Biometric analysis in maize genotypes suitable for baby corn production in organic farming system

Abstract

The aim of this study was to estimate and quantify the degree of association between phytotechnical variables for simultaneous selection of maize genotypes suitable to produce baby corn. Seven genotypes were arranged in field in randomized complete block design with four replicates. Genetic parameters, simple, path and canonical correlations of phytotechnical variables were estimated. The variables production of marketable spikes, length of marketable spikes, final plant stand and plant height showed over 80% heritability and variation index higher than the unity, indicating that superior genotypes can be obtained and selection gains. Significant phenotypic and genotypic correlations were observed for production of marketable spikes, positive and of high magnitude with crude protein, dry mass and final plant stand. However, the direct effect between dry mass and production of marketable spikes was pronounced negative (-0.7085), whereas the phenotypic correlation was positive and showed medium magnitude (0.5343), which should be considered the indirect effect of final plant stand (0.7367), to take advantage of the gains of these two traits. The final plant stand is determinant to increase the production of dry matter and marketable spikes, both direct and indirectly. Given the data, we could identify promising variables for plant breeding which can be indicative to select maize genotypes for baby corn production.

Association among Agro-morphological Traits by Correlations and Path in Selection of Maize Genotypes

“…All evaluated traits acted in accordance with the assumption of normality of error distribution (p = .05) by the Lilliefors test and homogeneity of residual variances (p = .05) by the Bartllet test. These results have proved that, normally, the mathematical assumptions needed to conduct the analysis of variance and further studies were satisfied [23].…”

“…The low correlation observed between the insertion height of the first cob and the stripped cob diameter with the grain yield was caused by the negative indirect effects via the stripped cob length, number of rows of grains per cob, plant height, and total number of cobs, with very low values similar to the ones reported by [23]. Conversely, when a direct effect displays positive results, indirect effects are responsible for the lack of correlation [38].…”

“…The direct effect between the variable insertion height of the first cob and yield was negative, (-0.64), while the phenotypic correlation was positive and with a mean magnitude of 0.31, which should take into account the indirect effect in the final plant stand 0.31 to benefit from the gain in these two traits (Table 4). As stated by Nascimento et al [23], the final plant stand is critical to increase the production of dry mass and commercial cobs, both directly and indirectly. This is not the case in Kleinpaul et al [37], who reported a positive value for the trait insertion height of the cobs in the harvest with the yield, even though they had worked with precocious cycle maize cultivars.…”

Canonical interrelationships in morphological characters, yield and nutritional components of corn

“…Alves et al (2016) found a positive phenotypic correlation between phenological and nutritional characters (protein and energy) in corn genotypes. For Nascimento et al (2018), significant correlations between bromatological and agronomic variables show that, the higher the final state of the plant and the greater production of marketable ears, the greater dry mass and the higher crude protein content can be verified, the results show that, by indirect selection, based on the final state of the plant and the production of marketable tips, the authors can select corn genotypes for forage production. High and positive loads of the ear diameter (ED) in the I canonical pair, number of rows per ear (NRG) in the II canonical pair, and negative in the ear length (EL), justified the increase in the levels of total bioactive carotenoids (CAR) for all canonical pairs (Figure 3).…”

“…The morpho-agronomic characters showed a positive and high-magnitude correlation with most bromatological characteristics, such a result showed that the morpho-agronomic traits influenced bromatological features, since they increased simultaneously (Crevelari et al, 2019). Using only path analysis and canonical correlations allow a clearer interpretation of the association between two or groups of variables and the interference that others have in this association (Nascimento et al, 2018). It is important to note that the correlations in corn can be altered by the environmental conditions exposed to the genotypes.…”