Florida Agricultural Experiment Station


mock lands is likely to throw the trees into a dieback condition.
One of the common methods of overcoming dieback on high
pineland and hammock land where cultivation is practiced is to
cease cultivation entirely or to cultivate as little as possible.
 Irregular moisture conditions in the soil is sometimes a factor
in the development of the disease. Dieback is more prevalent in
seasons following extreme drouth. Some such cases have been


 FIG. 7.-Dieback marked, or ammoniated fruit

traced to the overfeeding of the trees. A drouth was beginning
at the time of application of the fertilizer and continued until
near or after the second application. Owing to the dry condition
of the soil very little of the first application was made available
for use by the tree. When the rains came both applications were
made available at the same time, and overfeeding resulted.
 Groves planted on the spruce pineland or dune soils are sub-
ject to dieback. It is probable that the irregular moisture con-
dition in these soils is an important factor in the development of