Spatio-temporal Patterns of Pre-harvest Brown Rot Epidemics within Individual Peach Tree Canopies

Tree canopies are architecturally complex and pose several challenges for measuring and character-izing spatial patterns of disease. Recently developed methods for fine-scale canopy mapping and three-dimensional spatial pattern analysis were applied in a 3-year study to characterize spatio-temporal development of pre-harvest brown rot of peach, caused by Monilinia fructicola, in 13 trees of different maturity classes. We observed a negative correlation between an index of disease aggregation and disease incidence in the same tree (r = −0.653, P \u3c 0.0001), showing that trees with higher brown rot incidence had lower aggregation of affected fruit in their canopies. Significant (P ≤ 0.05) within-canopy aggregation among symptomatic fruit was most pronounced for early-maturing cultivars and/or early in the epidemic. This is consistent with the notion of a greater importance of localized, within-tree sources of inoculum at the beginning of the epidemic. Four of five trees having \u3e10 blossom blight symptoms per tree showed a significant positive spatial association of pre-harvest fruit rot to blossom blight within the same canopy. Spatial association analyses further revealed one of two out-comes for the association of new fruit rot symptoms with previous fruit rot symptoms in the same tree, whereby the relationship was either not significant or exhibited a significant negative associa-tion. In the latter scenario, the newly diseased fruit were farther apart from previously symptomatic fruit than expected by random chance. This unexpected result could have been due to uneven fruit ripening in different sectors of the canopy, which could have affected the timing of symptom devel-opment and thus led to negative spatial associations among symptoms developing over time in a tree

Spatio-temporal Patterns of Pre-harvest Brown Rot Epidemics within Individual Peach Tree Canopies

Tree canopies are architecturally complex and pose several challenges for measuring and character-izing spatial patterns of disease. Recently developed methods for fine-scale canopy mapping and three-dimensional spatial pattern analysis were applied in a 3-year study to characterize spatio-temporal development of pre-harvest brown rot of peach, caused by Monilinia fructicola, in 13 trees of different maturity classes. We observed a negative correlation between an index of disease aggregation and disease incidence in the same tree (r = −0.653, P \u3c 0.0001), showing that trees with higher brown rot incidence had lower aggregation of affected fruit in their canopies. Significant (P ≤ 0.05) within-canopy aggregation among symptomatic fruit was most pronounced for early-maturing cultivars and/or early in the epidemic. This is consistent with the notion of a greater importance of localized, within-tree sources of inoculum at the beginning of the epidemic. Four of five trees having \u3e10 blossom blight symptoms per tree showed a significant positive spatial association of pre-harvest fruit rot to blossom blight within the same canopy. Spatial association analyses further revealed one of two out-comes for the association of new fruit rot symptoms with previous fruit rot symptoms in the same tree, whereby the relationship was either not significant or exhibited a significant negative associa-tion. In the latter scenario, the newly diseased fruit were farther apart from previously symptomatic fruit than expected by random chance. This unexpected result could have been due to uneven fruit ripening in different sectors of the canopy, which could have affected the timing of symptom devel-opment and thus led to negative spatial associations among symptoms developing over time in a tree

Spatial Patterns of Brown Rot Epidemics and Development of Microsatellite Markers for Analyzing Fine-Scale Genetic Structure of \u3ci\u3eMonilinia fructicola\u3c/i\u3e Populations Within Peach Tree Canopies

To better understand the fine-scale spatial dynamics of brown rot disease and corresponding fungal genotypes, we analyzed three-dimensional spatial patterns of pre-harvest fruit rot caused by Monilinia fructicola in individual peach tree canopies and developed microsatellite markers for canopy-level population genetics analyses. Using a magnetic digitizer, high-resolution maps of fruit rot development in five representative trees were generated, and M. fructicola was isolated from each affected fruit. To characterize disease aggregation, nearest-neighbor distances among symptomatic fruit were calculated and compared with appropriate random simulations. Within-canopy disease aggregation correlated negatively with the number of diseased fruit per tree (r = −0.827, P = 0.0009), i.e., aggregation was greatest when the number of diseased fruit was lowest. Sixteen microsatellite primers consistently amplified polymorphic regions in a geographically diverse test population of 47 M. fructicola isolates. None of the test isolates produced identical multilocus genotypes, and the number of alleles per locus ranged from 2 to 16. We are applying these markers to determine fine-scale population structure of the pathogen within and among canopies

Spatial Patterns of Brown Rot Epidemics and Development of Microsatellite Markers for Analyzing Fine-Scale Genetic Structure of \u3ci\u3eMonilinia fructicola\u3c/i\u3e Populations Within Peach Tree Canopies

To better understand the fine-scale spatial dynamics of brown rot disease and corresponding fungal genotypes, we analyzed three-dimensional spatial patterns of pre-harvest fruit rot caused by Monilinia fructicola in individual peach tree canopies and developed microsatellite markers for canopy-level population genetics analyses. Using a magnetic digitizer, high-resolution maps of fruit rot development in five representative trees were generated, and M. fructicola was isolated from each affected fruit. To characterize disease aggregation, nearest-neighbor distances among symptomatic fruit were calculated and compared with appropriate random simulations. Within-canopy disease aggregation correlated negatively with the number of diseased fruit per tree (r = −0.827, P = 0.0009), i.e., aggregation was greatest when the number of diseased fruit was lowest. Sixteen microsatellite primers consistently amplified polymorphic regions in a geographically diverse test population of 47 M. fructicola isolates. None of the test isolates produced identical multilocus genotypes, and the number of alleles per locus ranged from 2 to 16. We are applying these markers to determine fine-scale population structure of the pathogen within and among canopies

Deep inelastic events containing a forward photon as a probe of small xx dynamics

We calculate the rate of producing deep inelastic events containing an energetic isolated forward photon at HERA. We quantify the enhancement arising from the leading $\log 1/x$ gluon emissions with a view to using such events to identify the underlying dynamics.Comment: 11 pages, Latex, 7 ps figure

Mechanochemical synthesis of cooperative spin crossover materials

We describe the synthesis of switchable spin crossover materials via mechanochemistry for the first time. Three chemically diverse spin crossover materials have been produced using solvent-free grinding. Crucially, cooperative spin transition behavior and crystallinity is retained, presenting exciting opportunities for the discovery of new materials with switchable magnetic, optical and structural properties

She\u27ll be ‘right… but are they? An Australian perspective on women in high performance sport coaching

Participation and media coverage of women in high-performance sport has been steadily increasing in recent years throughout the world. While this increase in interest has led to many young women and girls becoming involved in grassroots sport, there has yet to be a significant change in the number of women in coaching roles, particularly at the high-performance level. This paper synthesizes and summarizes the current challenges facing women sport coaches in Australia, drawing from existing research, media and government reports to understand the barriers for women entering and progressing in these roles. We also present some of the more recent initiatives to increase opportunities for women in high performance coaching. Within Australia, there is a need to (1) understand the pipeline for women coaches, (2) examine the interacting contexts and constraints that women are subject to within sporting organizations, and (3) create a preliminary framework for future research, outreach, and education to address gender inequity within Australian sport coaching

A Numerical Estimate of the Small-kTk_T Region in the BFKL Pomeron

A computer study is performed to estimate the influence of the small-$k_T$ region in the BFKL evolution equation. We consider the small-x region of the deep inelastic structure function $F_2$ and show that the magnitude of the small-$k_T$ region depends on $Q^2$ and $x_B$. We suggest that the width of the $\log k_T^2$-distribution in the final state may serve as an additional footprint of BFKL dynamics. For diffractive dissociation it is shown that the contribution of the infrared region is large - even for large $Q^2$. This contribution becomes smaller only if restrictions on the final state are imposed.Comment: 15 pages, latex, 9 figures ,revised version, some discussion added, one reference added, two figures removed, final version to be published in Phys. Lett.