises from the
 fact that organic ammoniates, when
 used in excessive amounts as a fertil-
 izer, frequently induce the disease. The
 term is a misnomer, however, because it
 suggests that mineral ammonia fertil-
 izers may induce the disease. These
 sources are not known to induce it.
 When used in limited amounts they are
 useful in aiding the trees to recover.
 When used in excessive amounts on af-
 fected trees they may accentuate the
 disease.
 The stains or marks occur on the
 fruit in the form of spots and irregular
 areas. These markings are likely to be
 located anywhere on the rind, but are
 FIG. 3.-Gum pocket, more commonly found on the side or on
 (Indicated by arrow) the lower half of the fruit. The blos-
 som scar is often the center of a stained
 area. The surfaces of the areas may become cracked in a criss-
 cross manner like that of dried mud. (Fig. 9.) The areas form
 weak points thru which lines of splitting may occur. Dieback-
 marked fruit very commonly splits and drops. In severe cases
 this may occur so extensively that by the time the fruit should be
 mature there is very little left on the tree. The splitting and
 dropping often occurs to the greatest extent in midsummer at
 the time the fruit is beginning to take on size. Because the line of
 splitting may develop anywhere on the fruit that a stained area
 occurs, such split fruit is spoken of as dieback splits." (Fig.
 6.) This is to distinguish it from the splitting of normal fruit,
 which often occurs in the fall of the year. The splitting