Application and validation of an Integrated control Protocol (ICP) to mitigate ink disease of chestnut (Castanea sativa Mill.)
Author(s)
Franceschini, Selma
Date Issued
May 31, 2011
Type
Doctoral Thesis
Abstract
This thesis aims to individuate an Integrated Control Protocol (ICP) to mitigate the effect of ink disease of sweet chestnut, one of the major threats of the cultivation of Castanea sativa in Italy as well as in Europe.
Three experimental areas differing for soil type, elevation, extension and management practices were individuated on the Latium and Marche regions where fields surveys were carried out from 2008 to 2010.
The ICP consisted on a series of preventive and curative measures. Preventive measures were represented by water-flow channeling, roads maintenance, restriction of human and machinery transit within affected orchard and information of chestnut owner and operators. Curative measures included metalaxyl treatments for symptomatic and diseased plants and copper-sulphate for dead plants, roads and channels. K-phosphite injections were adopted for symptomatic and asymptomatic trees to increase their resistance.
The ICP was applied in each area within a treated plots maintaining an untreated one as control. For one site ICP consisted in only K-phosphite injections.
The efficacy of treatments was assessed through the evaluation and comparison of both crown symptoms and Phytophthoras living inoculum monitoring in treated and untreated plots.
Results demonstrated that the adoption of an integrated approach allow an appreciable disease control beginning from the first year from the ICP application even though the efficacy of ICP seemed to be related with the initial disease severity being more effective for the un-heavily affected site.
K-phosphite injections revealed to be effective in decreasing crown symptoms but did not affect significantly P. cambivora inoculum in soil. On the contrary the pathogen was efficiently controlled in the trees rhizosphere and rural roads where also fungicides were applied.
The possibility to induce metalaxyl resistance in P. cambivora was investigated and ascertained through in vitro assays restricting the possibility to use the fungicide to one rather than two consecutive times hypothesized, focusing moreover the attention on the importance of preventive measures adoption.
An additional result consisted in the development of an improved and sensitive isolation technique for the detection of Phytophthora inoculum in chestnut soil samples which was indeed adopted to screen the presence and abundance of species aiming firstly to assess the effect of treatments on pathogen resident population during the time of the experimentation. Therefore the occurrence of soilborne Phytophthora in a heterogeneous landscape was investigated leading to the characterization of a diverse population composed of eleven species among which some already detected species and some not recovered before in Italy and /or Europe. The detection newly introduced Phytophthora species together with their accumulation on rural paths is consistent with a strong anthropic pressure on these agro-forest ecosystems.
Additional information
Dottorato di ricerca in Protezione delle piante
Subjects
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