DETERMINATION OF CORN HYBRIDS ADAPTABILITY USING GGE BIPLOT ANALYSES. AZUERO, PANAMA, 2002.

Abstract

With the objetive of recommending the outstanding corn cultivars in the country was carried out an experiment throughout 11 contrasting environments in the Azuero Region. The genetic materials of this trial consisted of 16 experimental White and yellow hybrids of the IDIAP, PRM and of the companies Pioneer, Monsanto and Cristiani Burkard. A Complete Randomized Block Design with three replications was used. The experimental plots consisted of two rows of 5.2 m of length, separates by 0.8 m. A combined analysis of variances was done and the means was separated by the Least Significant Differences (LSD). To estimate adaptability and stability of hybrids to the environments, it was used the Additive Main effects and Multiplicative lnteraction (AMMI) and Biplot GGE technique (Genotype plus Genotype-Environment interaction). The statistical analysis indicated significant differences (P<0.01) among genotypes, environments and the genotype-environment interaction indicating the differential response of hybrids at different environments. The hybrid group formatted by C-8007, X-1358K, 30K-75 and P-0102 outstanding by its high yield and well agronomics characteristics throughout all environments. The stability analysis identified al C-8007, X-1358K and P-0102 like to most stables. The same analysis identified three environments groups associated mainly to planting date and the number of harvested plants. The first environmental group was formed by the El Ejido site. The second group included the five sites planted before September 10 and the third by the sites planted after this date. In the second group, a high yield was observed (mean of 6.8 t/ha), overcoming significantly to the third environmental group (mean of 4.38 t/ha). Due to the rainfall scarcity on November and December, the trials planted before September 10, escaped during the grain filling process to the hydric stress at the present year. The El Ejido experiment, in spite of it was sowed on August the yield (5.48 t/ha) was affected by the low number of harvested plants (mean of 4.83 plants/m²). According to stability analyses this site was completely different to the both environmental groups mentioned previously.