Evaluación de materiales de palma de aceite potencialmente utilizables en regiones con limitaciones de agua

Colombia es el cuarto productor a nivel mundial de aceite de palma con una participación del 2,4% de la producción global y se espera llegar a un 9% a mediano plazo, motivo que ha llevado al gremio palmicultor colombiano a impulsar el incremento de la productividad mediante estrategias que permitan superar las problemáticas del cultivo. Las limitaciones ambientales, como el déficit hídrico, tienen un efecto marcado en la productividad, que sumadas al cambio climático y al aumento de zonas en proceso de desertificación vislumbran un escenario crítico para la agricultura, razón por la cual es necesario determinar si existen cultivares comerciales con tolerancia al déficit hídrico que puedan ser sembrados en zonas con condiciones limitantes de agua. Solucionar preguntas cómo ¿cuál es el consumo de agua por parte de la palma?, ¿Cuál es el impacto de la época seca sobre el cultivo de palma de aceite? ¿Cómo discriminar cultivares de palma de aceite con tolerancia al déficit hídrico? permiten tener un camino de desarrollo sostenible para el gremio palmicultor sorteando la incertidumbre que genera el cambio climático. En esta tesis se desarrollaron 4 trabajos para responder a estas preguntas con el fin de encontrar cultivares comerciales de palma de aceite sembrados en Colombia con tolerancia al déficit hídrico. Se desarrolló un trabajo en la zona oriental de Colombia donde se determinó, mediante la evaluación ecofisiológica, el impacto que tiene la época seca en el cultivo de palma de aceite. En la zona central se desarrollaron 3 trabajos: i) Mediante la técnica de medición de flujo de savia se determinó el consumo de agua por parte de la palma de aceite. ii) Se evaluó la respuesta ecofisiológica a épocas contrastantes en palmas adultas de 11 cultivares comerciales de palma de aceite. iii) En casa de mallas se evaluó la respuesta de variables fisiológicas y bioquímicas de 11 cultivares comerciales de palma en estado juvenil sometidos a cuatro tensiones hídricas del suelo. De acuerdo a estos experimentos se encontró que: i) La palma de aceite tiene una transpiración promedio de 1,15 mmdía-1 bajo las condiciones de estudio. ii) se evidenció que la época seca afecta significativamente a la palma de aceite ocasionando una reducción en la tasa fotosintética y en la tasa transpiratoria de la palma hasta de un 70%. iii) La variabilidad genética de los cultivares comerciales de palma de aceite evaluados muestra una respuesta ecofisiológica diferencial respecto a la época de medición, siendo los cultivares IRHO 1001, IRHO 1401, Corpoica, Unilever y el híbrido OxG 2783 los que mostraron un alto potencial para afrontar periodos secos. iv) Mediante la evaluación en casa de mallas se logró determinar que los cultivares IRHO 7001 e IRHO1001 presentaron el mayor grado de tolerancia al déficit hídrico, motivo por el cual son los cultivares que mayor uso potencial tienen para ser sembrados en las zonas del país con limitaciones hídricas. Adicionalmente, se generó una metodología1 de selección temprana de cultivares con tolerancia al déficit hídrico, herramienta que puede llegar a disminuir significativamente los tiempos en los procesos de mejoramiento genético de palma de aceite.Abstract: Colombia is the fourth-largest producer of palm oil in the world with a share of 2.4% of global production and is expected to reach 9% in the medium term. That has led the Colombian palm sector to promote productivity through strategies that overcome crop limitations. Environmental limitations to the crop, such as water deficit, have a marked effect on yield, which added to climate change and the increase in desertification process zones envision a critical scenario for agriculture. Which is why it is necessary to determine whether there are commercial cultivars of oil palm with tolerance to water deficit; mainly to promote its use in areas with limiting water conditions. Solving questions such as: What is the water consumption of the palm? What is the impact of the dry season on the cultivation of oil palm? How to discriminate cultivars of oil palm with tolerance to water deficit? Allow us to have a sustainable development path for the palm growers in such a way that they can overcome the uncertainty created by climate change. In this thesis, four studies were developed to answer these questions with the aim of finding commercial cultivars of oil palm with tolerance to the water deficit; with focus on cultivars already planted in Colombia. The initial work was carried out in the eastern of Colombia, where the impact of the dry season on oil palm crops was determined through an ecophysiological evaluation. Later, in the central zone, three works were developed. i) By using a method of sap flow measurement, the water intake by oil palms was defined. ii) The ecophysiological response to contrasting epochs in adult palms of 11 commercial oil palm cultivars was evaluated. iii) The response of physiological and biochemical variables was evaluated on 11 seedling commercial palm cultivars subjected to four soil water tensions. According to these experiments, it was found that: i) The oil palm has an averaged transpiration of 1.15 mm.day-1 under the study conditions. ii) It was evidenced that the dry season significantly affects the oil palm causing a reduction in the photosynthetic rate and the transpiratory rate of the palm up to 70%. iii) The genetic variability of the commercial oil palm cultivars evaluated shows a differential ecophysiological response concerning the time of measurement, the cultivars IRHO 1001, IRHO 1401, Corpoica, Unilever, and the hybrid OxG 2783 are the ones that showed a high potential to face dry seasons. iv) through an evaluation in the mesh house, it was possible to determine that the cultivars IRHO 7001 and IRHO1001 had the highest degree of tolerance to water deficit. Thus, its use is recommended in areas of the country with water limitations. Additionally, a methodology of early selection of cultivars with tolerance was generated; this tool will significantly diminish the time of the breeding processes of oil palm.Doctorad

Estimation of transpiration in oil palm (Elaeis guineensis Jacq.) with the heat ratio method

Sap flow sensors were installed on the leaf petioles of 5-year-old oil palms (Elaeis guineensis Jacq.) to measure the xylem water flow for 12 days based on the heat ratio method (HRM). It was found that young leaves have higher sap flow rates, reaching values of over 250 cm3 h-1, and that sap flow fluctuations are directly related to weather conditions, particularly the vapor pressure deficit (VPD) component. It was observed that the sap flow rates remained constant and very close to 0 cm3 h-1 between 18:00 and 6:00 h and that the upward and downward movement of sap was faster during the day, with peak levels between 9:00 and 16:00 h. Under the evaluation conditions, the oil palm crop transpiration was estimated to be 1.15 mm H2O/ha-day. The HRM is a highly repeatable method and an useful tool to quantify the total oil palm transpiration. It could potentially be applied to irrigation

Impacts of the dry season on the gas exchange of oil palm (iElaeis guineensis/i) and interspecific hybrid (iElaeis oleifera/i x iElaeis guineensis/i) progenies under field conditions in eastern Colombia

Elaeis guineensis palms and its interspecific hybrid (E. oleifera × E. guineensis) were planted in 2004 in the Cuernavaca farm of Unipalma S.A., located in the municipality of Paratebueno Cundinamarca, Colombia). The palms were planted in two fields: Mecasaragua and Aurora. The first field has never been irrigated, and the second one (Aurora) has always been floodirrigated during the dry season according to the parameters of the plantation. In this study, physiological parameters (gas exchange and water potential) were assessed in three seasons of the year 2013 (dry season, dry-to-wet transition season and wet season). Significant gas exchange differences were found among the seasons in the field with no irrigation (Mecasaragua). Likewise, differences between the genetic materials were observed during the dry season. For example, the hotosynthesis decreased by 75% compared with the palms planted in the irrigated field. No differences among seasons or materials were found in the irrigated field (Aurora). E. guineensis palms were more sensitive to water stress compared with the O×G interspecific hybrid. Both genetic materials responded rapidly to the first rains by leveling their photosynthetic rates and demonstrated an excellent capacity to recover from water stress

CO2 soil emission under different methods of oil palm replanting

Colombian oil palm plantations have started a largescalereplanting phase. The replanting process has an effect onthe disposal of biomass, plant health management, and agroecological conditions due to the disturbance that is generated.This document addresses soil respiration (CO2 flux) as a responsevariable of crop replanting. Seven renovation methods used inColombia were tested. The measurements were taken over timeafter the disturbance and planting of the new crop. This study wascarried out in the municipality of Tumaco between August of 2009 and June of 2011 using 7 methods of renovation and 4 stages of crop development. The CO2 flow was measured at 12 points in each plot. There were no significant differences for the CO2 emission among the replanting methods. The average value for respiration was 929 mg CO2 m-2 h-1 (± 270.3); however, significant differences were found over time.This response was not related to fluctuations of soil temperatureand moisture; therefore, there should be an associated responseto biotic factors (microbial organisms) not established in thisstudy. The values suggested that the soil of the plots under areplanting process emitted considerable quantities of carbon intothe atmosphere, but the emissions declined over time and, in turn,were offset by the photosynthesis of the new crop (14 μ CO2 m-2s-1 ± 1.4, data not shown), creating an overall positive carbon balance

Estimation of transpiration in oil palm (<i>Elaeis guineensis</i> Jacq.) with the heat ratio method

Sap flow sensors were installed on the leaf petioles of 5-year-old oil palms (Elaeis guineensis Jacq.) to measure the xylem water flow for 12 days based on the heat ratio method (HRM). It was found that young leaves have higher sap flow rates, reaching values of over 250 cm3 h-1, and that sap flow fluctuations are directly related to weather conditions, particularly the vapor pressure deficit (VPD) component. It was observed that the sap flow rates remained constant and very close to 0 cm3 h-1 between 18:00 and 6:00 h and that the upward and downward movement of sap was faster during the day, with peak levels between 9:00 and 16:00 h. Under the evaluation conditions, the oil palm crop transpiration was estimated to be 1.15 mm H2O/ha-day. The HRM is a highly repeatable method and an useful tool to quantify the total oil palm transpiration. It could potentially be applied to irrigation

Impacts of the dry season on the gas exchange of oil palm (<i>Elaeis guineensis</i>) and interspecific hybrid (<i>Elaeis oleifera</i> x <i>Elaeis guineensis</i>) progenies under field conditions in eastern Colombia

Elaeis guineensis palms and its interspecific hybrid (E. oleifera × E. guineensis) were planted in 2004 in the Cuernavaca farm of Unipalma S.A., located in the municipality of Paratebueno Cundinamarca, Colombia). The palms were planted in two fields: Mecasaragua and Aurora. The first field has never been irrigated, and the second one (Aurora) has always been floodirrigated during the dry season according to the parameters of the plantation. In this study, physiological parameters (gas exchange and water potential) were assessed in three seasons of the year 2013 (dry season, dry-to-wet transition season and wet season). Significant gas exchange differences were found among the seasons in the field with no irrigation (Mecasaragua). Likewise, differences between the genetic materials were observed during the dry season. For example, the hotosynthesis decreased by 75% compared with the palms planted in the irrigated field. No differences among seasons or materials were found in the irrigated field (Aurora). E. guineensis palms were more sensitive to water stress compared with the O×G interspecific hybrid. Both genetic materials responded rapidly to the first rains by leveling their photosynthetic rates and demonstrated an excellent capacity to recover from water stress

Emisiones de CO2 de suelo bajo diferentes métodos de renovación en palma de aceite

Colombian oil palm plantations have started a large-scale replanting phase. The replanting process has an effect on the disposal of biomass, plant health management, and agro-ecological conditions due to the disturbance that is generated. This document addresses soil respiration (CO2 flux) as a response variable of crop replanting. Seven renovation methods used in Colombia were tested. The measurements were taken over time after the disturbance and planting of the new crop. This study was carried out in the municipality of Tumaco between August of 2009 and June of 2011 using 7 methods of renovation and 4 stages of crop development. The CO2 flow was measured at 12 points in each plot. There were no significant differences for the CO2 emission among the replanting methods. The average value for respiration was 929 mg CO2 m-2 h-1 (± 270.3); however, significant differences were found over time. This response was not related to fluctuations of soil temperature and moisture; therefore, there should be an associated response to biotic factors (microbial organisms) not established in this study. The values suggested that the soil of the plots under a replanting process emitted considerable quantities of carbon into the atmosphere, but the emissions declined over time and, in turn, were offset by the photosynthesis of the new crop (14 μ CO2 m-2s-1 ± 1.4, data not shown), creating an overall positive carbon balance.La palmicultura colombiana comenzó una fase a gran escala de renovación de cultivo; diversos aspectos influyen en esta situación, dentro de los más relevantes está la disposición de la biomasa y su impacto en el área fitosanitaria, y la condición agroecológica debido al disturbio generado. En este documento se abordó la respiración del suelo (flujo de CO2) como variable respuesta a la renovacion del cultivo. El trabajo se llevó a cabo en el municipio de Tumaco, entre agosto de 2009 y junio de 2011, en 7 métodos de renovación y en 4 fases de desarrollo del cultivo se midió el flujo de CO2 en 12 puntos de cada parcela. Dentro de los métodos no se evidenciaron diferencias de emisión de CO2. El valor promedio fue de 929 mg CO2 m-2 h-1 (± 270,3), sin embargo a través del tiempo se encontraron diferencias significativas, esta respuesta no está relacionada con las fluctuaciones de temperatura y humedad del suelo, por lo tanto debe existir una respuesta asociada a factores bióticos (microbiota) no establecida en este trabajo. Los valores sugieren que desde el suelo de lotes en proceso de renovación se emiten cantidades considerables de carbono hacia la atmósfera, pero que van disminuyendo a través del tiempo y a su vez son ampliamente niveladas con la fotosíntesis del nuevo cultivo (14 μ CO2 m-2s-1 ± 1,4 datos no mostrados), generando un balance positivo en estado global del carbono

CO2 soil emission under different methods of oil palm replanting

<p>Colombian oil palm plantations have started a largescale<br />replanting phase. The replanting process has an effect on<br />the disposal of biomass, plant health management, and agroecological conditions due to the disturbance that is generated.<br />This document addresses soil respiration (CO2 flux) as a response<br />variable of crop replanting. Seven renovation methods used in<br />Colombia were tested. The measurements were taken over time<br />after the disturbance and planting of the new crop. This study was<br />carried out in the municipality of Tumaco between August of 2009 and June of 2011 using 7 methods of renovation and 4 stages of crop development. The CO2 flow was measured at 12 points in each plot. There were no significant differences for the CO2 emission among the replanting methods. The average value for respiration was 929 mg CO2 m-2 h-1 (± 270.3); however, significant differences were found over time.<br />This response was not related to fluctuations of soil temperature<br />and moisture; therefore, there should be an associated response<br />to biotic factors (microbial organisms) not established in this<br />study. The values suggested that the soil of the plots under a<br />replanting process emitted considerable quantities of carbon into<br />the atmosphere, but the emissions declined over time and, in turn,<br />were offset by the photosynthesis of the new crop (14 μ CO2 m-2s-1 ± 1.4, data not shown), creating an overall positive carbon balance.</p