Spatial pattern of Cercospora leaf spot of sugar beet in fields in long- and recently-established areas

Vereijssen, Jessica; Schneider, Johannes; Stein, Alfred; Jeger, Michael

doi:10.1007/s10658-006-9046-z

Cited by 15 publications
(17 citation statements)

References 23 publications

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“…Thus, trees with higher brown rot incidence had lower aggregation of affected fruit within their canopies. Decreasing spatial structure with increasing disease incidence is also commonly observed in studies reporting two-dimensional spatial analyses, e.g., among plants within a field (Pethybridge et al 2010; Vereijssen et al 2006). In the present study, there was no correlation between the index of disease aggregation and the total number of fruit per tree (P = 0.321).…”

Section: Resultssupporting
confidence: 61%

Spatio-temporal patterns of pre-harvest brown rot epidemics within individual peach tree canopies
Everhart
¹
,
Askew
²
,
Seymour
³

et al. 2012
Eur J Plant Pathol
12
0
7
0
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Tree canopies are architecturally complex and pose several challenges for measuring and characterizing 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 < 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, withintree sources of inoculum at the beginning of the epidemic. Four of five trees having >10 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 outcomes 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 association. 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 development and thus led to negative spatial associations among symptoms developing over time in a tree.

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Section: Resultssupporting
confidence: 61%

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“…Conidia produced within the lesions enable multiple infection cycles to occur within one growing season and result in polycyclic disease epidemics [38]. The dispersal of conidia by rain splash and wind-blown rain infers short dispersal distances from 'local' inoculum within the field of interest [46][47][48]. Spread resulting from diseased, alternative hosts or infested crop residues within a field may also be a likely explanation for initiation of CLS epidemics as randomly distributed foci.…”

Section: Diseases Affecting Foliar Health-cercospora Leaf Spotmentioning
confidence: 99%

“…Therefore, for CLS management, the burial of crop residue after harvest and a rotation of at least three years between susceptible crops such as processing spinach (also grown in western New York) may be beneficial. In small-scale, fresh market crops where table beet and other susceptible crops may be in close proximity, separation between crops may also be beneficial to prevent spread of conidia by wind-blown rain [47]. Studies evaluating genotypic diversity and genetic differentiation of C. beticola populations on Swiss chard and table beet in the same field have demonstrated sympatry, suggesting the absence of host differentiation and populations on either host are likely to cause disease on each other [53].…”

Section: Diseases Affecting Foliar Health-cercospora Leaf Spotmentioning
confidence: 99%

Challenges and Prospects for Building Resilient Disease Management Strategies and Tactics for the New York Table Beet Industry
Pethybridge
¹
,
Kikkert
²
,
Hanson
³

et al. 2018
Agronomy
36
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26
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Abstract:The New York table beet industry is expanding and has unique challenges to minimize crop loss in both conventional and organic production. Diseases may reduce plant population density and increase heterogeneity in a stand, reduce the duration of time foliage is healthy, and decrease the yield of marketable roots. Rhizoctonia solani Kuhn and Pythium ultimum Trow are dominant in the pathogen complex affecting crop stand and root health. Cercospora leaf spot (CLS) caused by the fungus, Cercospora beticola Sacc

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“…C. zonata is presumed to persist as fascicles of conidiophores or as dormant stromatic mycelium in crop residue remaining on the soil surface (Walker 1952;Yu 1947). The principal agents for dispersal of conidia from infested residue on the soil surface are likely to be wind and rain, which influence spatial patterns of disease distribution (de Nazareno et al 1993;Vereijssen at al. 2006;Ward et al 1999).…”

mentioning
confidence: 99%

“…Reports on dispersal of C. beticola¸the causal agent of Cercospora leaf spot on sugar beet, show that, when wind is the principal dispersal agent, spatial patterns are less distinct than when rain-splash is involved, because dissemination by wind can occur over greater distances from infected crops (Khan et al 2008;Lawrence and Meredith 1970). Dispersal of conidia by rain-splash, in contrast, resulted in decreasing incidence of Cercospora leaf spot over short distances, with infection from infested debris at the soil surface occurring first on the lower leaves and wind playing a secondary role in inoculum dispersal (McKay and Pool 1918;Vereijssen at al. 2006;Windels et al 1998).…”

mentioning
confidence: 99%

Temporal and Spatial Development of Cercospora Leaf Spot of Faba Bean Influenced by In Situ Inoculum
Kimber
¹
,
Paull
²
,
Scott
³

et al. 2016
Plant Disease
8
1
1
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The temporal and spatial dynamics of Cercospora leaf spot on susceptible and resistant lines of faba bean grown in or at defined distances from soil with residues infested by Cercospora zonata were examined in South Australia in 2005 and 2006. The disease was first observed on susceptible seedlings 49 days after sowing (DAS) in soil that had been sown with faba bean every 3 years since 1997 (positive soil zone for C. zonata) but was delayed by 1 week in adjacent soil (0 to 16 m away) with no history of cultivation of faba bean (negative soil zone). The incidence of diseased seedlings from 49 to 63 DAS showed a gradient from 4 to 16 m from the infested soil and was significantly greater for susceptible plants grown in the positive versus negative soil zones in field trials conducted in 2005 and 2006 (92 versus 30% in 2005, χ21 = 32.2, P < 0.001; 98 versus 55% in 2006, χ21 = 12.1, P < 0.001). The incidence of Cercospora leaf spot on the resistant line 1322/2 was significantly less (χ26 = 171.7; P < 0.001) than on the susceptible line ‘Farah’ at that time in both years, with fewer than 5% of the seedlings showing the disease. However, a gradient was shown at 70 to 84 DAS, where disease incidence was significantly greater on line 1322/2 in the positive soil zone than on plants in the negative soil zone in both years (62 and 18%, respectively, with χ21 = 27.9, P < 0.001 in the 2005 trial; and 47 and 6%, respectively, with χ21 = 33.3, P < 0.001 in the 2006 trial). At peak disease severity on Farah, Cercospora leaf spot mean leaf area diseased (%LAD) was severe (85 ± 4.3%) on leaves of the three nodes closest to the soil surface, and much less severe (1 ± 0.6%) in the upper canopy. Defoliation combined with %LAD was used to describe the loss of photosynthetic leaf area (%LPLA) in both cultivars, on both soil zones, in each year. Nonlinear regression analyses using a logistic model described disease development over time on susceptible plants grown in infested soil (e.g., for +12-m blocks within infested soil, y = 2.66 + 46.08/[1 + exp(−0.23 × [X − 40.92])] in 2005 and y = 0.49 + 5.02/[1 + exp(−0.14 × [X − 28.30])] in 2006, where X = DAS and y = %LPLA, with both regressions significant at P < 0.001), whereas an exponential model (e.g., for −12-m blocks from infested soil, y = 0.23 + 0.77 × 1.04X in 2005 and y = 0.44 + 0.56 × 1.04X in 2006, both at P < 0.001) best described disease gradients with increasing distance from the inoculum source. Paired t tests of %LPLA at 77 and 98 DAS showed significant differences in disease severity in the positive versus negative soil zones and a steep gradient in %LPLA from 0 to 4 m from the inoculum source. The role of infested faba bean residue in survival of C. zonata over time was also examined using a pot-bioassay and in situ field assay. When residues were removed from the soil surface or depleted rapidly by animal grazing, the amount of C. zonata inoculum in the soil was significantly less (P < 0.001) than for soil with residue remaining on the soil surface. C. zonata survived in soil and remained infective for at least 30 months after harvest of an infected faba bean crop.

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Spatial pattern of Cercospora leaf spot of sugar beet in fields in long- and recently-established areas

Cited by 15 publications

References 23 publications

Spatio-temporal patterns of pre-harvest brown rot epidemics within individual peach tree canopies

Spatio-temporal patterns of pre-harvest brown rot epidemics within individual peach tree canopies

Challenges and Prospects for Building Resilient Disease Management Strategies and Tactics for the New York Table Beet Industry

Temporal and Spatial Development of Cercospora Leaf Spot of Faba Bean Influenced by In Situ Inoculum

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