Fitomejoramiento participativo, evaluación y colección de materiales de maíz criollos en el Municipio de San Pedro Pinula, Jalapa, Guatemala, C.A.

La presente investigación se realizó en el Municipio de San Pedro Pinula, Jalapa, Guatemala, mediante el diagnóstico realizado a la producción del cultivo de maíz se encontró que en el área, el cultivo es poco tecnificado debido a la falta de asistencia técnica e introducción de tecnología. Es por ello que se realizó una colección de materiales de maíz criollos de la región para su posterior evaluación y así poder encontrar variedades que mejor se adapten a los sistemas de producción del área y las condiciones climáticas adversas que se presentan, debido a que el cultivo es exclusivamente de temporal. También se determinó que el flujo genético a nivel local constituye el principal elemento que facilita la obtención de semilla a nivel de comunidad, ya que el 94% de los agricultores utilizan semilla local, esto nos da a entender la importancia que tienen los sistemas locales de producción de semillas en la seguridad alimentaria de la comunidad. La aplicación de metodologías de Fitomejoramiento Participativo son de vital importancia debido a que el mismo agricultor forma un papel determinante en la evaluación de las variedades, posibilitando disponer de mayor información para la toma de decisiones en la selección, implementación y desarrollo de nuevas variedades. De los materiales evaluados bajo condiciones de estrés hídrico se presentaron algunas variedades mejoradas por el ICTA con rendimientos hasta de 5000 kg/ha y algunas variedades locales con rendimientos entre 3000 y 3500 kg/ha, cabe destacar que estos materiales locales superaron en rendimiento a variedades mejoradas como ICTA B-1, ICTA B-5 e ICTA B-7 en un 47%, posiblemente debido a una mejor adaptabilidad a las condiciones climáticas. Es importante disponer de información de los materiales locales, que en un futuro pueden ser la base para el desarrollo de nuevas variedades que eleven el rendimiento actual

Null, base, stimulus, experience, landscape, and full models created using forward-stepwise model building.

<p>We used Cox proportional hazards regression to model the probability of flight by adult Ferruginous Hawks from the nest when approached by an investigator. AIC indicates Akaike's Information Criterion Score [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0177584#pone.0177584.ref057" target="_blank">57</a>] used to select for covariates that best fit our data. <i>h</i>_<i>ij</i> (<i>t</i>) is the relative hazard at distance from the nest (<i>d</i>) given the value of <i>x</i> for the <i>j</i>^th nest approach in the <i>i</i>^th nesting attempt (the random effect). <i>α</i>_<i>i</i> parameterizes the latent variation between nesting attempts.</p

Covariates considered for inclusion in a Cox proportional hazards regression model of adult Ferruginous Hawk flight initiation distances when approached by investigators.

<p>Covariates considered for inclusion in a Cox proportional hazards regression model of adult Ferruginous Hawk flight initiation distances when approached by investigators.</p

Marginal effects plots demonstrating the effect size, or change to the relative hazards (exp[βi]), defined as relative changes to the probability of flight by adult Ferruginous Hawk from the nest at given distances from the nest, for each covariate in our full model.

<p>Each subplot: describes one of six covariates in our full model: a) ordinal date, b) nest structure, c) year, d) approach type, e) approach number, and f) near-traffic index within 4400 m, respectively. H, R, A, W, and E (d) represent driving on highways, range roads, access roads, walking, and exiting the truck, respectively.</p

Daily traffic volume (vehicles / day) as recorded by 178 traffic counters installed on roads throughout the range of Ferruginous Hawks in Alberta and Saskatchewan.

<p>We present the means (), standard errors (SE), and numbers of roads (n).</p

Kaplan-Meier (KM) failure estimator (Kaplan and Meier 1958) used to plot the probability of flight by adult Ferruginous Hawks from the nest at a given distance (a), specifying that they were exposed to investigators at those distances and had not previously initiated flight during the approach, and the sample size (number of instances) for which Ferruginous Hawks were exposed to an approach (b).

<p>Separate probability and sample size plots are shown for investigator approaches along highways, range roads and access roads. Additionally, separate plots are shown for walking (approaches on foot) and exiting the vehicle (the act of investigators parking and exiting their vehicle).</p

Histogram showing the frequency distribution of Ferruginous Hawk flight initiation distances during investigator nest approaches.

<p>Flight initiations were documented in southern Alberta and Saskatchewan from 2012–2014. The dashed and dash-dot vertical lines indicate the mean (130 m) and the 95th percentile (450 m) flight initiation distances, respectively.</p

Use of bird carcass removals by urban scavengers to adjust bird-window collision estimates

Carcass removal by scavengers has been identified as one of the largest biases in estimating bird mortality from anthropogenic sources. Only two studies have examined carcass removal by scavengers in an urban environment, and previous estimates of bird-window collision mortality at houses have relied on carcass removal rates from wind turbine studies. We placed a bird carcass and time-lapse camera at 44 houses in Edmonton, Alberta. In total, 166 7-day trials were conducted throughout 2015. Time-to-event (survival) analysis was used to identify covariates that affected removal. The carcass removal rate was determined for use in estimating the number of birds killed from bird-window collisions at houses in Alberta. In total, 67.5% of carcasses were removed. The date the carcass was placed, the year the house was built, and the level of development within 50 m of the house were the covariates that had the largest effect on carcass removal. In calculating our removal rate, the number of detected carcasses in the first 24 hours was adjusted by 1.47 to account for removal by scavengers. Previously collected citizen science data were used to create an estimate of 957,440 bird deaths each year in Alberta as a result of bird-window collisions with houses. This number is based on the most detailed bird-window collision study at houses to date and a carcass removal study conducted in the same area. Similar localized studies across Canada will need to be completed to reduce the biases that exist with the previous bird-window collision mortality estimate for houses in Canada