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

The density of plants or stems is a variable of agronomic management associated with the productivity of vegetables under protected conditions. The research was carried out with the objective of knowing the influence of plant density and stem pruning on plant growth and yield of cucumber fruits grown under greenhouse conditions. The design of complete blocks was used randomly in factorial arrangement, with two levels each factor: plant density (1.68 and 2.22 plants m-2) and stem pruning (one and two stems plant-1). The treatments: T1) 1.68 plants m-2 with pruning to a stem plant-1, T2) 1.68 plants m-2 with pruning to two stems plant-1, T3) 2.22 plants m-2 with pruning to a stem plant-1 and T4) 2.22 plants m-2 with pruning to two stems plant-2, were established with four repetitions. The results indicated that fresh biomass of plant stem and dry leaves plant-1 decreased with increasing plant density, but increased in plants with pruning to two stems plant-1. Stem length, dry stem biomass, plant leaves, fresh leaf plant-1 biomass and flower plant-1 production also increased with two stems plant-1, while leaf greenery decreased, but no influence on those variables by density of plants. Both factors caused a decrease in the diameter of the fruit. However, the best cucumber yields: total (112.8 t ha-1), select (22.4 t ha-1) and super select (53.6 t ha-1), were positively influenced by plant density as well as by pruning of stems.    

  The present essay aims to investigate the state of the art in the matter of the fungus Ug99 considered by international organizations as one of the main threats to world food security. To this end, the importance of wheat supply and demand at an international level is estimated and the damage that could be caused by an outbreak of the fungus Ug99 is estimated. Likewise, the origins, evolution, geographic dispersion and classification of stem rust are analyzed to differentiate their types, breeds and danger of infection of the different genes contained in wheat. In this context, the most recent evidences of its presence and the strategies for its control and combat are documented. Finally, it is concluded that even Mexico is vulnerable in case of an epidemiological outbreak in North America caused by Ug99, both on the production and consumption side.

Cocoa is a product originating in Mexico whose production does not meet domestic demand, so there is a need to import much of what the Mexican market consumes, therefore, it is of great importance to distribute optimally the quantities produced internally with the purpose of minimizing the transportation costs of the grain. The objective of the research was to formulate a transport model that optimizes the distribution of cocoa in Mexico, minimizing the cost of transportation, both for a closed economy and for an open economy. Linear programming was used to solve the transport problem, since it allows determining the optimal way to transfer goods, minimizing total distribution costs. The main results show that the national apparent consumption, in 2015, was 51 394.13 t, the apparent per capita consumption of cocoa in the country was 0.43 kg. The states that can see totally satisfied their demand for cocoa, only with the surplus of state production of Tabasco and Chiapas, are: Guerrero, Oaxaca, Querétaro, Quintana Roo, Tamaulipas, Veracruz, Campeche, Mexico City, Hidalgo, State of Mexico, Morelos, Puebla, Tlaxcala and Yucatán, while Michoacán can obtain 14 of the 65 trucks it demands. The above, leads to a minimization of transportation costs, this being $9 500 068.00. In order to meet the national demand for cocoa, two ports of entry for this crop were considered and the minimum transportation cost was $18 123 640.00.

The physicochemical characteristics of potato tubers have been reduced due to the presence of Zebra chip (ZC). The use of anti-aphid nets is becoming a popular approach to provide physical protection from insects that transmit ZC. The aim of this work was to evaluate the physicochemical characteristics of potato tubers and their chips, produced with and without the protection of an anti-aphid net in Metepec State of Mexico. Five genotypes were studied (Fianna, Nau, 5-10, 8-65, 99-39). The anti-aphid net reduced 34.5 % the photosynthetic active radiation and consequently the starch accumulation and chips yield. ZC infected the non-covered plants and their tubers had more browning and reducing sugars (19.67 g kg-1) than covered tubers (4.77 g kg-1), but they had similar contents of total phenolic compounds. Potato crop protection with an anti-aphid net may be an alternative to produce tubers with quality for fresh consumption and chip processing.

In the last three decades the consumption of meats in Mexico has changed due to the variations in their prices and the income of the population. The present investigation analyzes the relationship between the income of the population and the demand for meats in Mexico from 1980 to 2016. The analysis of the demand was made from elasticities calculated by means of the almost ideal demand system model (AIDS). The results indicate that the consumption of chicken and sheep meat responds in greater proportion to the changes in the income of the population. Chicken meat has responded better to market changes, while the beef and pork industry faces international competition and the national poultry industry. It is concluded that the development of the meat industry in Mexico is subject to an improvement in the purchasing power of the population, in which case, the most benefited industry is chicken.

The monitoring and prediction of prices is an important tool in decision making in productive activities. Based on the monthly average price data of the red delicious apple at a national level, from January 1998 to July 2017, published by the national system of information and market integration, with the Gretlâ software. The objective of the research was to generate information on the price behavior of the apple by means of a time series analysis, generating a prediction for the following 12 months with a Sarima model . The results indicated that the relative error for the prediction is 2%, which guarantees relatively good forecasts, it was predicted that the price for July 2018 would be $31.99.

Ante el incremento de la presencia humana y sus actividades productivas en áreas naturales protegidas, se planteó el objetivo de caracterizar el sistema de producción ovina, en el Nevado de Toluca, con información agrícola, socioeconómica y uso de los recursos de pastoreo. Un total de 162 productores fueron entrevistados, se analizaron 25 variables con estadística multivariada y univariada. Mediante análisis de componentes principales se obtuvieron seis factores que explican el 71 % de la varianza. El análisis cluster permitió identificar tres grupos de productores: pequeños (28 %), intermedios (35 %) y capitalizados (6 %), diferenciados por el número de animales, superficie cultivada e ingresos (P<0.05). En el sistema de producción, se observó alta mortalidad de corderos (23 %), la siembra de avena (Avena sativa) en el 50 % de la superficie y un porcentaje variable de superficie, sembrada de maíz (Zea mays). La edad y escolaridad fueron similares entre grupos (P>0.05) y se encontró que los rebaños aportan menos del 30 % del ingreso familiar. El 58 % de los rebaños ingresa al bosque, para realizar pastoreo circulante, pero el 60 % se maneja semi-estabulado. Se concluye que la producción del sistema no depende de la capitalización del productor, pero el rebaño es esencial en la economía familiar, y el manejo de los animales es compatible con los esfuerzos de conservación del área natural protegida.

The intestinal parasite Cryptosporidium spp. is highly infectious in wild and domestic animals and humans. Infection frequency in dogs can vary between rural and urban environments. Cryptosporidium spp. infection frequency was quantified in dogs on dairy farms and in an urban area in the state of Aguascalientes, Mexico, and some possible risk factors analyzed. Feces samples were collected from 168 dogs at 30 dairy farms distributed among the state’s ten municipalities (rural), and from 144 dogs at the Aguascalientes municipal Animal Control, Care and Welfare Center (urban area). Fecal smears were stained with Kinyoun to identify and count parasite oocysts. A questionnaire was applied to gather information on factors that could increase infection risk, and a risk analysis run using logistic regression. Overall infection frequency was 20.5 % (64/312; CI95% 16-25). In farm dogs it was 30 % (51/168; 95% CI 23-38) and in urban dogs 9 % (13/144; 95% CI 5-15). Seventy percent (70 %) of the dairy farms had positive dogs, average number of dogs per farm was 5.6, and dog density per farm was 2 to 12. Diarrheic feces was the only identified risk factor for Cryptosporidium infection, in both urban dogs (OR, 3.2; 95% CI 1.06-9.79 P<0.03) and farm dogs (OR, 2.7; CI95% 1.36-5.49 P<0.001). Infection frequency was highest in farm dogs, suggesting a consequently higher probability of cross-infection in this type of environment.

Use of natural source additives in animal production is increasingly important because they potentially promote growth in ways similar to synthetic compounds, such as anabolic hormones and antibiotics, but without risks to animal or consumer health or degrading meat quality. Encompassing a wide variety of compounds extracted from different plant parts, natural origin additives can be administered as essential oils, mixtures of compounds or isolated compounds to function as medicinal remedies or dietary supplements. Phenolic compounds are widely used and include hydroxycinnamic acids, present in a variety of vegetables, fruits and grains. These acids exhibit interesting bioactivities such as antioxidant, antimicrobial, prevention of cardiovascular diseases and immunomodulation. Use of hydroxycinnamic acids in animal production is currently limited but may hold promise in promoting growth. Before this can occur further research is needed on their pharmacokinetics and pharmacodynamics, posology, exposition period and effects, as well as their possible metabolic routes and biotransformation in animal organisms. This review covers inclusion of hydroxycinnamic acids in livestock diets, their pharmacokinetic properties and pharmacodynamics, and findings on their effects in promoting growth and improving meat quality.

The demand for meat from animals raised with the minimum use of antibiotics is growing. Also, the use of prebiotics, antibiotics, type of cut of meat to modify the fatty acid profile and the effects on consumer preferences are still not clear. The present study investigated the fatty acid profile, the health, and risk fatty acid indices and the consumer sensory evaluation of rabbit’s meat fed inulin and flavomycin as additives. Forty-eight New Zealand rabbits were randomly arranged into 4 treatments of 12 animals each. The control group did not receive antibiotic or inulin supplementation. The second group was supplemented with inulin while the third group received flavomycin as supplement. The fourth group received both inulin and flavomycin. Inulin addition in rabbit’s diet increases beneficial fatty acids (CLA and n3-PUFA) and enables a better health-promoting index while reducing the atherogenic and thrombogenic indices of meat. The type of cut of meat (loin, fore legs and hind legs) had a minor impact on changing the fatty acid profile. In contrast, inulin or flavomycin addition showed larger modifications than type of cut of meat on this respect. Flavomycin reduced hedonic properties of meat. Loin tended to be the most preferred cut of meat. Inulin is a good alternative to avoid the utilization of antibiotics in rabbit’s feeding.