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Available from: Laurence V Madden, Mar 21, 2014
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    • "Leaf density measured through the leaf area index (LAI) had an effect on the physiological barrier increasing with canopy LAI. Similar effects were observed for Colletotrichum acutatum on strawberry (Yang et al., 1990; Madden et al., 1993), suggesting that the physiological barrier effect is a major plant architectural phenomenon that influences a wide range of pathosystems. In apple trees, Tivoli et al. (2013) suggested that some trimming systems led to a higher aeration and therefore shorter periods of wetness, hence less apple scab infection (Venturia inaequalis). "
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    ABSTRACT: Downy mildew (Plasmopara viticola) and botrytis bunch rot (Botrytis cinerea) are important diseases in the highlands of Santa Catarina State, a relatively new wine-growing region in Brazil. Although it is known that training systems can affect microclimate and subsequent disease development, this has not been examined in the highlands of Brazil. Thus, the purpose of this study was to evaluate the influence of Y-trellis (YT) and vertical shoot positioning (VSP) training system on downy mildew and botrytis bunch rot disease development in ‘Cabernet Sauvignon’ cultivar. Experiments were carried out in commercial vineyards in São Joaquim, SC Municipality, southern Brazil, during the year 2012–2013 and 2013–2014 growing seasons. Downy mildew incidence and severity were quantified weekly from the first symptoms appearance on leaves and botrytis bunch rot incidence was evaluated at harvest. Disease progress curves were constructed compared according to: (a) beginning of symptoms appearance; (b) time to maximum disease incidence and severity; (c) maximum disease incidence and severity; and (d) area under the incidence and severity disease progress curve. Results showed significant differences in downy mildew and botrytis bunch rot intensity among grape training systems, where VSP training system showed significantly lower area under the incidence and severity disease progress curve and intensity of downy mildew and botrytis bunch rot in both 2012–2013 and 2013–2014 growing seasons. Collectively, the results of this study suggest VSP training system should be recommended for grapevine production to reduce both downy mildew and botrytis bunch rot in the highlands regions of southern Brazil.
    Scientia Horticulturae 03/2015; 185. DOI:10.1016/j.scienta.2015.01.023 · 1.50 Impact Factor
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    • "These results were explained by opposite effects: the direct effect of low canopy porosity favouring ascospore dispersal and disease development , and the indirect effect of larger LAI on the microclimate, increasing the wetness duration and disease severity (Le May et al. 2008). Similar effects on spore dispersal were observed in Colletotrichum acutatum on strawberry, a crop with a canopy structure very different from that of pea (Yang et al. 1990; Madden et al. 1993) and in Mycosphaerella graminicola on wheat in field conditions (Lovell et al. 1997). "
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    • "These results were explained by opposite effects: the direct effect of low canopy porosity favouring ascospore dispersal and disease development , and the indirect effect of larger LAI on the microclimate, increasing the wetness duration and disease severity (Le May et al. 2008). Similar effects on spore dispersal were observed in Colletotrichum acutatum on strawberry, a crop with a canopy structure very different from that of pea (Yang et al. 1990; Madden et al. 1993) and in Mycosphaerella graminicola on wheat in field conditions (Lovell et al. 1997). "
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    ABSTRACT: As any epidemic on plants is driven by the amount of susceptible tissue, and the distance between organs, any modification in the host population, whether quantitative or qualitative, can have an impact on the epidemic dynamics. In this paper we examine using examples described in the literature, the features of the host plant and the use of crop management which are likely to decrease diseases. We list the pathogen processes that can be affected by crop growth and architecture modifications and then deter-mine how we can highlight the principal ones. In most cases, a reduction in plant growth combined with an increase in plant or crop porosity reduces infection efficiency and spore dispersal. Experimental approaches in semi-controlled conditions, with con-comitant characterisation of the host, microclimate and disease, allow a better understanding and analysis of the processes impacted. Afterwards, the models able to measure and predict the effect of plant growth and architecture on epidemic behaviour are reviewed.
    European Journal of Plant Pathology 10/2012; 135(3). DOI:10.1007/s10658-012-0111-5 · 1.71 Impact Factor
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