Objective. To evaluate the agronomic behavior of corn (Zea mays L.) experimental genotypes in three contrasting environments in the Central region of Chiapas, Mexico.
Design / methodology / approach. The experiments took place during the 2016 spring-summer agricultural cycle at Francisco Villa, Villaflores (730 m); San Luis, Suchiapa (600 m) and Ocozocoautla (800 m), at the Central region in the state of Chiapas, Mexico. At the three assessed sites, the climate is warm subhumid with rains in summer and intra-stival drought during the second half of July and the first half of August. The genotypes XT-5614, XT-3402, XT-5610, XT-5612, XT-5627, and BG7415W from the Biogene Company were evaluated, which are used in commercial crops at the Center of Chiapas. All genotypes showed viability greater than 90%. Three experimental sites were evaluated, in a randomized complete block design with four replications. The experimental unit consisted of four 5 m long rows 0.8 m apart. The useful plot was formed by two central furrows. The evaluated variables were: days to male flowering (DMF), days to female flowering (DFF), plant height (PH), cob height (CH), cob length (CL), cob diameter (CD), rows per cob (RC), grains per row and grain yield (YLD) at 14% moisture. These were analyzed with an analysis of variance (ANOVA) and for the genotype x environment interaction (GEI) the additive main effects and multiplicative interaction model (AMMI) were used, with the SAS statistical software and the GEA-R software.
Results: The combined analysis of variance detected differences between genotypes (G) for most of the variables except in grains per row. and days to male and female flowering; there were significant differences between environments (A) for all variables, while for the GEI, there were significant differences for the number of rows per cob. The CV was 1.26 (DFF) at 10% (YLD), which indicates an acceptable control (<20%) of the experimental variability. The results indicated genetic variation between evaluated genotypes, which allows the selection of the most outstanding ones. The evaluation environments showed differential effects and this condition is necessary for the evaluation of germplasm for a genetic improvement process.
Study limitations/implications: Cob height registered acceptable values given that short plants favor rotting in hot climates when weeds are present before harvest. The flowering of the genotypes was considered acceptable and was earlier (55 d) at the Suchiapa site.
Findings/conclusions: Among the assessed genotypes there were significant differences for grain yield, plant height, cob height, cob length and the number of rows; the genotype-by-environment interaction was not significant. The XT 5627 and XT 5610 genotypes showed higher stability, and the former showed higher grain yield. The highest yields were recorded in the environment from Francisco Villa, Villaflores, at the Frailesca region, Chiapas.