FURTHER OBSERVATIONS ON ANGUILLULINA DIPSACI IN RHUBARB

S ummary Continued field observations on disease in rhubarb accompanied by infection by Anguillulina dipsaci are recorded. The symptoms, both in the foliage and in the root stock, are similar to those described for bacterial crown rot by Millard. In infection experiments using the rhubarb strain of A. dipsaci symptoms of disease similar to those found in the field were reproduced in rhubarb seedlings and setts. The course of eelworm infection in the young leaves and in the crown in these experiments is recorded. Host transference experiments have shown that the rhubarb strain of A. dipsaci is not rigidly restricted in its feeding habits for it is capable of producing persistent infection in oats, pea and chickweed. It is also capable of producing only temporary infection in cabbage and mangold. Infection is also recorded in Rumex spp. but insufficient evidence is available as to its persistence on these hosts. Incidence of A. dipsaci is recorded in rhubarb from Scotland and southern England in addition to Yorkshire.