Results of this three-year testing program in the San Joaquin Valley indicate that Verticillium wilt damage to cotton may vary from one area to another—but when wilt symptoms appear by mid-season, the wilt-tolerant Acala 4-42 variety will significantly outyield the two susceptible varieties, Cal 7 and Deltapine Smooth Leaf. When cotton is grown continuously on the same plots, more drastic declines in yield occur with with-susceptible varieties than for Acala 4–42.

Miravalle and Turner are also Research Associates in the Agricultural Experiment Station, Department of Agronomy, University of California, Davis.