The average incidence of HLB rose from 22.37% in 2021 to 24.42% in 2022 in Brazil’s citrus belt, an annual survey by Fundecitrus shows. That’s an increase of 9.16%.
In the regions of Brotas, Limeira and Porto Ferreira, where the incidence was already high in previous years, HLB increased to even more worrying levels of 49.41%, 70.72% and 74.05%, respectively. HLB is also commonly called greening disease.
“We are seeing the disease grow at a worrying speed,” said Fundecitrus General Manager Juliano Ayres. “However … the results obtained in properties in regions that have registered a decline or stabilization of the disease reinforce our confidence that the measures to combat greening are effective. This has always been the way and always will be, until we manage to reach plants resistant to the disease. However, we need more efforts” to control HLB.
REASONS FOR HLB INCREASE
Fundecitrus reported that most regions have a favorable climate for HLB. Additionally, most regions have a high density of orchards and a large number of medium and small properties. Those factors make it difficult to coordinate joint actions for the regional management of the disease.
Most importantly though, Fundecitrus stated, in most orchards in production, diseased trees are not being eliminated, and control of HLB-spreading psyllids has been inadequate. Inefficient spraying has also contributed to the increase in HLB.
“This work has not been done with the necessary frequency, especially in the sprouting seasons,” said Fundecitrus researcher Renato Bassanezi. “Failures in spray coverage have also been observed, mainly at the top of the canopy of adult trees and in dense orchards.”
Also impairing the effectiveness of psyllid control is the repetitive use of insecticides from the pyrethroid group without adequate rotation with insecticides with other modes of action, Fundecitrus stated. That has led to the detection of psyllid resistance to the pyrethroid group in some places.
BIG JUMP IN CANKER
The Fundecitrus survey also showed growth in the incidence of canker in orchards. According to the new survey, the disease is present in 18.77% of the trees, an increase of 74.44%.
Canker accounts for just 0.21% of fruit drop across the citrus belt. The low rate is related to studies carried out by Fundecitrus that adjust the use of copper in the management of the disease. That adjustment doesn’t impact the effectiveness of the treatment and generates savings of 56% in the amount of product used per hectare.
CVC REMAINS LOW
The incidence of CVC remains low throughout Brazil’s citrus industry, with an incidence of just 0.80% in 2022. About 20 years ago, the disease was present in 46% of the trees. The significant reduction is mainly due to the evolution of research and management practices disseminated by Fundecitrus.
Source: Fundecitrus
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