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Passive heat treatment of sweet basil crops suppresses white mould and grey mould
Author(s) -
Elad Y.,
Rav David D.,
Israeli L.,
Fogel M.
Publication year - 2017
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1111/ppa.12550
Subject(s) - sclerotinia sclerotiorum , botrytis cinerea , biology , horticulture , shoot , inoculation , microclimate , relative humidity , botany , ecology , physics , thermodynamics
Sweet basil white mould ( BWM , Sclerotinia sclerotiorum ) and grey mould ( BGM , Botrytis cinerea ) are important diseases in Israel and other basil‐growing regions. The impact of microclimate on BWM and BGM and on plant sensitivity to these diseases was studied. Disease incidence was evaluated in three field experiments, each consisting of 10–12 polyethylene‐covered tunnels. BWM and BGM incidences were correlated with air temperature, relative humidity ( RH ) and soil temperature data. The incidence of BWM was negatively correlated with high (above >25 or >30 °C) air temperatures, RH > 50% and RH > 75% and high (>21 or >24 °C) soil temperatures. BGM incidence was negatively correlated with high (>25 °C) air temperatures and high (>21 or >24 °C) soil temperatures, and positively correlated with RH >65% or >75%. Shoots harvested from plants grown in the walk‐in tunnels were inoculated with S. sclerotiorum or B. cinerea under controlled conditions. Severity of BWM and BGM on those shoots was negatively correlated with tunnel air temperatures of >25 and >30 °C and soil temperatures >18 °C. Thus, high temperatures were related to reduced disease incidence and to reduced sensitivity to the pathogens. Experiments involving potted plants revealed that heating only the root zone suppresses canopy susceptibility to BWM and BGM . These findings indicate that the effect of high greenhouse temperatures involves an indirect systemic effect that renders the host less susceptible to disease. This effect was also observed in harvested shoots that were no longer at the high temperatures, and the effect was systemic.