INTERPRETIVE SUMMARY

dahliae, is a widespread disease that occurs in most cotton-producing areas. V. dahliae is a soil-borne pathogen that infects plants through the roots. Symptoms of infected cotton plants include stunting and wilting by some strains of V. dahliae and defoliation by other strains. The purpose of this research was to determine the potential of cotton seed treatment with biological control strains of Trichoderma virens to induce resistance to the fungal wilt pathogen, Verticillium dahliae, injected into the stem of cotton plants. Trichoderma virens is an effective biocontrol agent against soil-borne seedling diseases of cotton, but its ability to protect cotton against other diseases is unknown. Because another Trichoderma species, T. harzianum, i