See: Varietal Publication No. CXXVI, March,
1988
Mecca has high resistance to spotted alfalfa aphid, pea aphid, Southern root--knot nematode, and Fusarium wilt; moderate resistance to blue alfalfa aphid and Phytophthora root rot; and low resistance to bacterial wilt, anthracnose, and stem nematode. Its reaction to Verticillium wilt has not been determined.