AGRONOMIC BEHAVIOR OF ZEA MAYS L. MAIZE GENOTYPES EVALUATED IN THE WARM DRY REGION OF CHIAPAS, MEXICO

Abstract

Abstract: The objective of the present investigation was to evaluate the agronomic performance of experimental genotypes of maize in three agro-ecological environments of the Centro de Chiapas region. During the spring summer 2016 agricultural cycle, six maize genotypes were evaluated in a randomized block design with four replications. The genotypes showed significant differences (P <0.05) for grain yield, plant height, ear length and number of rows; the interaction genotype by environment was not significant. The XT-5627 and XT-5610 genotypes showed greater stability and the first showed higher yield. The high yields were obtained in the Francisco Villa, Villaflores environment, of the Frailesca region, Chiapas.

Objective: The objective of this research was to evaluate the agronomic behavior of experimental maize genotypes in three contrasting environments of the Central region of Chiapas.

Design/methodology/approach: The experiments were established during the spring-summer 2016 agricultural cycle in the towns of Francisco Villa, Villaflores (730 m); San Luis, Suchiapa (600 m) and in Ocozocoautla (800 m), located in the Central region of the state of Chiapas. In the three sites, the climate is warm subhumid with rains in summer and presence of intra-festival drought during the second half of July and the first half of August.

 Genetic material. The experimental genotypes were evaluated: XT-5614, XT-3402, XT-5610, XT-5612, XT-5627 and the BG7415W genotype of the Biogene company, which is used in commercial crops in the Center of Chiapas. All genotypes showed viability greater than 90%. The genotypes were distributed in the three experimental sites, which were used for seeding in a randomized complete block experimental design with four replications. The experimental unit consisted of four rows of 5 m in length each and 0.8 m apart, while the useful plot was formed by the two central rows.

Variables evaluated. Days to male flowering (DFM), days to female flowering (DFF), plant height (AP), ear height (AM), ear length (LM), ear diameter (DM), rows per ear (HM) , grains per row and grain yield (REND) at 14% moisture. A combined analysis of variance (ANOVA) was carried out and the model of additive main effects and multiplicative interaction (AMMI) was used for the evaluation of the genotype x environment interaction (IGA). The analysis of variance was solved with the SAS system (SAS, 2000) while the GEA-R program was used for the AMMI model (Pacheco et al., 2015).

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; Between environments (A) there were significant differences for all variables, for the environment genotype interaction (IGA), there were only significant differences for the number of rows per ear (Table 1). The values of the coefficient of variation (CV) were from 1.26 (DFF) to 10% (REND), which indicates an acceptable control (<20%) of the experimental variability. The results show a genetic variation between the evaluated genotypes, which allows selecting the most outstanding ones. The evaluation environments represent the agroecological conditions, where maize is grown in the Central region of Chiapas and because they are contrasting, they showed differential effects and this condition is necessary in the evaluation of germplasm in the process of genetic improvement (Córdoba, 1991).

Limitations on study/implications: With regard to ear height, the values are acceptable as short plants favor ear rot in hot climates, when there is excess weeds before harvest. The flowering of the genotypes is considered acceptable and they were earlier (55 days) in the Suchiapa site, probably due to the high temperatures of this locality and, in addition, there was the presence of intra-festival drought, compared to the other two experimental sites. The asynchrony between male and female flowering in all genotypes was not significant.

Findings/conclusions: Among the genotypes, there were significant differences for grain yield, plant height, ear height, ear length, and 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 high yields were presented in the environment of Francisco Villa, Villaflores, of the Frailesca region, Chiapas.