7 
plants on loose, sandy soils of perfect drainage became strongly chlo- 
rotic. It was thus apparent that although the trouble was intensi- 
fied by poor drainage, faulty drainage was not the primary cause. 
The appearance of patches of chlorotic plants in the midst of 
fields that were for the most part green and vigorous made it seem 
probable that it was a bacterial disease. But investigations by the 
pathologist failed to reveal any bacterial or fungus disease. The 
fact that chlorotic plants on transplanting to different soils in every 
case recovered also militated against this view. Chlorotic plants and 
soil were secured from three different plantations and placed in pots. 
The chlorotic plants in the original soil in all cases remained without 
change, while those placed in a river sand became, in a short time, 
green and healthy. Also, since these investigations were started 6 
acres of chlorotic plants have been taken up and set out in soil of a 
different character. Here they became green within a month or two, 
and, in the year that has elapsed since transplanting, not a single 
plant has developed the chlorosis. Had the plants been infested with 
bacteria or fungi they could hardly have shown such a uniform 
recovery on transplanting to different soils of a similar physical 
character. 
Experiments with commercial fertilizers and stable manure were 
tried in 1904 and 1908 by the horticulturist on two of the plantations, — 
where the chlorosis was very marked, to see whether the trouble could 
have been caused by lack of nutriment. 
It was found that although the complete fertilizers improved the 
condition of the plants slightly, they were without much effect. The 
stable manure produced slightly more improvement than the com- 
mercial fertilizers. 
It being, then, seemingly impossible that the chlorosis could have 
been produced by disease, lack of nutriment, poor drainage, or injury 
from the sea, it was thought probable that the cause was to be found 
in the unsuitable chemical character of the soil. Accordingly, soils 
were collected from all the areas where the chlorosis occurred and 
from adjacent fields where the pineapples were doing well. In some 
cases patches of a few hundred chlorotic plants occurred in the midst 
of several acres of healthy green plants. Hence, it was to be expected 
that, if the trouble was due to the chemical character of the soil, a 
difference would be apparent in the analyses of the soils where the 
healthy and unhealthy plants were growing. In addition to such 
comparative analyses, analyses were made of most of the well-drained 
soils where pineapples were growing well. It was thought that, 
should the soils producing chlorotic plants show a chemical character 
that adjacent areas with healthy plants did not, and should none of 
the good pineapple soils show the same characteristics as the bleached 
areas, the specific cause would become apparent. 
[Bull. 11] 
