Pest Management Science (2014) 70, 415-426

Philip A. Stansly, H. Alejandro Arevalo, Jawwad A. Qureshi, Moneen M. Jones, Katherine Hendricks, Pamela D. Roberts and Fritz M. Roka (2014)
Vector control and foliar nutrition to maintain economic sustainability of bearing citrus in Florida groves affected by huanglongbing
Pest Management Science 70 (3), 415-426
Abstract:
BACKGROUND
Huanglongbing (HLB) or citrus greening is a bacterial disease vectored by the Asian citrus psyllid (ACP) causing tree decline, and yield loss. Vector control and foliar nutrition are used in Florida to slow the spread of HLB and mitigate debilitating effects of the disease.
A four year replicated field study was initiated February 2008 in a 5.2-ha commercial block of young 'Valencia' orange trees employing a factorial design to evaluate individual and compound effects of vector management and foliar nutrition. Insecticides were sprayed during tree dormancy and when psyllid populations exceeded a nominal threshold. A mixture consisting primarily of micro- and macro-nutrients was applied three times a year corresponding to the principal foliar flushes.
RESULTS
Differences in ACP numbers from five- to 13-fold were maintained in insecticide treated and untreated plots. Incidence of HLB estimated by polymerase chain reaction (PCR), rose from 30% at the beginning of the study to 95% in only 18 months. Highest yields all four years were seen from trees receiving both foliar nutrition and vector control. Production for these trees in the fourth year was close to the pre-HLB regional average for 10 year old 'Valencia' on 'Swingle'. Nevertheless, at current juice prices, the extra revenue generated from the combined insecticide and nutritional treatment did not cover the added treatment costs.
CONCLUSIONS
This experiment demonstrated that vector control, especially when combined with enhanced foliar nutrition, could significantly increase yields in a citrus orchard with high incidence of HLB. Economic thresholds for both insecticide and nutrient applications are needed under different market and environmental conditions.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Philip A. Stansly, Jawwad A. Qureshi

Research topic(s) for pests/diseases/weeds:
control - general
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Liberibacter asiaticus	Citrus (genus)	U.S.A. (SE)
	Diaphorina citri	Citrus (genus)	U.S.A. (SE)