Multienvironment testing is an important phase to study the interaction of G × E and to select stable hybrids for a broad environment or for a specific environment. To study the interaction of G × E and the stability of earliness and yield of Indonesian new sweet corn hybrids under different locations and seasons in West Java, Indonesia, eighteen hybrids were evaluated in six environments in West Java, Indonesia, and were analysed using parametric and nonparametric stability models, additive main effects and multiplicative interaction (AMMI), and GGE biplots. Results showed that the most promising sweet corn hybrids including hybrids G5 (SR 24 x SR 17) and G11 (SR 31 x SR 17) were identified. The parametric and nonparametric stability parameters and ASV were complement to the AMMI and GGE biplots in selecting stable and adaptable hybrids in terms of earliness and yield. G5 was selected as a high-response hybrid for grain yield to Jatinangor (E1, E2), Lembang (E3, E4), and Wanayasa (E5, E6), as well as earliness to Jatinangor (E2), Lembang (E3, E4), and Wanayasa (E5, E6). G5 sweet corn hybrid, therefore, is suggested to be extensively evaluated on farm and produced for smallholder farmers in West Java, Indonesia.

Hybrids that are stable or adaptable in a specific location for the western region of Indonesia are required to increase production of maize in Indonesia. The objectives of the study were (i) to select maize hybrids which are stable or adaptable in the western region of Indonesia and (ii) to determine the discriminant location for evaluating superior hybrids in the western region. Therefore, twelve maize hybrids were planted in different locations and seasons in the western region. Hybrids were selected based on GGE biplot analysis. The results showed that G9 and G10 were stable maize hybrids. G6 was the selected hybrid for the first megaenvironment; whereas, G3 was selected as the hybrid for the second megaenvironment. The L8 and L17 were the discriminant environment for evaluating hybrids in the western region of Indonesia. The high-yielding hybrids selected in this study should be broadly evaluated on-farm in order to disseminate for small holder farmers in Sumatera and Java islands.

Selection of high yielding and stable maize hybrid requires effective method of evaluation. Multienvironment evaluation is a critical step in plant breeding programs that is aimed at selecting the ideal genotype in a wide range of environments. A method of evaluation that combines a variety parameter of stability could provide more accurate information to select the ideal genotype. The aims of the study were (i) to identify the effect of genotype, environment, and genotype × environment interactions (GEIs) on maize hybrid yields and (ii) to select and to compare maize hybrids that have high and stable yields in diverse environments in Sumatra Island based on combined analysis, selection index, and GGE biplot. The study was conducted in five different environments in Sumatra Island, Indonesia, using a randomized complete block design repeated three times. Data were estimated using combined variance analysis, parametric and nonparametric stability, sustainability index, and GGE biplot. The results showed that the genotype had a significant effect on maize hybrid yields with a contribution of 41.797%. The environment contributed to 24.314%, and GEIs contributed 33.889% of the total variation. E1 (Karo, South Sumatra; dry season) and E3 (Tanjung Bintang, Lampung; dry season) were identified as the most ideal environments (representative) for testing the hybrids for wider adaptability. The maize hybrid with high and stable yields can be selected based on combined stability analysis and sustainability index as well as GGE biplot. These three methods are effectively selected high yielding and stable genotypes when they are used together. The three maize hybrids, namely, MH2, MH8, and MH9, are recommended as high yielding and stable genotype candidates.

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Maize is one of the most important cereals in the world after wheat and rice. Now-a-days, the improvement of maize production is hindered by conversion of agricultural lands into industrial and residential areas. One of the suggested solutions is the production of maize cultivars that can be incorporated in agroforestry systems and can be grown with tree plants such as Albizia. The success of the improvement of new maize cultivars suited to this Maize-Albizia system depends on the availability of genetic variability. Research on the genetic diversity of maize inbred lines that is suited to the agroforestry system with Albizia were conducted in a real forests planted with Albizia tree plants that are around three years old in Cimalaka, Sumedang, West Java, Indonesia. The evaluation of inbred lines was laid on a split plot design with two replications. The main plot consisted of two cropping systems, namely; maize sole cropping system and Maize-Albizia agroforestry system. The subplots were having seventy five inbred lines of maize. The biometric characters included days to anthesis, days to silking, days to harvesting, plant height, length of nodes, plant diameter, chlorophyll content, leaf area index, ear length, ear diameter, number of rows, weight of 1000 seeds and ear weight per plant. Based on the analysis of the main components, in conditions maize sole cropping system, the results showed an Eigen value between 1.08-4.52 which contributes to 67.27% variability, whereas, in the condition Maize-Albizia cropping system, the Eigen value ranged from 1.16-5.37 which contributed to 71.85% variability. Cluster analysis of 75 maize genotypes showed a wide distribution obtaining nine clusters in the maize sole cropping system and five clusters in the Maize-Albizia cropping system. High genetic variability seen in both cropping system greatly supports the development of elite new cultivars of maize that can be utilized in agroforestry systems.