QUALITATIVE APPROACH FOR MODELING OUTBREAKS OF GRAY MOLD EPIDEMICS INNONHEATED CUCUMBER GREENHOUSES

Citation
H. Yunis et al., QUALITATIVE APPROACH FOR MODELING OUTBREAKS OF GRAY MOLD EPIDEMICS INNONHEATED CUCUMBER GREENHOUSES, Crop protection, 13(2), 1994, pp. 99-104
Citations number
14
Categorie Soggetti
Agriculture
Journal title
ISSN journal
02612194
Volume
13
Issue
2
Year of publication
1994
Pages
99 - 104
Database
ISI
SICI code
0261-2194(1994)13:2<99:QAFMOO>2.0.ZU;2-L
Abstract
Disease records and microclimatic parameters were analysed in order to develop a model for predicting outbreaks of grey mould (Botrytis cine rea) epidemics in non-heated cucumber greenhouses. A quantitative stat istical approach failed to produce a reliable model. However, when emp loying a qualitative approach, an accurate, biologically sound predict ion model was developed. Outbreaks of grey mould occurred when, on a w eekly average, the wetting period of the foliage exceeded 7 h day-1 an d the duration of temperature in the range of 9-21-degrees-C during th e night (18:00-08:00) exceeded 9.5 h day-1. Data recorded in two growi ng seasons were used to construct the model and its predictions were e valuated with an independent data set. Controlled-environment experime nts provided biological interpretations for these greenhouse-originate d thresholds: when free moisture was present, germination of B. cinere a spores occurred within 7 h; the period during which the pathogen is exposed to environmental microclimatic influences (germination and pen etration) is 9-10 h. The potential for outbreaks of grey mould epidemi cs in commercial greenhouses could be reduced by restricting the wetti ng period to <7 h day-1 by measures such as ventilation and heating.