Influence of Tillage, Seed Quality, and Fungicide Seed Treatments on Cotton Emergence and Yield

Seedling diseases of cotton (Gossypium hirsutum L.) limit production in the High Plains of Texas. Field studies were conducted from 1992 through 1995 to determine the influence of tillage (conventional or terminated wheat [Triticum aestivum L.] conservation tillage system), seed quality, and fungicide seed treatments (specific for Rhizoctonia solani, Pythium spp., and Thielaviopsis basicola) on cotton emergence and lint yield. Seed quality positively affected plant emergence and yield in all years. Increases in plant emergence and yield were generally found with conventional rather than conservation tillage. Emergence 21 d or later was generally lower for untreated seed or Captan (C) (N-trichloromethylthio-4-cyclohexene-1,2-dicarboximide) treated seed than seed treatments that included triadimenol (Baytan 30 [B]) (Beta-(4-Chlorophenoxy)-alpha-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol) in 3 of 4 yr; carboxin-PCNB (Vitavax-PCNB [V]) (5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-3-carboxamide-Pentachloronitrobenzene) in 2 of 3 yr and metalaxyl (Apron 2.66F [A]) (N-(2,6-dimethyl-phenyl)-N-(methoxyacetyl)alanine methyl ester) + C in one year. Yields were affected by seed treatments in 3 yr, with B being associated with higher yields every year, and lower yields associated with chloroneb (Nuflow ND [N]) (1,4-dichloro-2,5-dimethoxybenzene) + TCMTB (2-(thiocyanomethylthio) benzothizaole (1992), untreated seed (1994) and C (1995). Plants were infected most frequently with R. solani and T. basicola. The most consistent factor affecting seedling disease was seed quality. Conventional tillage and seed treatments specific for Rhizoctonia and Thielaviopsis improved seedling emergence and yield most years. Interactions between chemical seed treatments, seed quality, and tillage systems were inconsistent between years and even among different evaluation times in the same year.