AN ADAPTATION OF GRIFFING METHOD-IV OF COMPLETE DIALLEL CROSS ANALYSIS FOR EXPERIMENTS REPEATED IN SEVERAL ENVIRONMENTS

Griffing's method of complete diallel crosses, which evaluates only hy brids (method IV), was adapted for several environments. This methodol ogy is based on the following mathematical model: Y(ii'k) = m + l(k) g(i) + g(i). +s(ii') + (lg)i'k + (ls)ii'k + e(ii'k) ; i < i', where Y (ii'k) is the mean of the hybrid from the cross between the ith and i' th varieties of the group in the kth environment; l(k) is the kth envi ronmental effect' m, g(i), g(i), s(ii'), e(ii'k) are as described by G riffing (Aust. J. Biol. Sci. 9: 463-493, 195b); the remaining paramete rs correspond to the many interactions with environments. Parameter es timates and formulas to calculate sums of squares were obtained using a least squares method. An example is presented, related to a complete diallel carried out in two environments, concerning number of days to flowering of the common bean.