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The preservation of native maize allows the selection of genotypes with forage potential in specific regions. The objective of the present study was to evaluate the yield and chemical composition of green forage and silage of 10 native and two commercial maize hybrids with forage potential, under semi-arid conditions with irrigation. Genotypes were grouped according to days to male flowering: early (80 days), intermediate (92 days) and late (111 days). Data were analyzed in a randomized complete block design with four replications (Tukey; a = 0.05). Intermediate and late maize had the greatest height, total dry matter yield (TDMY) and number of leaves (p < 0.05). Late genotypes showed higher values in cob yield and senescent matter (p < 0.05). The genotypes Olotillo × Tuxpeño and Tuxpeño II outperformed the hybrids 2038DK and P3966WP (3.50 and 9.24 Mg ha-1, respectively) in TDMY (14.32 Mg ha-1, on average). Olotillo × Tuxpeño and P3966WP presented similar crude protein values in green forage (81 g kg-1; p > 0.05). However, when ensiled, the hybrid outperformed native corn by 22 % (92 vs. 75 g kg-1; p < 0.05). Late-cycle native maize had the highest cob yields (4.59 Mg ha-1) and after ensiling, the ideal pH (< 3.9) and °Brix (8.5) values. The native genotypes Tuxpeño I, Olotillo × Ratón, Olotillo × Tuxpeño and Tuxpeño II could be used in breeding programs to select materials with potential for forage production and conservation. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In Mexico, about half of white corn production is used for human consumption. In a breeding program, in addition to increasing the yield and genotypes stability, the aim is to improve grain quality. Assuming that there is genetic variation among the elite genotypes evaluated in this research, at least one genotype was considered to be outstanding for its high productive potential and desirable characteristics for grain quality. The objective of this work was to determine the genetic variation present in experimental hybrids in terms of yield potential and grain quality, as well as to identify the most outstanding genotypes. In 2016, twenty white corn experimental crosses were evaluated under a randomized block design with three replications in two locations of the ecological area of the High Valleys of Mexico and one location in a transitional area. Yield stability was determined using the additive main effects and multiplicative interaction model. Grain quality was evaluated through starch, protein and oil content. Most of the crosses had higher yield and stability than the controls (commercial hybrids). Likewise, nutrient content varied among them for each biochemical compound; oil concentration ranged from 3.5 to 6.4 g 100 g-1 dry matter (ms); protein, from 5.5 to 9.8 g 100 g-1 ms; and starch, from 72.6 to 96.6 g 100 g-1 ms. Based on their phenotypic stability, yield and grain quality, we observed that crosses 1213, 1217, 1218, 1314, 1418, and 1812 were outstanding, which can be used to produce grain with promising starch and oil content. In general, we infer that the crosses showed potential for starch utilization and tortilla production. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Environmental factors and their variation affect growth, development and yield of maize (Zea mays L.) in high valleys such as the Valley of Toluca, Mexico. The objective of this study was to evaluate the effect of temperature, precipitation and radiation on the 2008, 2009, and 2010 crop cycles on the yield of six maize cultivars. The hypothesis was that temperature, precipitation and solar radiation in the Valley of Toluca will positively and significantly affect maize yield. The study was conducted in the Facultad de Ciencias Agrícolas of the Universidad Autónoma del Estado de México, Campus El Cerrillo, Piedras Blancas (UAEMex). The data of the climate normals under study were obtained from the meteorological station of the Facultad de Ciencias Agrícolas, Comisión Nacional del Agua, Calixtlahuaca Station, and the Centro de Investigación en Ciencias Agrícolas (UAEMex). These data were analyzed with ANOVA (p=0.05), and the experimental design was completely randomized. Treatments were the years and three data of each variable were the replications. Results indicated that there were significant differences in precipitation, but differences in temperature and radiation were not significant. The highest precipitation (941.3 mm) occurred in 2008 and statistically surpassed that of 2009 (750 mm) and 2010 (579.3 mm). Rainfall was reduced in 2009 and 2010 by a 20.3 and a 38.4% decrease, compared to 2008. The greatest maize yield (1132.6 g m-2) was obtained in 2008 because greater availability of rainfall within the crop cycle coincided with grain fill; this was an effect of synchronization with the R3 and R6 phenological stages. Thus, we concluded that heterogeneity in precipitation limited maize yield, and also the extent of the crop cycle. [ABSTRACT FROM AUTHOR]

Copyright of Ingeniería Agrícola y Biosistemas is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Developing synthetic varieties (VS's) using traditional methods is a difficult task. Even using few potential parents, the possible VS's would be too many to form and evaluate. Hybrid parents can be used to find a solution for this problem. In this research, the use of d double crosses (CD's) as parents of a VS (SinCD) was evaluated, instead of using 4d lines (SinL) to generate synthetics. Inbreeding coefficients (CE's) have been derived from SinCD (FSinCD's); however, their accuracy and generality degree have not been established. The hypothesis of this study was that the current FSinCD's are restricted and inaccurate. Because the performance of synthetics is related to their CE, the objective of this study was to derive a general and exact FSinCD. It was assumed that the initial 4d lines were not relatives and that their CE (F) was 0≤F≤1. The sample of each double cross (m plants) was initially visualized as a "large" series of x groups of 16 plants each (16 genotypes of the genotypic array of the respective CD). As a result of the random mating that generates a SinCD, each CD produces: 1) 16x=m selfpollinations; 2) (15)(16)x=15m direct and reciprocal crosses; and 3) 256x(x=1)=m(m=16) crosses between the x groups. The CE's of these three sets are 1/2, (3=4F)/30, and (1=F)/8, respectively, and it was concluded that the exact CE for "large" m is FSinCD=(1=F)/8d. Based on these results, the general and exact FSinCD was derived for any value of m. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Horticultura is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)