F. J. F. SHAW 55 
Plots M and N. These plots, each about 4th acre, were selected in good 
land which had never carried jute before. Plot M was sown on 5th March 
with seed of ‘‘ kakya bombai’’ which had been treated by steeping in copper 
sulphate solution, and Plot N was sown on the same date with seed which had 
not been so treated. Both plots gave an excellent crop of jute 9-11 feet in 
height. In both plots nearly the same number of stems were diseased owing 
to D. Corchori—i76 stems in Plot M and 56 in Plot N. 
As a result of these field experiments, particularly from a consideration of 
Plots M and N in 1919, it cannot be said that seed steeping in a solution of 
copper sulphate has any influence on the severity of the disease, and, therefore, 
as mentioned above, the dissemination of the disease cannot take place to 
any appreciable extent through spores of D. Corchori mingled with the jute 
seed. The percentage of disease was also not to any extent greater in those 
plots which had been under jute for two or more successive seasons. 
Conclusions. 
The present investigation has shown that— 
(1) Diplodia Corchori Syd. is a parasite of the jute plant. 
(2) The disease occurs after flowering and threatens the seed crop. 
(3) The fungus is widely distributed in jute-growing districts. 
(4) The intensity of the disease varies greatly from one season to 
another. 
(5 The disease is most severe on large, well-grown stems, and infection 
takes place more readily upon green-stemmed than upon red-stemmed 
varieties. 
Further research is required to show the precise mode of infection, the 
limits of temperature and humidity under which infection will take place, and 
the qualities which render the late sown crop resistant to the disease. Direct 
treatment against a disease such as this is scarcely possible in the case of the 
jute crop, and we must look to an increased knowledge of the factors which 
condition success in the life of the parasite, and to the possibility of modifying 
these factors by alterations in the culture of the host, for the effective control 
of this disease. 
Any disease which threatens the jute plant might, in view of the impor- 
tance of this crop in the economic life of Bengal, become a factor of grave 
agricultural importance. It is a matter of congratulation that the crop is 
generally free from fungal disease and that the parasite, which forms the 
