Three high tannin lines (86E3, 86E8, and 86E20) and two commercial varieties (Stoneville 213 and TAMCOT CD3H) were crossed in a half-diallel mating scheme in 1987. Tannin concentration among the parents and the F₁'s was determined during two growth stages: first bloom and at two weeks after first bloom. Leaf discs from the topmost open leaf and the true leaf on the 6th main stem node from the terminal were used as samples. Analysis was done using the HC1-butanol method.

Stoneville 213, TAMCOT CD3H, 86E20, and crosses involving these three genotypes had higher tannin content in the topmost open leaf than the other entries during first bloom and at two weeks after first bloom. Tannin concentration of the true leaf on the 6th main stem node from the terminal was relatively higher for 86E20 and all crosses made with this line as a parent.

Tannin concentration of the topmost open leaf was higher at first bloom than at two weeks after first bloom. On the other hand, first bloom tannin content of the true leaf on the 6th main stem node was lower than at two weeks after first bloom. Generally, topmost leaf had higher tannin content than the 6th leaf.

Of the five genotypes evaluated, 86E20, TAMCOT CD3H, and Stoneville 213 had positive general combining ability effects for first bloom and at 2 weeks after first bloom. For the true leaf on the 6th main stem node, 86E3 and 86E20 had positive general combining ability effects for tannin content at both stages. Specific combining ability effects were not significant.