Estimación del consumo de forraje para dos biotipos bovinos lecheros en el trópico altoandino de Nariño, Colombia: Consumo materia seca bovinos

The implementation of efficient grazing technologies in high mountain cattle ranches in the department of Nariño (Colombia) increases the sustainability of these production systems and promotes the conservation of the landscape design. With the objective of evaluating the dry matter intake of F1 (Kiwi-cross x Holstein) and Holstein cattle biotypes, present in hillside areas of the Nariño mountain, a preliminary trial of individual consumption of ryegrass (Lolium perenne) was carried out in Pasto (Nariño-Colombia) with the gauging technique, and the results were compared with models reported in the literature. The data were analyzed as a completely randomized design, with repeated measures over time. Intake per gauging was higher (p<0.05) in Holstein cows, with respect to F1 cows (12.74 vs. 9.69 kg/dry-matter/day), but per unit live weight was similar (p>0.05). On the other hand, the milk composition of F1 cows was superior (p<0.05) for fat, protein, and total solids (%). In conclusion, the two breeds evaluated recorded the same forage intake capacity as a function of live weight, but, due to the larger size of the Holstein cows the absolute intake was higher, indicating that an adjustment in forage supply should be made according to the size of the animals. This work contributes to improve grazing techniques, making the use of pastures and their environment more sustainable, which favors productive efficiency and improves the quality of life for the producer families in the area.

Efecto de la duración de cópula en la respuesta ovulatoria y tasa de preñez en alpacas

An experiment was carried out at the Experimental Center La Raya-Universidad Nacional del Altiplano Puno, to determine the effect of copulation duration on ovulation and pregnancy in alpacas. 47 adult females were used (postpartum time ≥ 20 days and presence of a follicle ≥ 7 mm) distributed in three groups, according to copulation time: 20, 35 and 50 min, for G1 (n = 15), G2 (n = 16) and G3 (n = 16), respectively. For the mating, 6 reproducers of proven fertility were used, interrupting the copulation at the established time. Ovulation and pregnancy rates were evaluated on days 7 and 30 post service respectively (by ultrasound and receptivity of the female), the data were analyzed using X2 and simple correspondence. Both the ovulation rate (G1: 73.33%, G2: 81.25% and G3: 81.25%); and pregnancy (G1: 53.33%, G2: 81.25% and G3: 75%) were not different (P> 0.05). Pregnancy rates between G1 and G2 tended to be different (P <0.10), consistent with the simple correspondence analysis. Despite there being no differences in ovulation and pregnancy rates, there was a higher percentage trend in G2 and G3, suggesting that the longer duration of mating would have some positive effect on them, according to the simple correspondence analysis, and the trend of low significance (P <0.10) in favor of pregnancy in G2 compared to G1. In conclusion, there were no significant differences in the effect of copulation duration on ovulation; however, there was a 90% trend for the difference between mating duration of 35 minutes versus 20 minutes (in pregnancy).

Impacto económico del cambio climático en cultivo de quinua (chenopodium quinoa willd) orgánica en la Región del Altiplano: un enfoque Ricardiano

The climate crisis is affecting the production yield of rice, wheat, corn, coffee, beans and other food crops in the country and internationally. The objective of the research was to quantify the impact of climate change on the net income of organic quinoa producers under dry farming conditions in the Altiplano region. Using the Ricardian approach, the impact of climatic variables (temperature and precipitation) on the yield of organic quinoa was estimated in the districts of Cabana, Capachica and Ilave in the Altiplano region, and with primary data collected through a survey to A sample of 237 farmers estimated the value of land productivity. The climatic variables were provided by the National Service of Meteorology and Hydrology of Puno. The results reveal an average production of 1,497 kilos per hectare, obtaining a net income of 14,969 soles per hectare, for a market price of 9.60 soles per kilo. The adaptability of the quinoa producer to climate change was relevant to improve the productivity of the crop. In conclusion, the impact of the agroclimatic variables on the productivity-economic income of organic quinoa producers was marginal in the 2015-2016 agricultural season in the Puno Region.

Respuesta del ñame espino a diferentes densidades de siembra y altura de espalderas

The tubers of spiny yam are one of the main food sources for producers in the Caribbean region of Colombia. However, the productivity of the crop is low due to the scarce use of sustainable management practices that contribute to its improvement. In this sense, a study was conducted at the Turipaná Research Center of Agrosavia, El Carmen de Bolívar, with the objective of evaluating the response in yield of purple stalk hawthorn yam cv. purple stalk to different planting densities and trellis heights. Six treatments were evaluated in a randomized complete block experimental design with a split plot arrangement, the main plot corresponded to two densities (14,285 plants ha-1 and 20,000 plants ha-1) and the subplots to three trellis heights (1.6 m; 2.0 m and 2.4 m). Planting density was the only factor that significantly influenced yield; the use of 20,000 plants ha-1 increased yield by 28.68% compared to the lowest density. The use of supports with heights of 2.4 m in combination with either of the two planting densities induced the production of tubers unsuitable for commercialization. The findings of this research suggest that increasing plant density could be a safe measure to increase yields and economic efficiency in the cultivation of hawthorn yam. Future evaluations are needed on stand height and number of plants to tie per stand.

Mecanismos de inducción de rizobios para reducir el estrés por sequía en las leguminosas

Drought is one of the main limitations of agricultural productivity and food security, in Andean mountain. The use of atmospheric nitrogen-fixing rhizobia in symbiosis with legumes, and tolerant to a wide range of adverse conditions, such as drought, is a great potential in sustainable agriculture. The aim of this review is to compile studies about drought stress effect on the legume-rhizobia symbiosis and rhizobia mechanisms to induce drought tolerance in legumes. The search for information was conducted from August to December 2020, using key terms. The drought effect on the nodulation and atmospheric nitrogen fixation process is made known, as well as the rhizobia ability to synthesize exopolysaccharides, enzymes, phytohormones, siderophores, osmolytes and solubilize phosphates as induction mechanisms to mitigate drought stress in legumes. This review will serve to propose future research using rhizobia to mitigate the drought effect on the legumes cultivation in environments such as the Andean mountains.

Antioxidantes y polifenoles totales de chocolate negro con incorporación de cacao (Theobroma cacao L.) crudo

Cocoa and its main derivative, chocolate, are an important source of antioxidant compounds for human nutrition. Polyphenols are the main antioxidants present in chocolate and are affected by the industrialisation processes of cocoa beans. In this regard, the effect of incorporating raw cocoa during the final stage of the refining process on the antioxidant capacity and phenolic content of dark chocolate was studied. For this purpose, dark chocolates (70%) were made with the incorporation of raw cocoa paste (10, 20 and 30% w/w) in the final refining stage. The antioxidant capacity of all the treatments was determined by the DPPH (2,2-Diphenyl-1-picrylhydrazyl) method and the total phenolic content by the Folin Ciocalteu spectrophotometric method. It was observed that the incorporation of raw cocoa significantly increases the content of antioxidants and total polyphenols in chocolate. As the dose of raw cocoa increases, the antioxidant activity of the chocolate increases linearly (R2=0.996); on the other hand, the polyphenol content increases exponentially (R2=0.968). Only the lowest dose (10%) doubles the phenolic content and the ratio decreases with higher doses of incorporation. The results suggest that the incorporation of raw cocoa in the formulations makes it possible to obtain chocolates with high phenolic content, improving the technological processes for using cocoa produced in the tropical Andes to develop bioactive chocolates, in line with new consumer demand.

Caracterización de fincas hortícolas en Cerro Punta, Chiriquí, Panamá

The objective of this study was to characterize horticultural farms in Cerro Punta, Tierras Altas (Chiriqui, Panama), on socioeconomic and agro-environmental aspects, with emphasis on the pesticides used. Thirty-one farms were randomly selected, and producers were surveyed. In addition, random soil sampling was carried out in five locations for physical-chemical and residue analysis of pesticides such as organophosphates, carbamates, pyrethroids and organochlorines. According to the results, 48% of the respondents were between 41 and 55 years of age, 39% had primary school education and 55% belonged to producer associations. The five main crops are potatoes, carrots, cabbage, lettuce, and onions, and 26% raise animals. Production costs ranged from less than USD 3500 to more than USD 14000 per hectare per year; yields ranged from 3.68 t · ha-1 to 52.62 t ·ha-1, associated with the technologies implemented. Seventy-seven percent of the producers use untreated poultry manure, and 36 different pesticides are used in the area. Fifty-two percent use full personal protective equipment. Laboratory analyses show that the soils are of the Andisol order, with pH between 5.7 and 6.5, organic matter content between 1.34% and 4.34% and effective cation exchange capacity between 8.04 and 26.75.

Presencia de hormonas esteroides en el lago Titicaca y agua potable, Puno (Perú)

The presence of steroid hormones in lake waters causes contamination of aquatic ecosystems, which may cause endocrine alterations in the organisms that inhabit them. Moreover, many of these waters are purified and distributed to populations located around the lake. Therefore, these effects could be repeated in humans consuming the water. This study reports the presence of steroid hormone residues in the waters of the inner bay of Lake Titicaca and drinking water in the city of Puno (Peru). The solid phase extraction method was used for sample preparation, and the analyses were developed in an HPLC-DAD system. Results show maximum concentrations of steroid hormones estrone (E1) 1.56, 17 β- estradiol (E2) 2.27, 17 α- ethinylestradiol (EE2) 13. 88 ng L-1 respectively. These concentrations vary at the different monitoring points, and their presence could cause ecotoxicological effects to the endemic aquatic biota that inhabit this part of the lake. At the same time they also could affect the health of the human population that consumes this water

Censo de aves acuáticas y conservación de humedales en las vertientes altoandinas del Perú

Bird censuses in Peru began in the early twentieth century with seabird censuses carried out by the Compañía Peruana del Guano and later by IMARPE. Between 1992 and 2016 annual censuses were carried out, in 61 wetlands, in 12 departments of Peru, recording a total of 151 species between resident and migratory. The censuses constitute a great contribution to the knowledge of waterbird species and to the synergies between institutions and ornithologists who, through volunteering, compile important information for species conservation and wetland management in the Andean slopes. The taxonomic composition of the species, the importance of censuses, the migration routes of birds from the Nearctic, southern and high Andean regions, and the protected areas in the conservation of wetlands and biodiversity are analyzed. The aim of this paper is to carry out a historical analysis of the censuses and their contribution to the knowledge of waterbirds carried out in the last three decades with special reference to the conservation of wetlands in the Andean slopes in Peru.

Capacidad de infección de hongos asociados a la pudrición seca de los tubérculos de ñame

Dry rot of tubers is one of the most devastating diseases in yam production (Dioscorea rotundata Poir.) in the Caribbean region of Colombia. The disease attacks tubers, causing production losses during cultivation. In previous experiments, 11 fungal morphotypes were isolated and associated with this disease in yam crops in the Caribbean region of Colombia. The present investigation was carried out under greenhouse conditions to determine the infection capacity of these 11 possible causative agents, in 150-day-old plants of two yam genetic materials (0307-49SB y 0307-50CB). The results indicated that morphotypes DH2 (Lasiodiplodia theobromae), DH11 (Curvularia aeria), DH20 (Aspergillus niger), and DH17 (Fusarium equiseti), showed the highest infection capacity to yam tubers, regardless of the genetic material. Therefore, they were considered as the main causal agents of the disease in the Caribbean region of Colombia. The remaining seven (7) morphotypes, despite having been inoculated in the roots of the plants, showed minor effects on tubers and affected other organs of the plant, especially stems and aerial part of yam plant. This study allows concentrating the research on these four morphotypes to develop crop management strategies that might allow reducing the incidence of this disease in the Caribbean region of Colombia.