The degree to which plant diseases may develop in 1963 and the amount of losses that may result will depend on several factors. These include the weather, growth stage of plants and presence or absence of disease causes.
Worf, Gayle L.
"Plant Disease Outlook for 1963,"
Iowa Farm Science: Vol. 17
, Article 4.
Available at: https://lib.dr.iastate.edu/farmscience/vol17/iss7/4