The efficiency of new chemical and biological seed dressings and in-furrow treatments was evaluated against standard controls of cotton seed and seedling diseases. Trials were conducted in fields in several locations in the San Joaquin Valley and in the greenhouse. Of the materials tested, including some biological agents, no material approached the efficacy of Apron for the control of Pythium-induced damping-off. Seed dressings of Nu-Flow M, Maxim, and fluazinam reduced seedling disease in Rhizoctonia-infested soil. In some trials each performed favorably to the standard seed treatments, Nu-Flow ND and Vitavax-PCNB. Black root rot, caused by Thielaviopsis basicola, was best controlled by Baytan, followed by Nu-Flow M; no other materials provided adequate control. Several biological control agents failed to reduce seedling disease.