Abstract

A

study was conducted to estimate the stability (AMMI) and the

confidence or normalized response (RNI) for a white corn

hybrid, assessed in a regional PCCMCA corn trial from 1998 to

2000. In this period, 100 genotypes were evaluated at 48

environments at nine Central America and the Caribbean

countries. The RN1 values represents the specific genotype.s

probability increase over the mean yield, specified by a control.

The study allowed to identify genotypes with low environment

interaction and of normalized response varying from good to

average (0.6 ≥ RNI < 0.9) according with the control. The

stability and the confidence degree, regarding to the regional

control HB-83, was determined every year. In addition, the

same analysis was performed with 12 genotypes in common at

least in two year of this phase. The combined analysis indicated

that 25% of genotypes showed a RNI = 0.8, these genotypes

were CM 933-133, XM 7706 and XM 7708. Six of them (50%)

showed standard RNI, outstanding the H-59 and CB-HS-9 with

RNI values of 0.73 and 0.75, respectively; the other 25%

presented low RNI, less than 0.6. The HB-83, CB-HS-11, HN-

12 and Trop E 103 were identified as hybrids with low

genotype-environment interaction by the AMMI analysis. Both

analysis allowed to verify that HB-83 is still a competitive and

current regional control due to its high production and good

stability throughout contrasting environments.