X-disease

At the time of its first occurrence, nothing was known about the cause of X-disease or whether it could be treated and cured.

1954, United States. Agricultural Research Service, Hyperkeratosis (X-disease) of Cattle, page 5

Crankcase oils may contain chlorinated naphthalenes, which have been reported to contribute to "X-disease" (hyperkeratosis) in cattle.

1983, Comparison of Wood Preservatives in Stake Tests, page 128

For example, a 1940s claim attributed to DDT, without a shred of evidence, a mysterious cattle disease known as X-disease (discussed further in appendix 4).

2016, Donald Roberts, Richard Tren, Roger Bate, The Excellent Powder: DDT's Political and Scientific History, page 187

Transmission of X-disease was more erratic with peach than with chokecherry buds, possibly because only low titers of the X-disease mycoplasma-like organisms (MLO) are present in infected peach trees during most of the year.

1977, The Plant Disease Reporter, page 1024

A number of other yellows diseases of trees are of major importance throughout the world either because of local impact or widespread distribution. Among these are Prunus X-disease, pear decline, elm phloem necrosis, apple proliferation, the witches'—broom diseases of paulownia and jujube, and the greening and stubborn diseases of citrus.

2012, Karl Maramorosch, Mycoplasma Diseases of Trees and Shrubs, page 35