Revista de Ciencias Agrícolas

Effect of bypass fat on milk lipid quality and reproductive efficiency of dairy cows

Lesvy Ramos, Jose Edmundo Apraez, Diana Milena David, Jorge Fernando Navia — Fri, 16 Sep 2022 00:00:00 +0000

Nariño (Colombia) has high dairy potential; however, their herds present difficulties in the nutritional component (energy imbalance) of the cows, affecting their productivity. This research evaluated the effect of a bypass fat supplement on lipid concentration in milk and the reproductive efficiency of dairy cows. The study was based on 21 Holstein x Simmental cows between first and third calving and the following was supplied: forage + concentrate (T1); forage + concentrate + 250 g/day of bypass fat (T2) and forage + concentrate + 250 g/day of bypass fat enriched with omega-three (T3). The experiment was conducted from day 15 pre-calving until day 105 of lactation. During this period, milk quantity, quality, composition, and reproductive behavior were recorded. For data analysis, a repeated measure mixed design with time-series data was used, where the fixed effects were the treatments, periods, and their interaction, the animals represented the random effect, and the covariable was the estimated milk yield during lactation. The results showed normal mobilization of adipose tissue; the compositional quality of the milk did not vary across treatments, although T2 presented a higher estimated production per lactation, and T3 presented a higher percentage of fatty acid C18:2. In the reproductive indicators, they were not influenced between the treatments; concluding that the base diet offered in the herd presents a nutritional balance appropriate to the requirements of the cows in production.

Coffee Storage in Hermetic Bags and its Influence on Prices and Sensory Scores

Fri, 16 Sep 2022 00:00:00 +0000

Coffee quality is generally evaluated through cupping, a technique based on sensory perceptions. Trained cuppers assign scores to ten quality attributes on a scale of 1 to 10. Exposure of coffee to moisture and/or oxygen during storage and/or transportation can affect the sensory evaluation and reduce the price received by farmers. This paper has two objectives. First, it estimates the effect of sensory scores and water activity on coffee price and its price differential from the market price. Second, it explores coffee sensory scores sensitivity to storage duration and water activity under two methods of application of the Purdue Improved Crop Storage (PICS) bags - the standard three layers PICS bag (PICS-3L) and the two layers PICS bag (PICS-2L). Data were collected for ten months from an experiment conducted in Manizales, Colombia. Results suggest, on average, that an additional point in the score of flavor or body increases the price of coffee by at least 66 COP/kg (0.015 USD/kg). If coffee has an additional point in aftertaste or uniformity from what is expected from other coffees of the same origin, then its price differential is reduced by at least 8 COP/kg (0.002 USD/kg). Using a PICS-3L bag instead of a PICS-2L bag does not affect the coffee price or sensory scores, but it reduces the price differential by approximately 18 COP/kg (0.004 USD/kg). On the other hand, water activity reduces coffee price but not its price differential. Storage time affects coffee sensory scores in some attributes, which may impact the coffee bean price.

Molecular characterization of Fusarium spp. associated vascular wilt in passion fruit (Passiflora ligularis JUSS)

Claudia Salazar-Gonzalez, Omar Yela-Caicedo, Bladimir Gomez-Espinoza — Wed, 01 Jun 2022 00:00:00 +0000

In Colombia, vascular rotting of passion fruit (P. ligularis) caused by the fungus Fusarium is considered the most important pathological problem in the cultivation of this fruit. Plants affected by the pathogen wilt and die, causing considerable yield losses and increased production costs. The objective of this work was to determine the genetic variability of the Fusarium species associated with this disease. For this, 50 samples were collected from producing farms in three municipalities of the department of Nariño. A total of 35 isolates were characterized morphologically and molecularly. The morphological identification was carried out using taxonomic keys. Molecular characterization was performed by PCR with primers ITS1 – ITS4 and TEF1α. The PCR products were sent to Macrogen (Korea) for sequencing. Sequencing results indicated that Fusarium oxysporum f.sp. passiflorae is associated as a causal agent of the disease. In addition, the presence of Ilyonectria robusta was determined, which, has not been reported before in passion fruit plants. The phylogenetic analysis allowed determine that there was little variability among the isolates evaluated; no grouping was observed associated to the geographical origin of the samples. The morphological characters corroborated the species information obtained from the molecular analysis.

Susceptibility of Amblyomma cajennense (Fabricius, 1787) (Acari: Ixodidae) to calcium polysulfide application

Veronica Soto-Cardona, Santiago García-Cardona, Alberto Soto-Giraldo — Fri, 23 Sep 2022 00:00:00 +0000

Hard ticks are a problem of great importance in the national livestock industry due to their capacity to be vectors of diseases that affect the productivity of animals and humans, becoming an arthropod of veterinary-medical importance. The methods used for their control have not been efficient; therefore, different integrated control alternatives have become crucial to mitigate their population growth. Products such as calcium polysulfide have shown to be an effective alternative in controlling mite populations. The present study was carried out at the Center for Research and Breeding of Natural Enemies of the University of Caldas using nymphs of Amblyomma cajennense, arranged in Petri dishes and sprayed with an average volume of calcium polysulfide of 1.3ml. From there, the lethal concentration of calcium polysulfide at 31.5°B, on the individuals of this species was determined. The evaluations were carried out at 24, 48 and 96h after application, finding, by Probit analysis, Cl₅₀ of 1.05% and Cl₉₅of 1.35% concentration of the product, which indicates that this compound has the potential to be used in the integrated management plan of A. cajennense.

Toxicological studies in poultry consuming fumonisin from corn contaminated with Brazilian Amazonian flora

Fri, 16 Sep 2022 00:00:00 +0000

The fungus Fusarium verticillioides produces fumonisins (FB1 and FB2), characterized by being the most frequently produced molecular forms and with greater toxicity. Fumonisin contamination is responsible for substantial losses during the meat production chain, so the safe levels of these compounds must be determined. The study was directed to establish safe levels of FB1 in poultry production; for this purpose, were used COBB 500^® birds on experimental lots of infected corn during the 2015/2016 season in Brazil. The experimental group included 160 animals, divided into two groups: The T1 without fumonisin in the diet (control); and the T2 group in which corn was contaminated with 2.78 μg/g of fumonisin FB1. Histopathological effects of liver, heart, and small intestine, and zootechnical parameters were measured in birds treated. We found that there were no significant differences between the birds treated and untreated after 21 days of exposure to each treatment; F-values > P-values (P<0,05) for feed intake and weekly weight gain. Taken together, our data showed that the concentration evaluated is safe in poultry and will contribute to the design of future clinical studies.

Cattle movement as a function of some biotic and abiotic factors in a tropical pasture

Thu, 16 Jun 2022 00:00:00 +0000

The research question is how do some biotic and abiotic variables, under a silvopastoral system exert influence on the animal movement? These studies have been carried out through different approaches and have included analyses from empirical to statistical. The aim of this study was to relate cattle grazing sites with some biotic and abiotic factors under a silvopastoral system. The fieldwork was carried out in a paddock of the farm La Reforma located in the upper part of the Magdalena River basin (Tolima, Colombia). Through global positioning devices (GPS), movement, grazing route, and resting data that cattle perform in these habitats during daytime hours were obtained. Six cows (460 kg live weight, not pregnant) were monitored during two periods of the year at one-minute time intervals. Data were processed in a geographic information systems (GIS) environment, and mechanisms and algorithms were used to establish an association of moving animals with some biotic (pasture productivity and cover, trees, and floristic composition) and abiotic factors (climatological season, access to drinking and salt troughs). The results suggest an association between animal movement concerning the different attractants for which the drinking and salt troughs in the paddocks were relevant. In conclusion, the analysis of animal behavior at the landscape level is useful for decision-making in the design of livestock landscapes.

Response of Physalis peruviana L. genotypes to Fusarium oxysporum f. sp. physali under greenhouse

Thu, 16 Jun 2022 00:00:00 +0000

The goldenberry (Physalis peruviana) is an exotic fruit that in recent years has acquired great importance in both the local and international markets; one of the limiting phytosanitary problems for this crop is vascular wilt caused by Fusarium oxysporum f. sp. physali, which causes losses of 80-90%. The management of this pathogen is difficult and so far, it is based on preventive measures; however, there are alternatives such as genetic resistance, which is one of the most effective and profitable measures for its management. Taking that into account, the objective of this study was to evaluate the reaction of 40 genotypes of goldenberry against F. oxysporum under greenhouse conditions, by means of pathogenicity tests. The experiment was conducted in a selected place in the city of Pasto (Nariño department, south of Colombia). It was carried out with 40 genetic materials corresponding to different genotypes, one commercial control and four replicates per experimental unit; the statistical design was completely randomized. The traits evaluated were plant height (cm), disease severity (%), AUDPC area under the disease progress curve (units), disease incidence (%) and degree of vascular discoloration. The genotypes 09U138 and 12U399 have greater plant height (50.19 and 47.36 cm), lower AUDPC (zero units), lower incidence (0%) and lower degree of vascular discoloration (zero), with statistical differences from the rest of the genotypes, including the control. Field evaluations should be conducted with the same isolation and other commercial controls, as this research is only a step forward in the search for the resistance of uchuva to F. oxysporum.

Socioeconomic analysis of cocoa (Theobroma cacao L) agroforest in a tropical dry forest

Jesús-Geovanny Solarte-Guerrero, William Ballesteros-Possú, Jorge Fernando Navia — Tue, 24 Jan 2023 00:00:00 +0000

The characterization of production systems is important to determine limitations and potentialities that allow their management. This type of diagnosis has not been carried out in the study region; therefore, there is no information on cocoa-based agroforestry systems. Therefore, traditional cocoa farms in the municipality of Los Andes, department of Nariño (Colombia), were social and economically characterized. Basic information was reviewed and a semi-structured survey was applied to a stratified random sample of 60 cocoa farmers. Eighteen qualitative and 20 quantitative variables were analyzed simultaneously with multiple correspondence analysis (MCA) and principal components analysis (PCA). In the PCA, five components explained 58.7% of the variability. The variables with the highest contribution were farm area, income from cocoa yields, income from agricultural production other than cocoa, and family labor. In the MCA, 11 components explained 58.43% of the variability. The most important components were farmers' schooling, transport type, loans, marketing, technical assistance, gender, land tenure, production systems, roads, and domestic animals. Finally, topographic and climatic conditions, inadequate roads and marketing of cocoa and the low adoption of technologies limit the competitiveness of the cocoa farms, hence the need to create favorable conditions to enhance the potential of cocoa agroforests.

Bio regulation of Meloidogyne incognita (Kofoid & White) Chitwood and M. javanica (Treub) Chitwood complex in coffee roots

Angela Maria Castro-Toro, Carlos Alberto Rivillas-Osorio — Tue, 24 Jan 2023 00:00:00 +0000

The Meloidogyne incognita and M. javanica complex cause damage to the coffee plants’ roots with loss of productive potential. Traditional management against this complex is based on the use of chemical molecules which causes problems in soil health and harmful to the environment. In this regard, the Micosplag^® biotechnological input [Paecilomyces lilacinus (Thom) Samson, 1974, Metarhizium anisopliae (Metsch) Sorokin and Beauveria bassiana (Balsamo) Vuillemin] and Tricho-D^® (Trichoderma harzianum Rifai, 1969) were evaluated under greenhouse conditions against root-knot nematode complex. A dose of 2g. L^-1 of water was used for Micosplag^® and 10g. L^-1 of water for Tricho-D^®, applying a volume of 20mL.¹ per plant. The nematode inoculation was carried out eight days after the sowing, using 2500 eggs per plant. Bioinputs were applied preventively and also as bioregulators of an existing nematodes population. Nine treatments, which corresponded to different moments of application of bioinputs in soil and soil plus vermocompost were evaluated. Results showed the lowest levels of infection when the Micosplag^® bioinput was applied preventively (infection level of 6%), followed by the Tricho-D^® treatment (infection 12%). There were statistical differences with the controls which were inoculated alone with the nematodes. When the two Bioinputs were applied preventively, they offered greater protection to the roots against nematodes. Dry weights of root and the aerial part of the plants showed the lowest values in treatments where the nematode was inoculated. Six months after the experiment was established, the three fungi that compose the Micosplag^® Bioinput were isolated from the rhizosphere of the coffee plants.

Correlative analysis of climate impacts in an Andean municipality of Colombia

Luis Carlos Ortega , Julio Eduardo Cañón — Tue, 27 Dec 2022 00:00:00 +0000

The municipality of Pasto (Colombia) is an intermediate, emerging city of the Colombian Andes, which is vulnerable to the impacts of climate change due to its environmental conditions, mountainous morphology, moderately humid climate, and socio-economic structure. This research aims at identifying the impacts of historical trends in climate variables on the main urban elements of the municipality of Pasto. The study uses the correlational method to determine the relationships between climate variables and some impacted urban elements between 2004 and 2019. The adjusted models allow identifying possible trajectories in the evolution of urban variables affected by climate change, population growth, and culture. Results show that climate variability produces negative quadratic trajectories in crop yields and flood events; positive quadratic patterns in landslides, forest fires, the prevalence of acute diarrheal diseases (ADD), and acute respiratory infections (ARI); and linear patterns in water availability, livestock production and food security. In general, the urban variables show a departure from equilibrium when exposed to higher temperatures and precipitation, which affect the reliability of crop yields, food security, water availability, natural disasters, and public health in the municipality of Pasto.

Efficiency of inoculation methods for genotypes selection in corn ear rot disease studies

Wed, 01 Jun 2022 00:00:00 +0000

The identification of resistance of plants to pathogens is crucial for the development of hybrids by breeding programs. To achieve that, it is of great relevance to establish effective inoculation methods for characterizing genotypes with adequate plant resistance levels. Several inoculation methods have been investigated in the search for resistance to corn ear rot disease. However, studies evaluating different corn genotypes cultivated under Neotropical field conditions remain unexplored. Here, we compared three inoculation methods (i.e., aspersion, injectable, and natural) of Fusarium verticillioides in corn ears, and evaluated disease severity and grain yield of 10 corn genotypes. The experiments were conducted in two consecutive experimental corn crop (i.e., 2015 and 2016) seasons located in cities with different environmental temperatures and belonging to different Brazilian states (i.e., Gurupi – Tocantins State, Itumbiara – Goiás State, Planaltina – Brazilian Federal District, and Toledo – Paraná State). We evaluated the mass of 1000 grains and the severity of the disease. Regarding the disease severity, our results showed that the artificial inoculation was more efficient in the regions of Planaltina and Toledo, not affecting grains’ mass in these localities. The severity of disease on the conditions of Toledo was similar for the ten genotypes. However, it was possible to identify two contrasting genotypes since P4285H (low severity) and 32R48YH (medium severity) exhibited significantly more disease symptoms in all other regions. Although the differences regarding the efficiency of inoculation methods are more evident in regions with milder temperatures, the results showed that the characterization of genotypes susceptible to the pathogen is more efficient in regions with higher temperatures.

Agronomic behavior of broad bean genotypes for the Colombian high andean zone

Tue, 27 Dec 2022 00:00:00 +0000

Broad bean cultivation is considered a productive strategy and a component of food sovereignty in Southern Colombia. Therefore, this study was carried out in order to evaluate twelve promising genotypes and two commercial controls, to expand the improved varieties supply of this legume in the future. For this, an experimental assay was established with 14 treatments and four repetitions. Where, 13 agronomic traits and the reaction to the pathogen Botrytis fabae were estimated. The information was analyzed by a simple ANOVA test. Also, a Principal Component Analysis (PCA) was developed with the traits with the highest coefficient of variation. Results showed genetic diversity, with promising genotypes in relation to the controls. The number of stems, flowering days, pod formation days, pods per plant, weight of one hundred seeds, and yield allowed three groups to be identified by PCA. The first one was made up of two controls, the second group characterized by higher yields, and a third group represented by an intermediate yield added to an earliness condition. These results allow the recognition of candidate genotypes to be included into breeding programs and contribute to the crop protection.

Path analysis between fruit biometric traits of Caesalpinia ebano H. Karst

Wed, 01 Jun 2022 00:00:00 +0000

Caesalpinia ebano is a tropical tree from Colombia; its conservation status is in the endangered category since the remaining populations are suffering genetic erosion. The objective of this study was to estimate the phenotypic (rF) and genetic (rG) correlations among biometric fruit and seeds traits, and the path analysis for the fruit weight. Ten trees (treatments) were evaluated under the random effects model, with 10 fruits/tree as replications. There was significant variability between trees for seven quantitative traits. The fruit weight showed genetic correlations with six traits (0.56* > rG < 1.00**). The number and weight of the seeds per fruit showed high genetic correlations with five traits (rG ≥ 0.85**). The weight of the seeds per fruit exerted direct and indirect effects of greater importance in determining the fruit weight. It is possible to improve the production and physiological quality of the seed by directly selecting trees with fruits of greater seed weight.

Determinants of nitrogen use efficiency in coffee crops. A review

Wed, 01 Jun 2022 00:00:00 +0000

World production of coffee (Coffea spp.) has increased in recent decades due to its growing demand. Nitrogen (N) is one of the most required nutrients by coffee crops and in many cases, the most yield-limiting; nevertheless, a high percentage of supplied N is lost, generating pollution, greenhouse gases, and economic losses. Given this scenario, it is a priority to adopt practices that increase nitrogen use efficiency related to the capacity of plants to absorb and use N to produce biomass. This article provides context about NUE and determining factors in coffee: plant, soil, climate, and management. On the plant side, despite advances in genetics and the results of genotype evaluation, it may be a decade or more before improved coffee varieties with high EUN become available or used in world coffee farming. Both the physical, chemical, and biological properties of the soil and the elements of the climate, mainly temperature, precipitation, and solar radiation, have an influence on coffee growth and many of the processes that intervene in the N cycle and NUE; however, some components of these two factors are not fully controllable. Management of the factors that determine NUE should focus on reducing N losses in the system, increasing its uptake and utilization by plants, and maintaining or increasing productivity.