Influence of temperature and leaf wetness duration in the severity of Cercospora leaf spot of beet

Leandro Luiz Marcuzzo,Aline Nacimento,Roberto Haveroth

doi:10.1590/0100-5405/2111

Leandro Luiz Marcuzzo, Aline Nacimento + Show 1 more

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https://doi.org/10.1590/0100-5405/2111

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Journal: Summa Phytopathologica	Publication Date: Mar 1, 2016
Citations: 2	License type: cc-by

Affiliation: Instituto Federal Catarinense

Abstract

ABSTRACT In the present study, the influence of temperature (15, 20, 25, 30 and 35°C) and leaf wetness period (6, 12, 24 and 48 hours) on the severity of Cercospora leaf spot of beet, caused by Cercospora beticola, was studied under controlled conditions. Lesion density was influenced by temperature and leaf wetness duration (P<0.05). Data were subjected to nonlinear regression analysis. The generalized beta function was used for fitting the disease severity and temperature data, while a logistic function was chosen to represent the effect of leaf wetness on the severity of Cercospora leaf spot. The response surface resultant of the product of the two functions was expressed as ES = 0.0001105 * (((x-8)2.294387) * ((36-x)0.955017)) * (0.39219/(1+25.93072 * exp (-0.16704*y))), where: ES represents the estimated severity value (0.1); x, the temperature (ºC) and y, the leaf wetness duration (hours). This model should be validated under field conditions to assess its use as a computational forecast system for Cercospora leaf spot of beet.

Highlights

In the present study, the influence of temperature (15, 20, 25, 30 and 35°C) and leaf wetness period (6, 12, 24 and 48 hours) on the severity of Cercospora leaf spot of beet, caused by Cercospora beticola, was studied under controlled conditions
Chemical control is available, Cercospora leaf spot normally precludes the commercialization of packed plants due to the presence of diseased and senescent leaves [6, 9]
The aim of this study was to establish the relationship between different temperature values and leaf wetness duration on the severity of Cercospora leaf spot of beet

Summary

Introduction

The influence of temperature (15, 20, 25, 30 and 35°C) and leaf wetness period (6, 12, 24 and 48 hours) on the severity of Cercospora leaf spot of beet, caused by Cercospora beticola, was studied under controlled conditions. Influência da temperatura e da duração do molhamento foliar na severidade da cercosporiose da beterraba. No presente trabalho foram estudadas, em condições controladas, a influência da temperatura (15, 20, 25, 30 e 35°C) e do molhamento foliar (6, 12, 24 e 48 horas) na severidade da cercosporiose da beterraba causada por Cercospora beticola.

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