Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
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En México se siembran 7.4 millones de hectáreas con maíz, cerca de 80% de esta superficie es de temporal, en el estado de Morelos se siembran aproximadamente 26 000 ha y se emplea predominantemente semilla de maíces nativos. Los objetivos planteados en el presente estudio fueron: evaluar el nivel de variación morfológica entre poblaciones nativas maíz y sus cruzas dialélicas y comparar la similitud morfológica de las poblaciones nativas con la similitud de sus cruzas. El germoplasma se constituyó por siete poblaciones nativas de maíz de diferente origen geográfico, sus 21 cruzas dialélicas y tres testigos. Los 31 genotipos de maíz se evaluaron en tres ambientes del estado de Morelos (Ayala-otoño-invierno 2012-2013, Ayala-primavera-verano 2013 y Tepalcingo- primavera-verano 2013). El diseño experimental en los tres ambientes fue bloques completos al azar con tres repeticiones. Se midieron 13 variables las que se sometieron a análisis de varianza combinado, comparación de medias DMS0.05, a un análisis de componentes principales y de grupos. Se detectó un alto grado de variabilidad genética inter-poblacional y las cruzas mostraron mayor varianza genética y fenotípica que las poblaciones progenitoras. Se identificaron cinco componentes principales, los que explicaron 91.2 y 83% de la variación fenotípica total, para poblaciones y cruzas, respectivamente. El análisis de grupos reveló el alto grado de divergencia genética entre las poblaciones nativas, al ubicar en diferente grupo a cinco de las siete poblaciones nativas, las cruzas RAT × MOR (C47) y CAB × MOR (C17) mostraron la mayor disimilitud fenotípica.

El presente trabajo se realizó en el ciclo primaveraverano de 2013 en cinco localidades del Estado de México para evaluar la estabilidad del rendimiento de 36 cultivares de haba. Se eligió una serie de experimentos en bloques completos al azar con tres repeticiones por localidad. Las diferencias altamente significativas que se observaron entre cultivares, entre localidades y en su interacción (IGA) sugieren que hay suficiente variabilidad genética para iniciar un nuevo programa de mejora vegetal, que los ambientes del centro del Estado de México son heterogéneos y que la IGA significativa dificulta la identificación de cultivares sobresalientes. Estos resultados fueron confirmados al aplicar los modelos AMMI y de Eberhart y Russell modificando la clasificación de estabilidad con la propuesta de Carballo y Márquez. Los mejores ambientes fueron San Nicolás Guadalupe y Barrio de Guadalupe, ubicados en los municipios mexiquenses de San Felipe del Progreso y San Mateo Atenco. El rendimiento de grano en las cinco localidades varió de 0.24 a 6 t ha-1. Aun cuando no hubo cultivares estables, los más sobresalientes fueron los identificados como T2, T4, T5, T6, T7, T26 Y T30 (de 2.05 a 2.61 t ha-1), colectados en los municipios de Acambay, Jocotitlán, Zinacantepec y Metepec; con excepción de T4, que mostró mejor respuesta en buenos ambientes y fue consistente, T12, T23, T28 y T36 respondieron mejor en buenos ambientes pero fueron inconsistentes.

In northern Tamaulipas, Mexico between 30 000 and 100  000 hectares with maize (Zea mays L.) are grown each year.  The surface varies due to the incidence of biotic factors  (insect pests, toxigenic fungi) and abiotic factors (high  temperature, soil salinity, drought), as well as the availability  of water for irrigation. For this reason, cultural, genetic,  biological and chemical alternatives for crop management  must be constantly evaluated to maximize yield and grain  quality. In this paper, the agronomic behavior and genotype  x environment interaction of eight maize hybrids planted at  four sowing dates and three years of cultivation based on the  analysis of the interaction of main and additive main effects  (AMMI) and model Genotype, genotype x environment  (GGA) Biplot were evaluated; as well as in sequential trail  analysis (ASS). The AMMI analysis for grain yield indicated  significant differences (p≤ 0.01) between hybrids and test  environments. Main components analysis indicated that  the first two components (CP) contributed 76% of the total  variance (PC1= 20 and PC2= 56%); the GGE biplot analysis  indicated that DK-697 was the hybrid with higher yield and  greater stability. The biplot graphic showed that the vectors were further away from the center for year 2006A, 2006B,  2006C and 2007A (greater interaction and genotyping  ability), while the nearest vectors were 2008B and 2008C  (lower interaction). Among hybrids, the most remote from  the origin (less stable) were H-437 and G-8222; the closest  to the origin and more stable was DK-697. The ASS analysis  detected moderate colinearity for all evaluated characteristics,  with strong effects of the number of healthy cobs (Influence  Value of Variance or FV= -1.41) and cob weight (FV= -1.19).  The variables with the greatest association to grain yield were  cob weight, plant height, plant height/cob ratio and number  of healthy cobs explaining 86% of the variation. 

Sugar cane is one of the main crops in tropical and subtropical areas, which have little climatic variation. However, the Intergovernmental Panel on Climate Change (IPCC) said that agriculture in tropical areas will undergo major changes in the next 100 years as a result of this phenomenon. In the state of Veracruz, Mexico, the average annual rainfall is about 1 500 mm and an annual average temperature of 23 °C. However, in the last 30 years, there have been alterations in the hydrological cycle in the sugarcane areas of the central area of the state of Veracruz (Irrigation District 035 La Antigua), as a result of the phenomenon of climate change, significantly impacting the patterns of Precipitation (Pp), evaporation (Ev) and temperature (T) of the zone. The objective of this paper was to evaluate the estimated real evapotranspiration (ETR) of sugar cane, as a result of the increase in the evaporation rate and temperature, and changes in the precipitation patterns recorded in a period of 30 years (1980-2010); as well as the correspondence between the ETR and sugarcane yields observed during the period in the sugar mill area of La Gloria and El Modelo as a consequence of climate change. The ETR was calculated using the semi-empirical methods Penman-Monteith FAO, Blaney-Criddle, Hargreaves-Samani and the Evaporimeter Tank Type A. A high correlation was found between the Penman-Monteith FAO and Hargreaves-Samani methods (r2= 0.9307). No relationship was found between the ETR and the field yield recorded in the supply area of the referred mills. Finally, it is observed a high correlation between the ETR and the maximum temperature derived from the Penman- Monteith FAO (r2= 0.9445) and Hargreaves-Samani (r2= 0.7773) methods.

Maize (Zea mays L.) is an essential component of the Mexican diet, with an average of 120 kg per capita consumption. The Tuxpeño breed has stood out for its high yield and its wide adaptation so that once adapted to temperate climate it is necessary to evaluate the quality of its grains with the parameters of the processing industries. In this research the effect of the genotype*environment interaction on yield and physical characteristics of the grain of 14th and 19th cycles of Tuxpeño maize adapted by mass visual selection (SMV) in the Valles Altos of Mexico was studied. In the 2013 and 2014 years, the original population ‘C0’ and the cycles ‘C14’ and ‘C19’ of SMV were evaluated, both in its original environment, moist tropics in the State of Veracruz, and in its selection environment, temperate subhumid in the State of Mexico. The evaluated characteristics were: grain yield (REN), flotation index (IF), hectolitric weight (PH), pedicel, pericarp and grain germ. The data were analyzed with the AMMI model (main additive effects and multiplicative interactions). The results indicate that selection for adaptation, crop conditions and the effect of the environment during its development favorably modified the REN and some of the grain quality characteristics of the genotypes. Montecillo 2013-PV and 2014 PV the best yield was recorded (3.5 t ha-1), outstanding ‘C19’ due to its stability, hard endosperm grains (<IF) and higher pH.

El cultivo de la cebolla en México representa gran importancia económica y para el año 2014 se establecieron 48 170 ha, uno de los principales problemas para su producción es la presencia de enfermedades en el suelo. El objetivo del presente trabajo fue evaluar diferentes fungicidas químicos y biológicos para el control de la pudrición rosada y su efecto sobre el rendimiento. La investigación se realizó en el INIFAP en el Campo Experimental Costa de Hermosillo, Sonora, México, durante los años 2010 y 2011. El diseño utilizado fue bloques al azar con tres repeticiones. Los tratamientos aplicados no afectaron estadísticamente el porcentaje de incidencia de pudrición rosada ni la altura de planta; en cambio, tuvieron efecto en la severidad de la enfermedad, peso de bulbo y rendimiento. En 2010 la incidencia varió de 39 a 73% y la severidad del daño entre 10 a 34% y los fungicidas con mayor control fueron metil tiofanato (MT), tiocianometitio benzotiazol (TB) y la combinación de TB + Trichoderma harzianum aunque sin mejorar el rendimiento. En 2011 la incidencia de la enfermedad varió de 22 a 30% y la severidad del daño de 14 a 30%. La aplicación de Trichoderma harzianum solo o en combinación con TB fueron los que alcanzaron mayor peso de bulbo y promovieron un incremento en el rendimiento 16% con respecto al testigo. La aplicación de fungicidas químicos y biológicos es una alternativa a corto plazo para reducir la pudrición rosada en cebolla.

The incorporation of male sterility into protein quality maize  (QPM) genotypes (Zea mays L.), facilitates seed production  and offers a maize grain with better protein quality of  agronomic advantages. Experiments were carried out in  Cuautitlán Izcalli and Santa Lucía de Prías, Texcoco, State  of Mexico, in order to determine the productivity of simple  maize crosses between six androthermal lines and three elite  lines, all of them QPM. 18 single crosses and trilineal hybrids  H 47 AE and TSIRI PUMA of normal quality as controls were  evaluated in a randomized complete block experimental  design with three replicates. The grain yield, days at male  flowering, height of plant and cob, number of rows per cob,  number of grains per row and number of grains per cob were  estimated. The best simple quality protein maize crosses  (QPM) were LAEQ5 CML354, LAEQ4 CML173 and  LAEQ3 CML173 in both localities, with yields greater than  8 t ha-1, exceeding the yield of commercial controls from 43  to 57%. These crosses could participate in the formation of  superior trilineal hybrids when combined with a third line  that generates a good hybrid. Due to their participation in the upper crosses, the best QPM androthermal lines were  LAEQ3, LAEQ4 and LAEQ5, while the best elite QPM  lines were CML 173 and CML 354. 

In order to provide information regarding farmers' preferences for improved and native maize seeds, a semi-structured questionnaire was applied to 210 maize producers from the highest-producing municipalities in the Yucatán Península of which five municipalities were located in Campeche, Two in Yucatán and one in Quintana Roo. The producers were randomly selected and the sample size was calculated with stratified sampling by classifying the producers into two groups or strata according to the planted area. Considering the number of years of use of the seed, the degree of satisfaction of the products obtained, the agronomic advantages of the seed and its availability in the market, an indicator was generated that allowed to classify the producers in three categories according to the adoption level of the seed component. As a result, only 97 farmers in the sample know the seeds generated by INIFAP (H-520 and VS- 536). Of these, 16.7% started the adoption process and interrupted it, 7.1% knew it and adopted it, 12.9 % knew it, but did not adopt it. The native preferred materials of were Tzib-bacal and Tuxpeño for the preparation of tortillas, pozole and atole. Most of the interviewees are mainly engaged in agriculture and their production is marketed locally or in regional markets.

The huitlacoche (Ustilago maydis (DC) Corda) is a good  source of nutrients in the diet. During post-harvest handling,  the product shows a rapid senescence, attributed to the  high rates of dehydration and respiration of the product,  in addition to its composition. In order to prolong shelf  life, the effect of high relative humidity and low storage  temperature on the physical properties of huitlacoche  (whole and in galls) and the presence of phytopathogenic  fungi were evaluated. The results showed that at 3 ºC the  dehydration rate decreased, maintaining the visual quality  for longer, both the whole huitlacoche and in galls. Storage  with high relative humidity at room temperature favored  the proliferation of phytopathogenic host species such as  Fusarium oxysporum, Rhizopus stolonifer and Penicillium  expansum. The highest incidence and severity was shown  by F. oxysporum inoculated with a wound in the gall, while  R. stolonifer, although with a lower incidence than the other  two species, was able to survive up to 10 ºC. The results  demonstrate that the management of huitlacoche at 3 °C  and high relative humidity in ambient air is feasible, as it  counteracts the rate of dehydration and eliminates the risk  of proliferation of host phytopathogenic fungi. 

Small maize producers are unaware of the agronomic  behavior of new genotypes in their work area and the use  of technical irrigation systems. The objective of this paper  was to evaluate the agronomic behavior of hybrid maize  cultivated in fertirrigation. The study was carried out in the  2014 winter-spring cycle in the School of Higher Studies  of Xalostoc. The number of leaves above the cob, total  leaves, cob weight, cob diameter and grain yield were  measured. A completely random block design was used.  The best hybrid for leaves above the cob (6.46), total leaves  (13.66), cob weight (206.88) and grain yield (7 613.3 kg  ha-1) was H-377. It was confirmed that the new introduced  genotypes should be evaluated and technification for water  saving and yield raise is required.