The Panama Disease. 
BY 
Ed. ESSED, B.Sc. (Edin.). 
With Plate XXVIII. 
I 
T HIS, disease broke out among the banana plantations in Panama 
about five years ago. Considerable damage to the crops was only 
done in a certain district, where the disease appeared when the fields were 
five to six years old. From certain spots it spread all around, affecting at 
last a considerable area. The fields, when ten years old, were absolutely 
worthless. Thirty miles from this district, however, the plague makes its 
appearance, but sporadically. 
In Costa Rica it badly rages only in spots ; there are still magnificent 
plantations covering an area of + 6o,ooo acres, where the disease does not 
spread and no real damage is done. 
In neither of these countries were such serious consequences experi- 
enced as in Surinam, where it appeared on fields but one year old, and the 
loss amounted to 25-75% °f the second and third crop. On some planta- 
tions even entire fields were annihilated. 
Different varieties of banana and plantain have been cultivated in this 
country for a century or more, but not so extensively as now ; and as they 
were grown for shade of other crops — the plantain for food at the same 
time — they were not allowed to remain any longer on the same field than 
two years. This is the main reason why the disease never attracted the 
attention of the planters, and it will explain why the attack became such 
a serious and general one as soon as the same areas were covered by 
extensive fields of one of the most susceptible varieties, the Gros Michel. 
As I was informed, the following varieties also are more or less 
susceptible : the Indian or Wine-coloured Banana, the Silverskin, the Apple, 
and the Horse Banana, the dwarf, and some varieties, unnamed, of plantain ; 
resistant were the Ladies’-finger, the Congo variety, and the ordinary plantain. 
The disease manifests itself by a peculiar withering of the leaves along 
the margin ; along a mid-dorsal line on the midrib discoloration may be 
observed. Sometimes only the bud (the youngest convolute leaf) withers, 
not being able to unfold, whereas the older leaves are healthy ; sometimes 
[Annals of Botany, Vol. XXV. No. XCVIII. April, 1911.] 
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