92 THE BANANA 



Drost has shown by infection experiments that the 

 Surinam Panama disease is due to a fungus named 

 Leptospora musce, which has Cephalosporium and Fusarium 

 stages in its life-history. It can penetrate the root-hairs, 

 and thence spread into the central bundle of the roots, 

 whence it passes into the root-stock and ascends the 

 vascular bundles of the leaf -sheaths. Usually, however, 

 it attacks directly the bundles exposed at the place where 

 the suckers have been cut from the mother plant, under 

 the surface of the soil. The fungus is not as a rule found 

 in the leaf -blade or in the fruit-stalk. 



India. A disease of bananas was reported in April 

 1911 by S. K. Basu* as occurring near Chinsurah, Bengal. 



The variety of banana known as Kanthali suffered much, 

 but the most profitable variety, known as Martaman, 

 suffered most, so much so that this variety of banana has 

 become practically extinct in these localities. The 

 varieties known as Champa and Kuncha (the latter being 

 used green as a vegetable) are free from all attack of this 

 disease. 



The chief symptoms of the disease are : (1) The turning 

 yellow of some of the older though otherwise healthy 

 leaves ; (2) the formation of one or more much reduced 

 leaves at the crown ; (3) the gradual withering of the 

 younger leaves ; and (4) finally the breaking down of the 

 plant. The disease progresses so rapidly that in ten or 

 fifteen days from the first appearance of it the plant is 

 found dead. 



By cutting a plant transversely near the base of the leaf- 

 sheath, the disease becomes noticeable either as black, 

 brown, or yellow spots, varying in size from that of a circle 

 three or four inches across. In longitudinal sections these 

 spots appear like streaks, which seem to pass from the 

 roots upwards into the root -stock and the leaf -sheaths. 

 In many places where a young plant is still attached to 

 another plant the disease passes from the mother plant 

 to the young offshoot directly through the point of contact. 

 * Quarterly Journ, Dept. of Agric., Bengal, iv. 196. 



