-^^~^] A Little Known Vetch Disease 



85 



PLATE ;-J 

 Figs. 13, 18, 19, and 20, are drawn to tlie same scale; the magnification of Fios 



14-17, inclusive, is alike. " 



Fig. 13. Acervulus in cross section of Protocoronospora on vetch stem The 



stroma extends 3 to 4 host cell layers in depth. 

 Fig. 14. Multinucleate mycelium taken from the margin of an acervulus 

 Fig. 15. Variation in size and shape of conidia and in the number of nuclei 

 liG. 16. Multinucleate cells from beneath the stroma. 

 Fig. 17. Multinucleate conidiophores and cells of the stroma. 

 Fig. 18. Germination of conidium on upper leaf surface of hairy vetch. The 



formation of the appresorium is followed by infection within 36 to 48 hours 

 Fia 19. Infection through the epidermis on the lower surface of the leaf 

 Fig. 20. Penetration by conidia lodged on the upper leaf surface. 

 Fig. 21. A surface view of an acervulus six days after inoculation. 



PLATE 4 

 Fig. 22. Colonies of Protocoronospora nigricans, one week old, on vetch de- 

 coction agar. 

 Fig. 23. Two week's old cultures on the same medium. 



PLATE 5 

 Fig. 24. Lesions on leaves of hairy vetch. 

 Fig. 25. Stones with elongated, dark brown to black lesions. 



PLATE 6 

 Fig. 26. Pods showing the oblique oblong lesions typical N)f false anthracnose 

 ±IG. 27. Young lesions with whitish centers on young pods. The pod at the 



extreme left of the series had purplish discolored areas but fruit bodies 



of the causal organism have not yet been formed. 

 Fig. 28. The dark oblique areas are lesions on mature pods. 



