Bragantia (2007) 66, 373-379

Eduardo Caruso Machado, Ricardo Ferraz De Oliveira, Rafael Vasconcelos Ribeiro, Camilo Lázaro Medina, Eduardo Sanches Stuchi and Luiz Carlos Pavani (2007)
Deficiência hídrica agrava os sintomas fisiológicos da clorose variegada dos citros em laranjeira 'Natal'
[Water deficiency intensifies physiological symptoms of citrus variegated clorosis in 'Natal' sweet orange plants]
Bragantia 66 (3), 373-379
Abstract: Citrus variegated chlorosis (CVC) is a disease that has caused serious economical losses in citrus grove located in the North and Northeastern regions of São Paulo State, where water deficiency and high temperature occur frequently. Therefore, the aim of this work was to evaluate the influence of water deficiency on the development of physiological symptoms in 'Natal' sweet orange plants with CVC. Measurements of leaf water potential, transpiration, stomatal conductance e CO₂ assimilation were taken in plants under natural conditions and submitted to irrigation. The experimental design was in randomized blocks, with five replications. Stomatal conductance, daily transpiration and leaf water potential were lower in CVC-affected plants. The daily CO₂ assimilation was reduced in CVC-affected plants, even in irrigated ones. In fact, irrigation decreased the negative effects of CVC, however, it did not prevent disease establishment in sweet orange plants inoculated with Xylella fastidiosa. Compared to other treatments, infected plants submitted to natural conditions (without irrigation) exhibited higher constrain of leaf gas exchange, even when measurements were taken during humid period (summer).
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): Rafael Vasconcelos Ribeiro

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Xylella fastidiosa	Citrus (genus)	Brazil (south)