Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

quality variables have been identified with reduced genetic  variability which must be extended for its use through  selection. Therefore, the objective of this paper was to  estimate genetic variability, heritability and correlate quality  variables that favor bread volume and its stability, in US and  Canada wheat, in order to use them as sources of genetic  variability and to favor baking quality in breeding programs.  Sixteen genotypes were planted in eight storm sites. The  hectoliter weight, protein content in flour, sedimentation  volume, the tenacity/extensibility ratio, dough strength and  bread volume were measured. The dough strength showed  the highest coefficient of genetic variation (24.3) and high  heritability (0.37). The protein in flour and sedimentation  volume associated coefficients of variation less than 10 and  acceptable values of heritability, 0.33 and 0.23, respectively.  The volume of bread and hectoliter weight had the lowest  coefficients of genetic variation and heritability, so new  genetic sources should be searched for these characters.  Bread volume correlated positively with protein content,  dough strength and sedimentation volume and inversely with the tenacity/extensibility ratio. The genotypes Nahuatl  F2000, Waldron, Ac Vista, Line 2, Kronstad F2004 and  Kulm showed very good stability and bread volumes greater  than 800 mL desirable characteristics for baking. Based  on the above, genotypes that combine high bread volume  with adequate stability that can be used within the breeding  program were found. 

The objective of this paperwas to study the effect of  yield of Brachiaria humidicola cv Chetumal grass at  different frequencies and intensities of grazing. The cutoff  frequencies of 21 and 28 d and the intensities of 9-11 and  13-15 cm were evaluated, which were randomly distributed  in a random block design with 2*2 factorial arrangement  with three replicates. Management effects on dry matter  accumulation were observed, with accumulation at lower  frequency and light grazing intensity being greater. Forage  production had a seasonal distribution of 66, 26 and 7% in  the rainy season, north and dry seasons, respectively. The  leaf ratio in harvested forage was 20, 30 and 86% for north,  dry and rainy seasons, respectively. Reductions in dry matter  digestibility were observed in the north and rainy seasons  as the cut interval increased. The crude protein with severe  grazing was 11, 10 and 17% higher in the north, dry and rainy  times than with light. It is concluded that the highest forage  production was obtained when harvesting at a light intensity  of 13-15 cm, every 28 d and the highest protein content and  digestibility was obtained when the forage was harvested  at severe intensity every 21 d. 

The litchi (Litchi chinensis Sonn.) in Mexico, has had a  significant increase in plantations in the last two decades,  settled in warm regions in several cases, where there is  a very marked alternation of production. The objective  was to evaluate the flowering and fruiting of litchi, in  orchards with different agroecological conditions and  management, in the central and northern regions of  the state of Veracruz in the 2010 year. Six contrasting  orchards were selected, five with cv. Mauritius and one  with 'Brewster', and in each one maximum and minimum  temperature thermometers were placed. In order to follow  the sprout length, inflorescences, berthing of fruits and  harvested fruits, four sprout were marked per cardinal  point, in 10 trees per orchard. The floral and vegetative  sprouts were counted per m2 of tree top, in the middle  part of the tree. A physical-chemical analysis of the  soil was carried out in each orchard. In order to know  the management, a questionnaire was applied to the  producers. The altitude of the orchards was between 7  and 732 m, minimum temperatures ranged from 13.5 to  18.1 °C, which influenced the flowering response, where  the Tuxpan 71.63% and Yecuatla orchards stood out  with 66.28%. The fruiting and yield presented variation according to the cultivar, temperatures and management  practices; for ‘Mauritius’, the outstanding orchards were  Tuxpan with 7.4 t ha-1 and Yecuatla with 3.6 t ha-1. For  ‘Brewster’ the yield was 4.1 t ha-1, in the Tolome orchard. 

The seeds of Jatropha curcas L., present high oil content,  and therefore have a high potential as a raw material for  biodiesel productio. However, the production level and oil  content in non-toxic seeds from Veracruz is unknown. The  objective of this paper was to determine the oil content and  yield of different accessions of non-toxic J. curcas collected  in different regions of the state of Veracruz, sexually and  asexually propagated, and established in the central region  of Veracruz. The plant material consisted on 16 nontoxic  accesses, propagated by seed and stakes. In three-year-old  plants morpho-productive determinations were made,  and seeds were collected during the 2014 cycle. For the  extraction of oil, the Goldfish® equipment was used, using  hexane as solvent. No statistical differences were found  between accesses for oil content. In general, all accesses  had high values in oil content. In plants propagated by seed  fluctuated between 54.13 to 60.98%, and in those originated  by stake was from 51.75 to 58.48%. Significant positive  correlations were found between fruit number and oil content  (r= 0.74) and seed weight and oil content (r= 0.79) in seed  propagated plants. The highest oil yield per hectare, based  on the number of fruits (157) (184) and seed weight (641.1  g plant-1) (817.8 g plant-1) corresponded to accesses I-32 and I-34, with 590.55 and 761.68 L ha-1, respectively, in seedpropagated  plants. It is concluded that seed propagated plants  had a better performance than those propagated by stake. 

Small and medium-sized companies have to find a way  to keep up competing with large companies, as they have  upgrade their markets leading to the disappearance of many  of them; and integrating companies have emerged with the  purpose of grouping small and medium-sized companies  so through this union they would obtain profitability and  competitiveness advantages. The financial profitability  of pine harvesting of an integrating company located in  Ixtlán de Juárez, Oaxaca, was evaluated using surveys to  gather information and to perform the financial profitability  assessment as an integrating company by calculating  indicators as net present value (NPV), Internal return rate  (IRR), cost benefit ratio. The results obtained were: NPV=  481 952.4, IRR= 33% and cost benefit ratio= 1.01. It was  found that during the useful life of the project at an updating  rate of 31%, a net profit of 481 952.4 Mexican pesos will be  obtained. Regarding to the cost/benefit ratio to an update of  31%, for invested peso there will be 1.01 cents of benefits  and over the project existance and according to the results of  the IRR the investment would be recovered and an average  profitability of 33% would be obtained. These indicators  show that the company has a positive financial return. 

The area destined to produce traditional basic crops  changes to other commercial ones: vegetables and flowers,  contributing to the creation of income and jobs. Its  installation, requires greenhouses to avoid flowers damage,  deforesting forests; using agrochemicals; causing waste  and generating high costs of production. The objective  of this research was to analyze the sustainability of the  flower production system and its importance for the peasant  families of Zinacantán, Chiapas. The field work was carried  out in the agricultural cycle: winter-spring-summer (2015-  2016) in the municipality of Zinacantán. A methodology  with mixed approach (qualitative and quantitative); the  qualitative one with social research techniques; and  quantitative one using a questionnaire that was applied  to flower producers (81), using the framework for the  evaluation of natural resources management incorporating  sustainability analysis (MESMIS). Results obtained  indicate that of the indicators proposed for sustainable  evaluation (17), indicators (11) have an index greater than  50% help to strengthen the system and six of them weaken  it. Production is not sustainable due to deterioration and  contamination of natural resources; peasants interviewed know the problems caused by the production of natural  resources; and there are very few activities they do in order  to take care of it. It is concluded that flower production is a  non-sustainable production and it is important for peasant  families because it generates income. 

The vegetative propagation of nanche (Malpighia mexicana  A. Juss. and Byrsonima crassifolia (L) H.B.K.) was  evaluated, under shade at 70 and 90%, and Indole butyric  acid (IBA) at 1 000, 3 000 and 10 000 ppm and a control.  The stem cuttings were collected in Oaxaca, Mexico, and the  experiment was established at the Colegio de Postgraduados,  Montecillo Campus. 240 stem cuttings of 20 cm of each  species were impregnated 5 cm from the base with IBA  treatment and seeded at 10 cm depth in 5 L trays filled with  peat with sand (1:1 v/v); these combinations resulted in  16 treatments, each with 3 replicates of 10 stem cuttings  (experimental units) that were established in a BCA design.  At 7 months the percentage of survival, sprouting, cuttings  with callus and rooting, and number and length of roots were  evaluated. The ANOVA and the Duncan test of means (p≤  0.05), indicated that the two species showed survival and  sprouting, but only M. mexicana showed roots; shadow at  70% was better and in these variables, the control overcame  the other treatments; however, only the cuttings treated with  IBA showed roots. B. crassifolia produced callus in the  stakes when 10 000 ppm IBA was used. 

Jasmonic acid (JA) is an endogenous phytohormone that  regulates plants growth. This is found in many plant species  and is involved in various functions including resistance  and senescence, is produced by the plant after damage  caused by a pathogen, which can be a microorganism or  an insect, resulting in an increase in the production of  resistance compounds. The natural resistance of plants to  pathogens is based on the combined effects of preformed  barriers and inducible mechanisms. A complex network  of hormone signals has been shown to control the plant’s  response to pathogen attack. Depending on the type of  inducing agent, there are two types of resistance induction:  biotic and abiotic, each activated depending on the damage  type. 

The objective of this paper was to study the efficiency  of rootstock use on yield and nutritional dynamics of  macronutrients in bell pepper. Fascinato and Janette  commercial varieties of bell pepper were used and a  commercial Terrano rootstock. The experiment was  carried out in a shade mesh system in Delicias, Chihuahua,  Mexico during the production cycle of 2012. The results  indicate that the variety-rootstock Fascinato-Terrano  and Janette-Terrano produced the highest fruit yields,  53.47% and 49.40%, respectively, in relation to the same  ungrafted varieties. Also, Fascinato grafted with Terrano,  showed the best nutritional status that contributed to the  maximum yield, assuming that the use of rootstocks could  be a viable technique in the sustainable horticulture of  the future. 

Se determinaron las características bioquímicas, fitoquímicas y antioxidantes de las nuevas variedades de jamaica Hibiscus sabdariffa: Alma Blanca (VAB), Cotzaltzin (VC), Rosalíz (VR) y Tecoanapa (VT), comparadas con la variedad Sudán (VS), para impulsar el uso alimenticio y nutricional de los cálices de la flor. Se realizó el análisis proximal de los cálices de las flores de las variedades de jamaica, así como los contenidos de aminoácidos, compuestos fenólicos y ácidos fenólicos. Mostraron diferencias estadísticas entre las variedades y para los contenidos de proteína, carbohidratos, lípidos, cenizas y fibra, así como los aminoácidos, fenoles totales y ácidos fenólicos, para las cinco variedades. Los lípidos varían de 17.7 a 22.8% y son mayores en VT y VS; las proteínas son altas en VT (5.8%) y VS (6%); de fibra contienen más VAB (43.9%) y Rosalíz (40.1%) y cenizas en VAB (9%) y VC (8.3%); en carbohidratos es mayor para la VC (37.5%). Se encontraron seis aminoácidos esenciales, la isoleucina y treonina pasan los requerimientos mínimos necesarios para los niños de la infancia y de preescolar y los adultos en todas las variedades; la VT presentan más lisina y las VAB, VC, VR y VS contienen más metionina + cisteína. Las variedades VAB, VC, VR y VT mostraron aproximadamente 50% de fenoles totales en comparación con VS; la VAB presentó menor contenido de taninos (65.5 mgEC/100 g); la VS es más alta en antocianinas. El ácido vanillico es abundante en las VR y VT y el ácido 4-hidroxibenzoico en VC; los ácidos salicílico y clorogénico son altos en la VAB; mientras que, el ácido protocatecuico es alto en las VR y VT, considerado con propiedades anticancerígenas. Las nuevas variedades de jamaica representan una alternativa para el consumo humano, por las características bioquímicas y nutracéuticas.