Upon the outbreak of the Pacific War, Pres. Quezon re-appointed Secretary Rafael Alunan, Sr. (1941-1942) as Secretary of Agriculture and Commerce.
After the Japanese liberalization on July 4, 1945, the government rebuilt the country and reconstituted the agencies including the Department of Agriculture and Commerce (DAC).
With the resumption of the Commonwealth Government, President Sergio Osmeña reappointed Vicente SingsonEncarnacion as Secretary of the DAC.
Thereafter, Mariano Garchitorena (1946-1948) was appointed by President Manuel Roxas.
In 1947, the Department was renamed as the Department of Agriculture and Natural Resources (DANR).
In September 1948, President ElpidioQuirino appointed Placido L. Mapa as Secretary.
Two years later, Vice President Fernando Lopez served concurrently as the DANR chief. During his term, the Bureau of Agricultural Extension (now Agricultural Training Institute) was established, along with the organization of the 4-H Clubs and Rural Improvement Clubs (RICs) nationwide.