Investigaciones Agropecuarias Research Articles

Critical Value of Soil Potassium for Potato Crops in Volcanic Soils

The critical value of soil exchangeable potassium (K) (mg K kg−1) is a valuable tool for an efficient K fertilization management in potato production systems. The aim of the present study was to determine the critical value of soil exchangeable K for potato crops grown in different environments and differing availabilities of initial exchangeable K. The data used in this study were taken from 34 experiments on K fertilization conducted in southern Chile from 1977 to 2017 by the National Potato Center at the Instituto de Investigaciones Agropecuarias (INIA). Yield responses to K fertilization rates were assessed with linear-plateau and Mitscherlich models in order to determine the critical soil exchangeable K across environments. Across experiments, the average fresh tuber yield ranged between 18 and 91 Mg ha−1. Fresh tuber yields decreased by up to 70% when no K fertilization was applied. Yield reduction was concentrated around 25% in response to K deficiency. Relative yields were described as significant by both linear-plateau and Mitscherlich models. However, relative yields were better described by the linear-plateau model (p < 0.01, R2 = 0.62; SEE = 0.11). The critical soil exchangeable K value identified with the linear-plateau model was 224 mg K kg−1. This critical K value will be useful for potato farmers that produce their crops in volcanic soils, such as Andisols. Moreover, this critical K value will help to increase K use efficiency through better K fertilization management strategies aimed at building and/or maintaining K levels in soils.

Genetic diversity and intra-racial structure of Chilean Choclero corn (Zea mays L.) germplasm revealed by simple sequence repeat markers (SSRs)

Abstract Choclero is a Chilean pre-Columbian floury corn with great economic value. The genebanks network of the Instituto de Investigaciones Agropecuarias (INIA) have preserved the largest Choclero corn collection, which is underutilized despite the existence of several Choclero breeding programs. This germplasm could serve as a valuable resource in breeding for green corn yield and cooking/eating quality. To use such materials, however, breeders need information about extent and distribution of genetic diversity present within the collection. Ten simple sequence repeats (SSRs) markers were used for population genetic analysis of 34 Choclero corn landraces collected from different places of Chile and 22 inbred lines developed by the INIA corn breeding program, of two sources: Choclero landraces and commercial hybrid S 1 segregant populations. Number of alleles, gene diversity per locus, unique alleles per locus and population structure all differ between the two germplasm groups. In the landraces group, two genetic subgroups were identified. Several landraces accessions were considered as mixed. Linking genetic diversity information with vernacular name and historical events allowed us to understand the origin of this admixed group. Our results suggest that this group are open pollinated Choclero varieties released by INIA in the 1970s. A reclassification based on the original biological status is proposed. The results highlight the importance of intra-racial studies for understanding diversification and origin of local corn accessions. Data also suggests that there is scope for exploiting the genetic diversity of Choclero germplasm for Choclero corn improvement.

Molecular, morphological and pathogenic characterization of six strains of Metarhizium spp. (Deuteromycotina: Hyphomycetes) for the control of Aegorhinus superciliosus (Coleoptera: Curculionidae)

Aegorhinus superciliosus is an important pest on blueberry (Vaccinium corymbosum L.) and other fruit trees. The use of entomopathogenic fungi as Metarhizium spp. has been evaluated for the control of this insect, but variability has been observed among different strains. The aim of this study was to characterize six promising strains of Metarhizium spp. for the control of A. superciliosus. The studied strains were QuM173c, Qu-M363, Qu-M171a, Qu-M156a, Qu-M421, and Qu-M430, all of which belonged to the Chilean Collection of Microbial Genetic Resources (ChCMGR) of the Instituto de Investigaciones Agropecuarias (INIA), Chile. Molecular characterization was made by sequencing the ITS region (Internal Transcribed Spacers, ITS-5.8S rDNA). The morphology of conidia was evaluated through scanning electron microscopy and radial colony growth was evaluated in potato dextrose agar (PDA), Sabouraud dextrose agar (SDA), agar enriched with larvae of Galleria mellonella (Lepidoptera: Pyralidae) (GA), and agar enriched with adults of A. superciliosus (AA). Pathogenicity was studied based on mortality of adults of A. superciliosus inoculated with conidia. Sequencing of the ITS-5.8S rDNA region indicates that the strains belong to the clade of M. anisopliae var. anisopliae, except for Qu-M171a, which was identified as M. anisopliae var. lepidiotum. Conidia average length for the six strains was 5.09 µm and average conidia width was 1.92 µm. Radial colony growth differences were observed between strains (p < 0.01) and between different growth media (p < 0.01). The strains exhibited the highest colony growth in the GA medium, while in the AA medium they showed the lowest (p < 0.01). Pathogenicity tests show that Qu-M430 reached a 90% mortality rate (p < 0.01). Results show that there is variability between the studied strains, which is expressed in their morphology, molecular characteristics and pathogenicity towards A. superciliosus.

Determination of genetic coefficients of three springwheat varieties under a Mediterranean environment applying the DSSAT model

The impact of climate change requires developing and validating models that help to project possible scenarios that must adapt to new varieties. This study seeks to validate and calibrate the Decision Support System for Agrotechnology Transfer (DSSAT) model as a tool that facilitates the characterization of the behavior of new varieties in the face of new scenarios generated by climate change. The determination of genetic coefficients of three bread wheat (Triticum aestivum L.) varieties was considered in the methodology; this was done with the database of the historical records of the Instituto de Investigaciones Agropecuarias (INIA) Wheat Breeding Program for the 2000 to 2011 period. Once the adjustment level of the model was dealt with, it was feasible to obtain genetic coefficients of three spring wheat varieties (Pandora-INIA, Kipa-INIA, and Millan-INIA); days from planting to anthesis variable exhibited RMSE values fluctuating between 3.5 and 9.7 depending on the variety. For total duration of days to maturity, 'Millan-INIA' exhibited a very good adjustment (RMSE = 0.25) as compared to 'Pandora-INIA' (RMSE = 1.35) and 'Kipa-INIA' (12.22). Furthermore, the coefficient of determination of the genetic coefficients indicates that the varieties have minimum vernalization requirements; these are similar to the photoperiod between 'Pandora-INIA' and 'Millan-INIA' and lower in the case of 'Kipa-INIA'. Thermal requirements for grain filling, biomass production, and plant height did not exhibit any important differences among varieties. Finally, the methodology allowed calibrating the DSSAT model and achieving a good predictive level of yields for the three varieties. The plant development parameters must be studied in greater detail because of the low association between simulated and observed values.

'INIAP-Palmira 2014': a new drought-resistance barley variety

Barley (Hordeum vulgare L.) is produced in the Ecuadorian highlands ( &gt; 3,000 m a.s.l.) primarily for self-consumption and small-scale commercialization. Not many crop species are adapted to this altitude; therefore, barley is one of a few crop species that can be grown at these locations. Severe environmental conditions can be found in the Ecuadorian highlands since the region is characterized by poor soils and water deficiency (&lt; 300 mm yr-1). The Instituto Nacional de Investigaciones Agropecuarias (INIAP) has developed 'INIAP-Palmira 2014', a hulled two-row barley variety adapted to Ecuadorian agricultural conditions in the highlands. 'INIAP-Palmira 2014' showed acceptable yield performance as compared with the most popular improved barley cultivars in different production areas located in Ecuador. However, this new barley variety showed superior performance under water stress conditions in the highlands highlands (&gt;3,000 m a.s.l.). Additionally, 'INIAP-Palmira 2014' showed disease resistance, mainly to yellow rust, in all of the locations where the new variety was evaluated.

FLORAL PHENOLOGY BEHAVIOUR OF COMMERCIALLY GROWN AND NEW INTRODUCED HAZELNUT CULTIVARS (CORYLUS AVELLANA L.) IN BIO BIO REGION, CENTRAL-SOUTH OF CHILE

The importance of floral phenological synchrony among genetically compatible pollinizers and the main cultivar in an orchard requires a permanent evaluation of commercially grown and new introduced cultivars in all different locations where hazelnut is suitable for growing. Floral phenology of introduced hazelnut cultivars and two Chilean ecotypes used as pollinizers, were evaluated during five years (2007-2011), at Santa Rosa Experimental Farm, Quilamapu Regional Research Center, Instituto de Investigaciones Agropecuarias (INIA), latitude 36’31°34”S, longitude 71°54’40”W, Chillan, Chile. The earliest cultivars shed pollen by early or middle June; ‘San Giovanni’, ‘Barcelona’, ‘TGDL’, ‘Tonda di Giffoni’, ‘Gem’, ‘Segorbe’, ‘Ennis’, ‘Pauetet’, ‘Mortarella’, ‘Ribet’, ‘Ghirara’ and ‘Ianussa Racinante’, while ‘Willamette’, ‘Montebello’, ‘Butler’, shed by middle of June and most of them during middle of July and early August; ‘Clark’, ‘Gamma’, ‘Lewis’, ‘Zeta’, ‘Santiam’, OSU 504-130 and ‘Delta’, while ‘Epsilon’ starts shedding pollen by the end of July and early August. Stigma receptivity in the other side, in the earliest ones took place by middle of May; ‘Negret’, middle or late June; ‘Mortarella’, ‘Amarillo’, ‘Barcelona’, ‘San Giovanni’ and ‘Iannusa Racinante’ and middle or end of July; ‘Ghirara’, ‘Butler’, ‘Verde’, ‘Pauetet’, ‘Lewis’, OSU 504-130, ‘Ribet’ and ‘Zeta’, while ‘Casina’, ‘Hall’s Giant’ and ‘Butler’ by end of July or early August. Finally, ‘Willamette’, ‘Gem’, ‘Segorbe’, ‘Epsilon’, ‘Ennis’, ‘Clark’, ‘Gamma’, ‘Delta’ and ‘Pauetet’ show receptive stigmas by middle or end of August.

Experiencia de producción de lechuga americana (Lactuca sativa) hidropónica, tipo NFT

&lt;p class="p1"&gt;El término hidroponía se concibe como el estudio de los cultivos sin tierra. En la actualidad, es explotada comercialmente, y al cultivo se le agrega una solución nutriente que contiene los elementos esenciales requeridos por la planta para su crecimiento, bajo distintas técnicas, como la de Cultivo con Flujo Laminar de Nutrientes o NFT, por sus siglas en inglés. &lt;/p&gt;&lt;p class="p1"&gt;En el Centro de Prácticas Docentes e Investigación Agropecuaria de la Escuela de Agronegocios del Instituto Tecnológico de Costa Rica (TEC) se cuenta, actualmente, con un sistema de este tipo NFT donde estableció una actividad de fortalecimiento que ha resultado en la observación de ciertas características a partir de la experiencia generada, de la cual se espera fomentar el uso de la hidroponía, así como divulgar información técnica y de buenas prácticas en este tipo de cultivo entre usuarios interesados. &lt;/p&gt;

Diversidad genética de una colección de hongos entomopatógenos de Ecuador utilizando un enfoque AFLP modificado

Se determinó la diversidad genética de 41 cepas ecuatorianas de hongos entomopatógenos y un aislamiento de los EEUU, de una colección mantenida por el INIAP (Instituto Nacional Autónomo de Investigaciones Agropecuarias) utilizando un protocolo modificado de AFLP (Amplified Fragment Length Polymorphism). Se encontraron índices de similitud genéticos inferiores a 0.50 y 121 bandas polimórficas. El análisis AMOVA reveló que la variación entre grupos y dentro de grupos contribuían en cantidades similares (59% y 41% respectivamente) a la variación genética total detectada. El dendograma construido a partir del coeficiente genético de Jaccard muestra doce grupos, de los cuales siete contienen aislamientos agrupados por género. De estos siete grupos, cinco contienen aislamientos agrupados en base al huésped de donde se recolectaron. Los valores de Bootstrap muestran doce relaciones filogenéticas confiables con valores de confianza mayores al 70%. El análisis de componentes principales (PCA) produjo seis grupos; cuatro de ellos contienen aislamientos asociados por género. Estos resultados sugieren la existencia de una diversidad genética considerable dentro de la colección de hongos entomopatógenos del INIAP, y una tendencia de agrupamiento relacionada con el huésped de donde fueron aislados. No se encontraron regiones genómicas comunes dentro de las cepas más virulentas de hongos entomopatógenos. La elevada diversidad genética dentro de esta colección representa una fuente potencial de genotipos con actividad bioinsecticida potente.

Effect of soil depth and increasing fertilization rate on yield and its components of two durum wheat varieties

Agronomic practices, climatic variables, and soil conditions are key factors in crop productivity. Although the effects of soil chemical properties and water and agronomic crop management are known, there is little information about effective soil depth and its influence on crop productivity. Since most crop fertilization systems are based on the productive potential associated with climatic conditions and chemical properties of the first 20 cm of soil depth, the objective of this study was to determine the importance of effective depth in terms of increasing fertilization rates on durum wheat ( Triticum turgidum L. var. durum) productivity. Two experiments were conducted in the 2006-2007 season in the Santa Rosa Experimental Station (71°54’ S, 36°31’ W, 220 m a.s.l.) of the Instituto de Investigaciones Agropecuarias (INIA) located in south central Chile. We used the hard wheat cvs. Llareta-INIA and Corcolen-INIA because both respond differently to soil physicochemical properties. Each cultivar was sown in sectors with different depths: 1) 0.45 m depth, silt loam on river material and 2) 1.0 m depth, loam on deep sediments. Fertilization was: 1) control without fertilization, 2) basal fertilization (BF) based on P, K, Ca, Mg, S, B, and Zn plus 90 kg N ha-1, and 3) BF plus 210 kg N ha-1. Grain yield, plant height, and number of stems m-2 were positively affected by increasing depth of soil profile. The increasing fertilization rate affected grain yield and plant height. Grain yield for cv. Corcolen-INIA had a greater response than cv. Llareta-INIA when soil depth was increased.

Cold tolerance evaluation in Chilean rice genotypes at the germination stage

Low temperature is the most important abiotic stress affecting rice ( Oryza sativa L.) yield in Chile. Rice in Chile is usually planted when the minimum air temperatures are below 12 °C. This temperature is lower than the optimum needed for normal rice germination. Therefore, the aim of this study was to evaluate cold tolerance in 20 experimental lines from the Rice Breeding Program of the Instituto de Investigaciones Agropecuarias (INIA), Chile, at the germination stage. Coleoptile length reduction (CRED), coleoptile length after cold treatment (CLEN), coleoptile length recovery (CREC), and coleoptile regrowth (CREG) were evaluated at 13 °C for 4 d using ‘Diamante-INIA’ as the cold-tolerant control. To find genotypes with cold tolerance (low CRED value and high CLEN, CREC, and CREG values), genotypes were ranked, a biplot of principal components, and cluster analysis were performed. No differences were found among genotypes in the ranking based on CREC value so this trait was not considered. Analysis showed that only three experimental lines had cold tolerance similar to that of ‘Diamante-INIA’; all other experimental lines exhibited intermediate to low cold tolerance. These results showed low cold tolerance of some Chilean genotypes at the germination stage, thus confirming the need to evaluate the rest of the germplasm from the Rice Breeding Program.

Short Term Impact of the Chilean Journal of Agricultural Research: A Bibliometric Analysis

In January 2007, the Chilean Journal of Agricultural Research was indexed by the Institute of Scientific Information (ISI). This paper reviews the research that has been published since 2007 by using records extracted from the Web of Science database. The papers published were mostly affiliated to researchers from Chile, and six out of the ten most-contributing countries were from Latin America. The analysis by institutions showed Universidad de Concepcion as the most prolific, although this result is not valid. A lack of standardization in the manner the Instituto de Investigaciones Agropecuarias (INIA) subscribed its address on each paper caused a disaggregation of the information. This was proven by the manual curation of each record that was affiliated to any of the centers belonging to INIA. The journal has a self-citation rate of 19.3%, value that is relatively high if compared to other journals from the same subject category listed on The Journal Citation Reports 2010. Finally, this work should be considered a bibliometric snapshot of the current situation of the journal that will serve as a benchmark when new evaluations are made in a few-years time.

Kipa-INIA, new high yield spring bread wheat variety for Chile

Kipa-INIA is a spring wheat variety (Triticum aestivum L.) originated from a cross carried out in the Wheat Plant Breeding Project of the Instituto de Investigaciones Agropecuarias (INIA), in the Centro Regional de Investigacion Quilamapu (36°31’ S; 71°54’ W) in 1993. It has an upright growth habit in the seedling stage. The adult plant is low to medium height and varies between 90 and 95 cm. The spike is white with long awns along its full length. The grain is ovate, white, and vitreous. It was sown in mid-August in the Santa Rosa Experimental Field, Chillan, head emergence occurred 90 to 95 d after sowing, i.e. is 4 to 6 d before ‘Domo-INIA’. On the mean, ‘Kipa-INIA’ sown under irrigation conditions reached a yield of 11.7% higher than the control var. Domo-INIA, and 18.1% higher in dryland soils.

Millán-INIA, New Variety of High Quality Early Spring Bread Wheat for Irrigated Soils in Central-Southern Chile

Millan-INIA is a variety of spring bread wheat (Triticum aestivum L.) originating from a cross carried out in the Wheat Plant Breeding Project of the Instituto de Investigaciones Agropecuarias (INIA), in the Centro Regional de Investigacion Quilamapu in 1995. This is a spring wheat variety with an early to medium-early head emergence and upright growth habit in the seedling stage. The adult plant is low to medium height and varies between 75 and 90 cm, with a mean of 85 cm. The spike is white with long awns along its full length. The grain is large-sized, white, and vitreous. The weight of 1000 grains varies between 50 and 59 g. It was sown in mid-August at the Santa Rosa Experimental Station (36°31? S; 71°54? W), Chillan. Head emergence occurred 88 to 89 d after sowing, which is 2 to 3 d after Ciko-INIA. On average, Millan-INIA reached a yield similar to that of the var. Ciko-INIA. This line stands out for its good resistance to disease, high protein content (11.5% mean), high sedimentation value, and high W value.

The contribution of the Millennium Seed Bank Project to ex situ plant conservation in Chile

For a long time in situ conservation has been the main approach used to protect Chilean plant diversity. However, due to the high level of endemism of its flora (50%) and an increasing human impact on wild areas, ex situ conservation has become an urgent requirement to avoid the extinction of plant populations and species. Since 2001, the Instituto de Investigaciones Agropecuarias (INIA), Chile, has been working in partnership with the Royal Botanic Gardens Kew, (Kew) through the Millennium Seed Bank Project (MSB) with the objective of conserving 20% of the Chilean flora as seeds in long-term storage. This seed conservation effort has focussed mainly on the endangered and endemic plants of the Chilean drylands. Towards the end of the first phase of the MSB some 1482 seed collections representing 850 species and subspecies have been collected and safely preserved in the INIA Seed Base Bank and duplicated at Kew. Almost 70% of the total species collected are endemic to Chile and several of them are endangered. Additionally, seed germination research has been conducted for nearly 400 species and seed collections have been used to propagate several threatened species. Germination protocols have been published and disseminated online. Over 4,500 herbarium vouchers have been collected, largely duplicated at Kew and at the national herbarium in Chile. As a result of the inputs of INIA and the MSB, collaboration has been extended to other national stakeholders, mainly for plant taxonomy and seed collecting. In this context two training courses have been run for 70 staff/students. This training has contributed to the raising of general awareness of the need for the long-term protection of Chilean plant diversity and to demonstrate the key role that ex situ seed conservation can play in meeting this need.

Evaluation of a SCAR RYSC3 Marker of the Ry adg Gene to Select Resistant Genotypes to Potato Virus Y (PVY) in the INIA Potato Breeding Program

The Potato virus Y (PVY) is distributed worldwide and is one of the most damaging viruses in terms of yield reduction in the potato (Solanum tuberosum L.) crop with losses sometimes reaching 80%. To reduce its impact, there is great interest in obtaining varieties carrying the Ryadg gene that provides extreme resistance to this virus. This couldbefacilitatedwithSCAR�(sequencecharacterizedamplifiedregion)�RYSC3�bymolecularmarker-assisted� selection (MAS). This study compared the effectiveness of the RYSC3 marker in the detection of the Ryadg gene vs. biological tests on populations of the Potato Breeding Program of the Instituto de Investigaciones Agropecuarias (INIA), Chile. Within the group of 71 progenitors, 30 plants had some kind of resistance to the virus, of which 17 were carriers of the RYSC3 marker. These genotypes came from Cornell University, Centro Internacional de la Papa (CIP), Peru, and INIA. The analysis of 460 progenies which came from three different crosses showed that 299 individualsamplifiedtheRYSC3�markerandhadtheresistantphenotype,�withtheexceptionofoneplant.�Within� thegroupofnon-RYSC3�carrierplants,�asignificantpercentage�(22.5%)�showedaresistantphenotype,�indicating� that these progenies segregate other R genes (e.g., hypersensitivity) that reduce biological test effectiveness. This high effectiveness (99.7%) in the detection of the Ryadg gene in both parents and segregating progenies, showed that this marker is appropriate in assisting selection of genotypes with extreme PVY-resistance in the potato breeding programs.

Potassium and Phosphorus in Muscat Rosada Grape Yield in Elqui Valley Soil

A B S T R A C T The effects of P and K on grapevines (Vitis vinifera L.) var. Muscat Rosada were evaluated four years, considering the same levels of N. The experiment was conducted at the Vicuna Experimental Station (30° S; 70°44´ W) of the Instituto de Investigaciones Agropecuarias (INIA). The soil is alluvial antropic miscellaneous (Entisols). Three fertilization treatments were established: 1) N 160 + P2O5 200 + K2O 300; 2) N 160 + P2O5 0 + K2O 300; and 3) N 160 + P2O5 200 + K2O 0. At the beginning of the experiment, grape vines received all the phosphate fertilizers, 200 kg ha -1 of P2O5 as triple superphosphate in Treatments 1 and 3. Nitrogen was applied as urea for four years. The applications were initiated when the vine buds measured 20 cm. The K was applied to the soils of Treatments 1 and 2, at a dosage of 200 kg ha -1 K2O, using potassium sulphate. Between berry set and 30 d before harvest, 100 kg ha -1 K2O were applied as potassium sulphate by fertigation. Significant effects of the P fertilization were observed by the second year, with increased cluster numbers per plant. K also increased grape fruit yield by the third year. This response was obtained with less than 5 mg kg -1 of P available in the soil and less than 145 mg kg -1 of exchangeable K in the soil. The initially low content of available K and P suggests a high probability of response to the application of both elements.

Building Institutional Capacity for On-Farm Research: Call System Training Courses

Building Institutional Capacity for On-Farm Research: Call System Training Courses

The relevance of gender in farming systems research: Experiences in Ecuador

The purpose of this paper is to share the experiences of one national agricultural research institution in the incorporation of gender into farming systems research. The reported incorporation is partial and unsystematic, because gender is far from institutionalized in Ecuador. Nevertheless, field experience suggests that gender is an important variable to be considered in the development and dissemination of agricultural technologies. The Instituto Nacional de Investigaciones Agropecuarias (INIAP) is the state agency responsible for applied agricultural research, and it has worked with different client groups. This paper organizes INIAP's diverse experiences by considering how gender is relevant to different phases of farming systems research. It also invites people with field experience to reconsider how gender is relevant to programming in their area of expertise.