The Effect of Wheat upon the Incidence of Pullet Disease or Blue Comb

THE heavy feeding of wheat in many sections of the country and the continued incidence of “pullet disease” or “blue comb” in widespread areas would seem to justify an interim report and discussion of a limited number of field observations and experimental work conducted by the author at the Maryland Agricultural Experiment Station. The condition known as pullet disease (also termed X disease, blue comb, new wheat disease) was first described by Beaudette (1929) but despite the efforts of several investigators to transmit the condition from bird to bird, none appears to have succeeded. The possible exception is Waller (1942) who announced the isolation of a virus from acute cases which was not capable of producing death, hence he was unable to identify the virus as the sole etiological agent in pullet disease. Other investigators have proceeded without success along similar lines, and to the present time it is considered . . .