F. J. F. SHAW 53 
inhibit the germination of the spores of D. Corchor’. In 1918, and in 1919, therefore, 
the whole of the jute seed crop of Bihar was disinfected in this manner before 
despatch to Bengal, and in these years the experiments detailed below were carried 
out in Pusa and the vicinity to test whether this treatment had any effect on the 
incidence of the disease. . 
In 1918 the following field experiments were made :--— 
Plots A and B. Two plots, each about j5th of an acre, were sown on 
5th March with jute seed (‘‘ kakya bombai”’) obtained from the diseased Pusa crop of 
1917. This seed had not been treated by steeping in copper sulphate solution: 
but the land had not been under jute for over 20 years and no other jute was in 
the vicinity. One plot (A) was thinned out to a distance of 18” between plants, 
the other plot (B) was not thinned. Both plots gave a good crop. In the crop 
which had been thinned out the plants reached a height of 14 feet and a thickness 
of 1-14 inches, but in the crop which was not thinned the plants only reached a 
height of 8 feet and thestems were much thinner. The plots were kept under obser- 
vation throughout the season, and were cut and harvested on 5th November ; 
the Diplodia disease was practically absent, only some half dozen infected plants 
occurring in each plot. 
Plots C and D. These were a repetition of the two previous plots, Plot C 
being thinned out, and gave the same result. 
From these experiments in which disease-free soil was sown with untreated 
seed, and in which the disease failed to appear to any appreciable extent, it 
may be inferred that the spread of the disease through spores mingled with the 
seed is not very serious. 
Plots E and F. Two plots, each about ith acre, were sown with treated 
jute seed (“‘kakya bombai”’) on Ist March. The plots were situated in a portion 
of the field in which jute had been grown during the previous season and where 
the disease had been particularly bad. Unfortunately owing to deficiency of 
moisture during March and April, the seed did not germinate and the plots had 
to be resown at the end of April. Germination when it did take place was 
late and the crop in size and appearance resembled the ordinary late sown 
crop. Owing also to irregularity in germination in both plots the plants 
were fairly widely separated and the original intention of thinning out one 
plot was useless. Both these plots showed more Diplodia disease than the 
previous plots. Thus Plot E had 67 plants infected with Diplodia and Plot F 
had 54 plants infected with Diplodia. 
In this experiment, therefore, a crop, which was virtually a late sown 
crop grown from treated seed, developed the disease when grown in land 
which had carried diseased jute during the previous season. 
: 2 
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