Section B - Life Sciences

All Items

• Alberto Macancela-Herrera, Pedro X Astudillo, Byron Ortega-Pillajo

  Validation of the empirical method for obtaining wood density of high Andean species

  The carbon present in the atmosphere is one of the main causes of global warming. However, vegetation is one of the most important carbon sinks and can be quantified through wood density. For this purpose, there are different invasive and non-invasive methodologies that use sophisticated, time-consuming and expensive equipment, but it is necessary to consider non-invasive, economical techniques that require less time. For this reason, this research aimed to i) compare the wood density obtained through the empirical method and water displacement and ii) demonstrate the validity of the empirical method as a methodology for measuring wood density for high Andean species. To perform the statistical analyses, it was necessary to group the species by growth habit (trees and shrubs), and all species were analyzed together. The comparison of means showed that wood densities did not show statistical differences (p value > 0.05), and linear regressions showed adjustments above 85% for tree, shrub and grouped species. This demonstrates the high similarity in wood density values. Previous research has found similar results to ours, and has also validated the empirical method in species from other latitudes. Based on the results of this study, it is suggested that the use of the empirical method is also suitable for measuring wood density in high Andean species. It is important to consider that this methodology reduces the work effort, time and even the use of equipment.

  DOI: https://doi.org/10.18272/aci.3775

• John Fredy Hernandez Nopsa, Juliene Andrea Barreto Rojas, Manuel Alejandro Guzmán Hernández, Karen Viviana Osorio Guerrero, Luis Felipe Rincón Manrique, Julio Ramírez Durán

  The Rematriacion of native corn (Zea mays L.) for the Kamëntsá-biyá Indigenous people, in the department of Putumayo, Colombia

  The most important challenges that humanity faces today are biodiversity loss and erosion of  germplasm  resources,  both  highly  enhanced  by  climate  change,  climate  variability,  and  anthropogenic  causes.  These  phenomena  were  identified  in  local  production  seed  systems  (SLS)  and  local  agricultural  communities  such  as  the  native  indigenous  people  Kamëntsá-biyá  in  Putumayo,  Colombia,  particularly  in  corn.  The  intercultural  dialogue  allowed  AGROSAVIA  to  reach  different  agricultural  communities  and  develop  strategies  to strengthen SLS and improve food security and food sovereignty locally. To mitigate the loss of corn landraces, AGROSAVIA prepared a strategy called Seed Rematriation, a strategy developed jointly with the Kamëntsá-biyá community. To the Kamëntsá-biyá people, the strengthening of their agricultural system (called jajañ) begins with rescuing corn landraces that were lost. Human factors or climate variability are the most common causes of this disappearance.  Seed  Rematriation  reinforces  the  agricultural,  cultural,  and  food  bases  of  local  communities.  To  rescue  corn  seed,  we  use  accessions  stored  in  the  Colombian  Germplasm  Banks  for  Food  and  Agriculture  (BGAA).  We  identified  and  increased  ten  corn accessions collected in the Putumayo and stored more than three decades ago. We agreed with the Kamëntsá-biyá people to return this seed to their community. The seed increase  was  done  at  the  AGROSAVIA  research  center  La  Selva  (Rionegro,  Antioquia).  La  Selva has optimal agroclimatic conditions to increase corn seed from the Putumayo area. Seed  increase  was  done  using  a  plot  under  controlled  pollination  per  accession,  where  we  finally  obtained  quality  seeds  of  each  accession.  Simultaneously,  we  strengthened  the  Kamëntsá-biyá  Seed  Guardian  Network  so  that  they  could  increase,  produce,  and  store  corn  seeds  using  their  cultural  practices.  Rematriation  implies  the  conscious  and  respectful return of landraces or native seeds to their communities, with the recognition of their intrinsic value and the preservation of cultural practices associated with their seeds. Rematriation  is  based  on  respect  and  cultural  understanding  and  prioritizes  community participation  during  the  strengthening  of  their  agricultural  production  systems  through  interculturality.  Finally,  seed  rematriation  contributes  to  food  security,  food  sovereignty,  and food identity. It facilitates the conservation and rescue of agrobiodiversity using both in situ and ex situ strategies. Here, we describe the rematriation principles and depict their actions  to  articulate  rescue,  conservation,  restoration,  and  increase  processes  carried  out jointly between Kamëntsá-biyá and AGROSAVIA with the BGAA. Thus, we enrich the delivery of seed to communities and strengthen the capacities of the SLS.

  DOI: https://doi.org/10.18272/aci.v16i2.3381

• Gabriela Alban, José Velásquez, Francisco Carvajal, Mario Caviedes

  Study of the productive efficiency of (Zea mays L.) amylaceous and hard corn in Ecuador

  In Ecuador, corn production is mainly concentrated in the tropical and Andean regions, with variations in grain texture, color, production levels, and productivity. The objective of this study was to estimate the efficiency of corn production and productivity, as well as seed production in the two most important geographic regions of Ecuador. To make these estimates, a simple regression analysis (p ≤ 0.05) was used, considering the crop cycle as independent variables and production, grain productivity, and seed production as dependent variables. It is estimated that the planted area for 2023 was 362,196 hectares, with hard yellow and amylaceous corn. In the coastal region, the main producing provinces are Los Ríos and Manabí, which contribute 73 % of the total production of hard yellow corn; and in the Andean region, production is mainly located in the provinces of Bolívar, Chimborazo, and Cotopaxi, which account for 82 % of the national production of amylaceous corn. The productivity of the two types of corn varies. Hard yellow corn had an average of 4.17 ha-1 from 2018 to 2023, while amylaceous corn had an average of 1.31 ha-1 from 2018 to 2022. Over the next five years, an annual increase of 8.8 % in amylaceous corn productivity is estimated, while over the next six years, the productivity of hard yellow corn is projected to increase by 3.0 % annually. Seed is one of the most important components of agricultural production, and its production costs are an indicator of the rural environment. The supply is limited in the Andean region: projections indicate an annual increase of 5.8 % over the next five years. In the coastal region, the supply and demand for seed is covered by private companies, and there is no deficit for this important component of production. One of the types of corn that will have higher demand is black corn, due to its high nutritional value. The profitability estimates for the production of quality seed of this type of corn, with a benefit/cost ratio between 1.58 and 1.70, indicate that the production of black amylaceous corn seed is profitable.

  DOI: https://doi.org/10.18272/aci.v16i2.3401

• Astrid Racancoj Coyoy, Glenda Edelmira Perez, Johny Fernando Patal Gomez

  Prospection of corn tar spot complex at central highlands of Guatemala

  Tar spot complex (TSC)  is a corn disease associated with the presence of three fungi: the first two pathogens being Phyllachora maydis and Monographella maydis, and the hyperparasite of the stromas of P. maydis known as Coniothyrium phyllachorae. This disease affects the yield of the crop, which can sometimes lead to total loss. It has predominated in tropical areas, characterized by high temperatures and high relative humidity. However, since 2015, there have been reports in the United States, Mexico and Ecuador of the presence of P. maydis in temperate to cold corn production areas. In this context, to determine the presence of pathogens associated with TSC in temperate climate areas, 48 corn fields in the department of Chimaltenango were evaluated during the second half of 2022.  In each field, the incidence and degree of infection were evaluated. In 13 locations of Chimaltenango, the presence of P. maydis stromas (shiny black spots scattered on the leaf) was detected, as well as the formation of “fish eyes”. The incidence ranged between 10 and 100 %, with a degree of infection between moderate and strong, according to the scale used. It was  confirmed that at least one of the pathogens associated with the TSC , P. maydis, is present  in the corn production areas of the central highlands of Guatemala.

  DOI: https://doi.org/10.18272/aci.v16i2.3340

• Karen Viviana Osorio Guerrero, John Freddy Rodríguez Molina, David Napoleón Vargas Ramírez, Luisa Fernanda Sarmiento Moreno, Gustavo Adolfo Rodríguez Yzquierdo, Manuel Alfonso Patiño Moscoso, Deisy Lorena Flórez Gómez

  Physiological performance of Sweet Sorghum seeds in response to Growth Retardant application

  One of the agronomic management strategies to reduce plant lodging during the production of quality sweet forage sorghum seed is the use of growth retardants; however, its effect on the physiological performance of the seeds is unknown. The objective of this study was to evaluate the physiological quality of sweet forage sorghum seeds obtained after the application of growth retardants in the vegetative state of the plant in two cultivation environments. The trials were established in two locations located in the agroecological zones: inter-Andean valleys and Colombian dry Caribbean during the first semester of 2022. The experimental design used was complete randomized blocks with three repetitions and six treatments consisting of the application of variable doses of ethephon, mepiquat chloride and trinexapac-ethyl in two stages of development of the plant (1 and 3) plus the control without application of retardants. The variables of germination percentage, viability by tetrazolium and vigor by accelerated aging, electrical conductivity and cold test were determined. The average values of germination and viability were 64% and 80% respectively, and the vigor by accelerated aging and the cold test obtained an approximate value of 62%. The results indicate that there are effects of the environment and its interaction with the retardants without affecting the physiological performance of the seeds. The existing variability in the physiological parameters of sorghum seeds is due to adverse environmental conditions towards physiological maturity and harvest.

  DOI: https://doi.org/10.18272/aci.v16i1.2998

• Ivi Flores Cabezas, Fernando Pazmiño Galarza, Nathaly Reyes Calupiña, Karla Mena Martínez, Agusto Luzuriaga-Neira, Leonardo Cedeño Jiménez, Nivia Luzuriaga

  Identification of gastrointestinal parasites in waterfowl at Yahuarcocha lagoon, Imbabura, Ecuador: Parasitic gastrointestinal infections in waterfowl

  Parasitism in wild birds is an area of study of vital importance within ecology and animal health. These infections, caused by a variety of parasites, can significantly impact the health, behavior, and dynamics of bird populations. The interaction between parasites and their avian hosts is complex and can be influenced by environmental, genetic, and behavioral factors. Understanding these processes is crucial for wildlife management, biodiversity preservation, and the prevention of zoonotic diseases that can affect humans. Parasitic infections in wild birds are widely distributed globally, with many cases being subclinical due to low parasite concentrations. A total of 48 samples from five species of waterfowl from Yahuarcocha lagoon were analyzed to determine prevalence, infestation intensity, and co-infection of parasite eggs and oocysts in bird feces. Two diagnostic techniques were used: direct coproparasitoscopic method (qualitative) and McMaster technique with Sheater’s solution (quantitative). Four genera of parasites were identified in 23 birds: Ascaridia galli, Heterakis gallinarum, Capillaria sp., and Eimeria spp. The prevalence was estimated at 48 % (23/48), with at least one of the identified genera or species. Host-specific prevalence was 60 % (3/5) in the Common Gallinule; 50 % (9/18) in the Andean Coot; 47 % (8/17) in the Neotropical Cormorant; 40 % (2/5) in the AndeanRuddy Duck; and 33 % (1/3) in the Cattle Egret. Regarding infestation intensity, birds showed average values of 271 (±74) eggs per gram (EPG) of A. galli; 275 (±98) EPG of H. gallinarum; 125 (±25) EPG of Capillaria sp., and 236 (±139) oocysts per gram (OPG) of Eimeria spp. Mixed infections were found in 30.43 % (7/23) of cases, most commonly involving H. gallinarum and Eimeria spp. in two hosts. 

  DOI: https://doi.org/10.18272/aci.v16i2.3291

• Liliana Atencio Solano, Jos´é Tapia Coronado, W Barragán Hernández, Emiro Suárez Paternina, Abelsardo Tulio Diaz Cabadiaz , Iván Javier Pastrana Vargas

  Evaluation of some physical and physiological quality attributes of sweet corn (Zea mays sacharata) seeds under different storage conditions and harvesting season

  In Colombia, sweet corn (Zea mays saccharate) is of great importance for producers and consumers of fresh grain. Agrosavia has developed a new variety of sweet corn for small producers in the Caribbean region who can produce their own seed. The study aimed to evaluate the physiological quality of sweet corn seed under different storage, packaging and harvesting conditions. Two experiments, cold storage and environmental conditions, were established at the Analytical Chemistry Laboratory of AGROSAVIA, where the effect of packaging and harvest time on germination, viability, temperature and humidity of sweet corn seeds was evaluated. The seed germination and viability under cold storage conditions (10 °C and 60 RH) were higher (P<0.05) when stored in plastic packaging (81.9 %) compared to paper (76.3 %). For environmental temperature conditions (28 °C and 85 RH), the highest germination percentage (P<0.05) was presented in the plastic packaging from 60 to 120 days of storage in seed harvested at 90 days. According to this study, sweet corn seed can be harvested at physiological maturity (90 days) and packaged in plastic containers preserving the quality for up to 120 days. Paper bag treatment germination can be drastically reduced after 60 days of storage. 

  DOI: https://doi.org/10.18272/aci.v16i2.3295

• Vicente Antonio Vera Bravo, Benny Avellan, Galo Alexander Cedeño García, Sofía del Rocío Velásquez Cedeño, Geoconda Aracely López Álava, José Luis Zambrano Mendoza

  Effectiveness of liquid fertilization and bio-stimulation on yield and profitability of maize (Zea mays L.) f or fresh consumption

  The  consumption  of  sweet  corn  is  very  important  in  some  coastal  areas  from  the  Equator . The goal of the study was to analyze the effectiveness of liquid fertilization and biostimulation on the yield and profitability of the INIAP 543 – QPM sweet corn (choclo). The work was carried out during two different rainy seasons in January-2021 and May-2022,  in  the  locations  of  El  Cady  in  Portoviejo,  Danzarín  in  Rocafuerte,  and  El  Limón  in Bolívar, located at coordinates 1°07’14.6”S - 80°24’39.7”W, 0°54’42.0”S - 80°24’17.4”W, and  0°49’49.1”S  -  80°10’48.6”W,  respectively.  The  evaluated  treatments  were  liquid  fertilization  +  bio-stimulation  (LF  +  BIO),  granular  fertilization  +  bio-stimulation  (GF  +  BIO),  granular  fertilization  (GF),  and  a  control  treatment  without  fertilization  or  bio-stimulation. A completely randomized block design was used, with four treatments and five replications. Corn ear yield (CEY ), agronomic nitrogen efficiency (ANE), and economic profitability were recorded. The treatments had a significant influence (p<0.05) on CEY and  ANE  in  both  planting  seasons  and  in  the  three  locations  evaluated.  The  LF  +  BIO  and FG + BIO treatments achieved higher CEY with averages of 9.00 and 8.43 t ha-1, with respect to the GF and control treatments with 7.76 and 3.26 t ha-1, respectively. Similarly, on average, ANE was higher in the LF + BIO and GF + BIO treatments with 38.26 and 34.47 kg of CEY kg-1 of N applied, in contrast to the FG treatment that achieved an average ANE of 30.01 of CEY kg-1 of N applied. On the other hand, LF + BIO achieved greater increases in CEY and ANE with respect to GF + BIO. Economic profitability averaged USD$0.78 and USD$0.73 per each dollar invested for the LF + BIO and GF + BIO treatments, respectively, in  comparison  to  the  profitability  of  the  GF  and  control  treatments,  which  achieved  a  profit  of  USD$0.66  and  USD$0.42  per  each  dollar  invested.  The  results  obtained  allow  us  to  conclude  that  under  rainfall  conditions,  surface  soil  moisture  depends  on  water precipitation and therefore does not guarantee a permanent field capacity in the soil. In such conditions, edaphic fertilization applied in a diluted manner can be more efficient and  convenient  than  granulated  fertilization  applied  in  a  superficial  band.  In  addition,  under  rainfall  conditions,  biostimulation  is  a  technology  that  contributes  to  boost  the  edaphic fertilization of sweet corn, and its implementation is economically viable.

  DOI: https://doi.org/10.18272/aci.v16i2.3350

• Ricardo Ernesto Preciado-Ortiz, María Gricelda Vázquez-Carrillo

  Challenges and opportunities of public and private maize breeding programs in Latin America, case Mexico

  Public founded maize breeding programs belonging to universities and research institutions in Latin America contrast to breeding programs private seed companies in several aspects such as: research founding availability, market perspective, breeding products developed, users of products, use of maize genetic divergence, breeding schemes, short medium and long term in research projects, between others. The objective of this paper is to analyzed and highlight the advantages and opportunities of universities and public research institutions by their highly specialized human resources, genetic resources of breeding germplasm, and facilities to implement medium and long term, sustainable, high impact, innovation and technological development projects, with an impact in alimentation, health, nutrition, agricultural development and food safety, and also to contribute to reduce negative effects of climate change. To be able to implement this interdisciplinary and interinstitutional projects is necessary the incidence and participation of several factors like: a) the willpower to interaction between highly specialized researchers from different disciplines belonging to different institutions, b) availability of involved institutions to allow the use of human and genetic resources and their facilities, availability of national and international research founds, c) create public politics to support innovation and technology generation research. To impact food safety, nutrition, health, social and agricultural development, since research have to be consider and inversion and a public good for Latin-American governments. As an example of medium term interdisciplinary and interinstitutional work it have been released high quality, specialty and value added maize hybrids such as High oil content, pigmented (blue and red) and pozolero type. Also, it has advances and sources of germplasm to implement research lines to obtain tolerant materials for mycotoxins (Aflatoxins and Fusarium), phosphorous use efficiency, along to other research lines to generate tolerant and efficient varieties for adverse biotic and abiotic factors produced by negative effects of climate change.  

  DOI: https://doi.org/10.18272/aci.v16i2.3383