Columbia subject headings:
Agriculture--Africa, Sub-Saharan.
Food crops--Africa, Sub-Saharan.
Harvard subject headings:
Agriculture--Africa, Sub-Saharan.
Food crops--Africa, Sub-Saharan.
Indigenous crops--Africa, Sub-Saharan.
Traditional farming--Africa, Sub-Saharan.
Princeton subject headings:
Agriculture--Africa, Sub-Saharan.
Food crops--Africa, Sub-Saharan.