scholarly journals Effect of seaweed extract application on wine grape yield in Australia

2021 ◽  
Author(s):  
Tony Arioli ◽  
Scott W. Mattner ◽  
Graham Hepworth ◽  
David McClintock ◽  
Rachael McClinock
Keyword(s):  
Mixed Model ◽  
Field Experiments ◽  
Linear Mixed Model ◽  
Climate Extremes ◽  
Seaweed Extract ◽  
Wine Grape ◽  
Climate Conditions ◽  
Mixed Model Approach ◽  
Budget Analysis ◽  
Grape Yield

AbstractSeaweed extracts are agricultural biostimulants that have been shown to increase the productivity of many crops. The aim of this study was to determine the effect of a seaweed extract from the brown algae Durvillaea potatorum and Ascophyllum nodosum as a soil treatment on the yield of wine grapes grown in Australian production and climate conditions. This study used a series of seven field experiments (2012–2017), across five locations, in three Australian states and four cultivars, and analysed data using a linear mixed model approach. The analysis revealed that recurring soil applications of the seaweed extract significantly increased wine grape yield by an average of 14.7% across multiple growing years that experienced climate extremes. Partial budget analysis showed that the use of the seaweed extract increased profits depending on the grape cultivar. This study is the most extensive investigation of its type in Australian viticulture to understand the effect of a soil-applied seaweed extract on wine grape production.

Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Management Tool ◽  
American Lobster ◽  
Suitable Habitat ◽  
Climate Conditions ◽  
Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

scholarly journals A Fumonisin Prevention Tool for Targeting and Ranking Agroclimatic Conditions Favoring Exposure in French Maize-Growing Areas

Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 214
Author(s):  
Agathe Roucou ◽  
Christophe Bergez ◽  
Benoît Méléard ◽  
Béatrice Orlando
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Fusarium Verticillioides ◽  
Agricultural Practices ◽  
Climatic Conditions ◽  
Agricultural Cooperatives ◽  
Mixed Model Approach ◽  
Food And Feed ◽  
Model Approach

The levels of fumonisins (FUMO)—mycotoxins produced by Fusarium verticillioides—in maize for food and feed are subject to European Union regulations. Compliance with the regulations requires the targeting of, among others, the agroclimatic factors influencing fungal contamination and FUMO production. Arvalis-Institut du végétal has created a national, multiyear database for maize, based on field survey data collected since 2003. This database contains information about agricultural practices, climatic conditions and FUMO concentrations at harvest for 738 maize fields distributed throughout French maize-growing regions. A linear mixed model approach highlights the presence of borers and the use of a late variety, high temperatures in July and October, and a water deficit during the maize cycle as creating conditions favoring maize contamination with Fusarium verticillioides. It is thus possible to target a combination of risk factors, consisting of this climatic sequence associated with agricultural practices of interest. The effects of the various possible agroclimatic combinations can be compared, grouped and classified as promoting very low to high FUMO concentrations, possibly exceeding the regulatory threshold. These findings should facilitate the creation of a national, informative and easy-to-use prevention tool for producers and agricultural cooperatives to manage the sanitary quality of their harvest.

scholarly journals Analyzing Child Malnutrition in Bangladesh: Generalized Linear Mixed Model Approach

2016 ◽  
Vol 64 (2) ◽  
pp. 163-167
Author(s):  
Tahmidul Islam ◽  
Md Golam Rabbani ◽  
Wasimul Bari
Keyword(s):  
Mixed Model ◽  
Sampling Design ◽  
Linear Mixed Model ◽  
Generalized Linear Mixed Model ◽  
Child Malnutrition ◽  
Demographic Health Survey ◽  
Factors Affecting ◽  
Mixed Model Approach ◽  
Potential Factors ◽  
Model Approach

Child malnutrition is a serious issue for overall child health and future development. Stunting is a key anthropometric indicator of child malnutrition. Because of the nature of sampling design used in Bangladesh Demographic Health Survey, 2011, responses obtained from children under same family might be correlated. Again, children residing in same cluster may also be correlated. To tackle this problem, generalized linear mixed model (GLMM), instead of usual fixed effect logistic regression model, has been utilized in this paper to find out potential factors affecting child malnutrition. Model performances have also been compared. Dhaka Univ. J. Sci. 64(2): 163-167, 2016 (July)

scholarly journals A Novel Approach to the Design and Analysis of Field Experiments to Study Variation in the Tolerance and Resistance of Cultivars to Root Lesion Nematodes (Pratylenchus spp.)

2020 ◽  
Vol 110 (10) ◽  
pp. 1623-1631
Author(s):  
Karyn L. Reeves ◽  
Clayton R. Forknall ◽  
Alison M. Kelly ◽  
Kirsty J. Owen ◽  
Joshua Fanning ◽  
...  
Keyword(s):  
Mixed Model ◽  
Field Experiments ◽  
Linear Mixed Model ◽  
Random Regression ◽  
Yield Response ◽  
Response Curves ◽  
Model Framework ◽  
Management Options ◽  
Nematode Reproduction ◽  
Yield Response Curves

The root lesion nematode (RLN) species Pratylenchus thornei and P. neglectus are widely distributed within cropping regions of Australia and have been shown to limit grain production. Field experiments conducted to compare the performance of cultivars in the presence of RLNs investigate management options for growers by identifying cultivars with resistance, by limiting nematode reproduction, and tolerance, by yielding well in the presence of nematodes. A novel experimental design approach for RLN experiments is proposed where the observed RLN density, measured prior to sowing, is used to condition the randomization of cultivars to field plots. This approach ensured that all cultivars were exposed to consistent ranges of RLN in order to derive valid assessments of relative cultivar tolerance and resistance. Using data from a field experiment designed using the conditioned randomization approach and conducted in Formartin, Australia, the analysis of tolerance and resistance was undertaken in a linear mixed model framework. Yield response curves were derived using a random regression approach and curves modeling change in RLN densities between sowing and harvest were derived using splines to account for nonlinearity. Groups of cultivars sharing similar resistance levels could be identified. A comparison of slopes of yield response curves of cultivars belonging to the same resistance class identified differing tolerance levels for cultivars with equivalent exposures to both presowing and postharvest RLN densities. As such, the proposed design and analysis approach allowed tolerance to be assessed independently of resistance.

scholarly journals Early Growth Response of Nine Timber Species to Release in a Tropical Mountain Forest of Southern Ecuador

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 254 ◽  
Author(s):  
Omar Cabrera ◽  
Andreas Fries ◽  
Patrick Hildebrandt ◽  
Sven Günter ◽  
Reinhard Mosandl
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Growth Habit ◽  
R Package ◽  
Mountain Forest ◽  
Timber Species ◽  
Older Individuals ◽  
Humid Climate ◽  
Climate Conditions ◽  
Shade Tolerant Species

Research Highlights: This study determined that treatment “release from competitors” causes different reactions in selected timber species respective to diametrical growth, in which the initial size of the tree (diametric class) is important. Also, the growth habit and phenological traits (defoliation) of the species must be considered, which may have an influence on growth after release. Background and Objectives: The objective of the study was to analyze the diametric growth of nine timber species after their release to answer the following questions: (i) Can the diametric growth of the selected timber species be increased by release? (ii) Does the release cause different responses among the tree species? (iii) Are other factors important, such as the initial diameter at breast height (DBH) or the general climate conditions? Materials and Methods: Four-hundred and eighty-eight trees belonging to nine timber species were selected and monitored over a three-year period. Release was applied to 197 trees, whereas 251 trees served as control trees to evaluate the response of diametrical growth. To determine the response of the trees, a linear mixed model (GLMM, R package: LMER4) was used, which was adjusted by a one-way ANOVA test. Results: All species showed a similar annual cycle respective to diametric increases, which is due to the per-humid climate in the area. Precipitation is secondary for the diametric growth because sufficient rainfall occurs throughout year. What is more important, however, are variations in temperature. However, the species responded differently to release. This is because the initial DBH and growth habit are more important factors. Therefore, the species could be classified into three specific groups: Positive, negative and no response to release. Conclusions: Species which prefer open sites responded positively to release, while shade tolerant species and species with pronounced phenological traits responded negatively. The initial DBH was also an important factor for diametric increases. This is because trees of class I (20 cm to 30 cm DBH) responded positively to the treatment, whereas for bigger or older individuals, the differences decreased or became negative.

Seed Size and Burial Effects on Giant Ragweed (Ambrosia trifida) Emergence and Seed Demise

Weed Science ◽  
2007 ◽  
Vol 55 (1) ◽  
pp. 16-22 ◽  
Author(s):  
S. K. Harrison ◽  
E. E. Regnier ◽  
J. T. Schmoll ◽  
J. M. Harrison
Keyword(s):  
Seed Size ◽  
Mixed Model ◽  
Field Experiments ◽  
Linear Mixed Model ◽  
Control Measures ◽  
Habitat Modification ◽  
Agricultural Fields ◽  
Burial Depth ◽  
Growing Seasons ◽  
Giant Ragweed

Giant ragweed is a competitive, allergenic weed that persists in agricultural fields and early successional sites. Field experiments were conducted to determine the effects of seed size and seed burial depth on giant ragweed emergence and seed demise. In a seedling emergence experiment, small (< 4.8 mm in diameter) and large (> 6.6 mm in diameter) seeds were buried 0, 5, 10, and 20 cm in fall 1997, and weed emergence was monitored over the next seven growing seasons. A generalized linear mixed model fit to the cumulative emergence data showed that maximum emergence for both seed sizes occurred at the 5-cm burial depth, where probability of emergence was 19% for small seeds and 49% for large seeds. Emergence probability at the 10-cm burial depth was 9% for small seeds and 30% for large seeds, and no seedlings emerged from the 20-cm burial depth. The model predicted that ≥ 98% of total cumulative emergence was completed after four growing seasons for large seeds buried 5 cm, five growing seasons for small seeds buried 5 cm and large seeds buried 10 cm, and seven growing seasons for small seeds buried 10 cm. Seed size and burial treatment effects on seed demise were tested in a second experiment using seed packets. Rates of seed demise were inversely proportional to burial depth, and the percentage of viable seeds remaining after 4 yr ranged from 0% on the soil surface to 19% at the 20-cm burial depth. Some seeds recovered from the 20-cm burial depth were viable after 9 yr of burial. These results, coupled with previous research, suggest that seed size polymorphism facilitates giant ragweed adaptation across habitats and that a combination of no-tillage cropping practices, habitat modification, and timely weed control measures can reduce its active seed bank in agricultural fields by 90% or more after 4 yr.

Does a physical activity program in the nursing home impact on depressive symptoms? A generalized linear mixed-model approach

2017 ◽  
Vol 22 (6) ◽  
pp. 784-793 ◽  
Author(s):  
Mona Diegelmann ◽  
Carl-Philipp Jansen ◽  
Hans-Werner Wahl ◽  
Oliver K. Schilling ◽  
Eva-Luisa Schnabel ◽  
...  
Keyword(s):  
Physical Activity ◽  
Nursing Home ◽  
Depressive Symptoms ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Generalized Linear Mixed Model ◽  
Physical Activity Program ◽  
Mixed Model Approach ◽  
Activity Program ◽  
Model Approach

scholarly journals Early Response to Liberation and Climatic Seasonality of Selected Timber Species in a Tropical Mountain Forest of Southern Ecuador

2018 ◽  
Author(s):  
Omar Cabrera ◽  
Andreas Fries ◽  
Patrick Hildebrandt ◽  
Reinhard Mosandl
Keyword(s):  
San Francisco ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Early Response ◽  
Influential Factor ◽  
Mountain Forest ◽  
Timber Species ◽  
Climate Conditions ◽  
Tropical Mountain ◽  
Southern Ecuador

Research Highlights: The study determined that selective thinning causes different responses, the initial size of the tree released is an influential factor in the growth of species. The temporality of climate and physiological conditions of each species are influential in the growth. It is evident that the defoliation of certain species is an important factor that limits the growth of the species causing thinning to have a negative response. Background and Objectives: The objective is to analyze the behavior of nine timber species, respective to diametric growth after their liberation. This research aims to answer the following questions: (i) How do the selected tree species react to the liberation? (ii) Can the productivity of the trees (diametric growth) be enhanced by liberation? (iii) Are there other factors that influence the diametric growth of the released trees? Materials and Methods: The study was executed in the &ldquo;Reserva Biol&oacute;gica San Francisco&rdquo; were 488 trees were monitored, including nine timber species. Therefore, 197 trees were released (removal of competitors) and 251 trees served as reference. To check whether the initial DBH or other factors, like the selective thinning or climate conditions, determine the diameter growth a linear mixed model GLMM was applied. To adjust the linear mixed model a one-way Anova test was executed. Results: Timber species responded differently to the thinning in comparing to reference trees. Therefore, the species analyzed were separated into three groups (positive, negative, and no response to liberation). Conclusions: Liberation potentiates the growth of certain timber species that do not defoliate and considered semi-tolerant to shade. Precipitation and temperature affect all species, but in the defoliate species, it would not be convenient to release them or at least the evidence of these first three years does not show clear differences with control trees. Increase in trees released are higher in trees of the first two diametric classes in all species, this means that larger trees (i.e., older) release does not affect them in a positive way so release should occur in the youngest trees.

Local environmental conditions affecting anuran tadpoles' microhabitat choice and morphological adaptation

2019 ◽  
Vol 70 (3) ◽  
pp. 395 ◽  
Author(s):  
N. C. S. Marques ◽  
L. Rattis ◽  
F. Nomura
Keyword(s):  
Land Use ◽  
Environmental Variables ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Vegetation Type ◽  
Fine Tuning ◽  
Mixed Model Approach ◽  
Generalised Linear Mixed Model ◽  
Vegetation Heterogeneity ◽  
Microhabitat Choice

In this study, we investigated the environmental variables that best explained tadpole occurrence, as well as associations between environmental variables and the morphological traits of tadpoles. We modelled the occurrence of tadpoles to evaluate the significance of trait–environment relationships by sampling in 86 ponds, measuring a set of environmental descriptors of these ponds, determining the tadpoles’ external-morphology changes and using a generalised linear mixed model approach. The best fitting model predicting tadpole occurrence included all the environmental variables measured (pond dimensions, pond margin type, pond bottom substrate, vegetation type inside the pond, vegetation type in the pond margins, landscape descriptors) and seven morphology–environment interactions. Tadpoles are capable of fine-tuning their morphology according to the environmental traits of the pond and land use changes around the pond. Vegetation heterogeneity of ponds interacts with tadpole morphology primarily on tail size and deviations in the mean position of the eye, nostril and mouth. Moreover, there are increases in body size and tail length in smaller ponds, as well as in ponds surrounded vegetation changes from forest to pasture or short crops. Changes in environmental variables as a result of land use change can affect the dispersion of adult frogs and, consequently, the occurrence of and morphological variations in tadpoles. Local environmental variables play important roles driving tadpoles’ microhabitat choice; once tadpoles cannot select the site of their developmental, they need to compensate for any mismatching by induced morphological adaptations.

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