94 . Circular N0. 16. ‘ . , V
' crop for twenty years, so it was evident that the disease was j
introduced with the seeds. Of the seeds left over from the c
planting twenty per cent were found diseased. I c
1 Anthracnose is a well known disease, the result of the f
attacks of a parasitic fungus often very destructive to both 1
garden and iield beans. lt attacks pods, leaves and stems, but i ‘°
is not so often recognized on the two latter as when damaging —
the pods. The infection appears as minute purple dots, with an l g
T obscure darkening of the general green hue of the pod immedi- (
i T ately about them. The affected surface becomes decidedly 1
T .. sunkenas the dots increase in size, then the centers become 1 i
· black, and tinally as the minute fruiting parts develop this 1
i gives way to a central gray or pink region. Spots may in- . i
crease to a quarter of an inch in diameter, then merge with ]
spots near-by _and eventually affect _much of the pod. The l
r growing threads of the parasite push into the interior so far, 1
1 , after _a time, as to reaelrthe seeds, and leave purple or dusky I 1
. 'marks on them. The fruiting bodies are microscopic in size
and arc producedin great numbers. \Vhen wet they adhere i
_ to whatever touches,them, and are thuslcarried about by those V
working among the plants as well as by rain, and probably in “ _
i dry weather by currents of air. Once started in a planting: ,
· there is thus a prospect of further spread by these agencies.  
The chief agency by which the disease is scattered ever  
the country and perpetuated is undoubtedly the seeds. Most »
or those who have studied the ailment have been impressed .
with this l'aet. .\nd while beans carrying the parasite are not 4
in all eases recognizable, many such lots are, and these shoulf
never be planted unless first gone over and all seeds recogniz-
able as diseased are thrown out and burned.
Treatment of suspected seeds with a fungicide has been
advocated, and would probably be of more value if the fun- ,
gus were eoinpletely exposed on the surface in all cases. Con-
sidering the fact that the parasite may be concealed within the
seeds it is not ealeulated to be an entirely satisfactory treat-
ment, tho it would disinfect the surface and thus, in con- .