Several new cotton seed treatments tested in 1985-86 showed promise of improving the management of the major seeding diseases caused by Rhizoctonia solani, Pythium species and Thielaviopsis basicola. Among the most promising were Rizoles and Baytan for R. solani and Systhane and Baytan for T. bascola. Baytan has exceptional activity against both R. solani and T. solani and when combined with Apron, this combination seed treatment is highly effective. Among registered cotton seed treatments, Apron for control of Pythium spp. and Chloroneb for R. solani, continue to provide excellent protection; when Imazalil is added, protection in some situations is provided against T. bascola. Greenhouse field tests also were made to compare various formulations, dosages and combinations of both registered and promising unregistered seed treatments for disease control. Experimental biological seed treatments, using a hard calcium gel matrix (alginate-pyrax-oat bran) as a carrier for the biocontrol fungi (Trichodera virde and Gliocladium virens) and bacteria (Bacillus subtilis), singly or in combination with Apron or Chloroneb, also have shown promise for management of cotton seedling diseases.