Two Spanish peanut cultivars (SN 55–437 and Tamnut 74), two Spanish germplasm lines (TxAG-4 and TxAG-5) with partial resistance to Pythium myriotylum and Sclerotinia minor, and one early maturing runner-type cultivar (Langley) were compared for three years under nonirrigated conventional-tilled, reduced-tilled, and no-tilled culture. Yield, percentage sound mature kernels + sound splits (SMK+SS), and southern blight disease comparisons were made to ascertain if certain cultivars or genotypes would be beneficial to peanut production under reduced-tilled systems. Tillage x genotype interactions were not statistically different. When the yields and percentage SMK+SS for no-tilled entries were averaged, it was found that they were lower than the other tillage systems one out of the three years. Neither southern blight nor pod disease, caused by Sclerotium rolfsii, were yield-limiting factors in any of the production systems. However, genotypic differences were apparent for yield and percentage SMK+SS; TxAG-4 was consistently among the best yield performers, while the yield of SN 55–437 was consistently low. Tamnut 74 and TxAG-4 produced lower percentage SMK+SS than the other entries in two of the three years of the test.