ABSTRACT The objective of this work was to evaluate the agronomic performance of a second crop maize grown under different methods of inoculation with Azospirillum brasilense. The experiment was conducted in a randomized block design with 6 treatments and four replications. The treatments used were: no inoculation (T1); inoculation with A. brasilense via seed (T2); inoculation with A. brasilense via sowing furrow (T3); inoculation with A. brasilense via leaf (T4); two inoculations with A. brasilense via leaf (T5); and combination of inoculations via seed, sowing furrow, and leaf (T6). Physiological, morphological, production, and yield components of the second crop maize were evaluated. The data were subjected to analysis of variance at 0.05 probability level and when significant, the means were subjected to the Scott-Knott test at 0.05 probability level, using the R-bio statistical program. Inoculation via seed results in higher nitrate reductase enzyme activity. The inoculation with A. brasilense does not result in gains in grain yield for second crop maize; however, it improves the maize quality by increasing its gross protein contents.

Abstract The present study selected progenies, aiming at the production of green corn, by methods of intrapopulation recurrent selection with subsequent recombination, generating open-pollinated populations. To this end, in the 2017/2018 second season, progenies from the PMVJ01 population (originated from the recombination of progenies of the TG-02R2 x AG1051 cross) were evaluated, using PMVJ01 and the hybrid AG1051 as controls. The following parameters were evaluated: flowering, heights, green ear yield, husk cover, ear diameter and length, mass yield, ear shape, number of rows on the ear, alignment of rows, color of kernels, and husk width and length. Genetic parameters were estimated, and the gain was predicted with the selection of 20% of the progenies, using the index of Mulamba and Mock in four selection procedures and a fifth by multivariate method. Genetic variability was found in the population, which allows advances in the selection process. After recombination, two of the populations generated showed potential for use as open-pollinated cultivar.

Resumo: O objetivo deste trabalho foi determinar a estratégia seletiva mais adequada para o incremento simultâneo de componentes da produção de milho verde, pela comparação de três índices de seleção, ponderados por pesos econômicos, e pelo método REML/BLUP, na avaliação de ganhos genéticos previstos para os caracteres de interesse. Um ensaio com 75 híbridos topcross, de linhagens S1 parcialmente endogâmicas de milho-verde foi implementado em Jataí, GO, Brasil, tendo-se utilizado um delineamento de blocos ao acaso, com quatro repetições. As seguintes características de produtividade foram avaliadas: espigas empalhadas e espigas comerciais, massa de grãos, comprimento de espiga, diâmetro de espiga e número de fileiras da espiga. Os índices de seleção de Smith e Hazel, Williams e de Mulamba & Mock foram aplicados e ponderados por quatro pesos econômicos (1, CVg, CVg/CVe e h2). Entre os índices de seleção testados, o de Williams e os de Mulamba & Mock são os melhores para a seleção de híbridos de milho verde, pois proporcionam ganhos de seleção positivos e mais equilibrados em todos os caracteres avaliados. O método REML/BLUP apresenta melhores ganhos genéticos preditos do que os obtidos pelos três índices de seleção estudados, além de ser eficiente para a seleção de híbridos topcross de milho verde.

Abstract: The objective of this work was to define the most suitable selective strategy for the simultaneous increment of yield components of green maize, by comparing three selection indexes weighted by economic weights and by the REML/BLUP method, in the assessment of predicted genetic gains for traits of interest. An experiment with 75 topcross hybrids from partially inbred S1 lines of green maize was carried out in Jataí, in the state of Goiás, Brazil, using a randomized complete block design, with four replicates. The following yield traits were evaluated: straw ears and commercial ears, grain mass, ear length, ear diameter, and number of ear rows. The selection indexes of Smith and Hazel, Williams, and Mulamba & Mock were applied and weighted for four economic weights (1, CVg, CVg/CVe, and h2). Among the tested selection indexes, those of Williams and Mulamba & Mock are the best-fit ones for the selection of topcross hybrids of green maize, as they provide positive and more balanced selection gains for all evaluated traits. The REML/BLUP method shows better predicted genetic gains than those achieved by the three selection indexes, besides being efficient for the selection of topcross hybrids of green maize.