Volutella Species on Alfalfa

SUMMARY

Three species of Volutella infest forage legumes in the Ames vicinity. Two of these, V. gilva and V. ciliata, are saprophytes, the latter not previously reported from the U.S. The sporodochia are bright colored and superficial, typical of the genus. The third species, V. colletotrichoides, a newly described facultative parasite of several forage legumes, is believed to have been introduced with seed lots of the Plant Introduction Station. This fungus, which produces sparse black setae and superficial sporodochia, was distinguished from the genus Colletotrichum because of the small conidia and superficial nature of the fruiting body. Several isolates from field-inoculated alfalfa consistently produced densely setose sporodochia but did not differ in conidial size and shape. This form was named V. colletotrichoides var. setosa.

V. colletotrichoides did not show indication of severe pathogenicity to any plant tested. No detectable spread or increase in the field during two years was observed, indicating little likelihood of the fungus becoming of economic importance.