Evaluation of pre-harvest fungicide treatments against Alternaria rot in California mandarins and occurrence of mutations associated with fungicide resistance
Boris X. Camiletti , Paulo S.F. Lichtemberg , Yong Luo , Victor M. Gabri , Themis J. Michailides
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引用次数: 0
Abstract
This study aimed to investigate the management of Alternaria rot in citrus by evaluating the efficacy of late-season fungicide programs in reducing latent infections and fruit drop. Furthermore, the occurrence of mutations conferring resistance to QoI and SDHI fungicides within an Alternaria population isolated from citrus was investigated. In field trials, high frequencies of Alternaria infections were observed on the stem end and stylar end of Satsuma and Shiranui mandarins, with a higher prevalence of stem-end infections. Fungicide treatments applied towards the end of the season effectively reduced the frequency of latent infections on the stem end, indicating that such infections occur during this period under specific conditions. While some fungicide treatments demonstrated efficacy in reducing fruit drop caused by Alternaria rot, the results varied across different orchards and years. Latent infections on fruits persisted at high frequencies in the majority of trials, highlighting the complex nature of disease management. Mutations associated with resistance against QoI and SDHI fungicides were identified within the Alternaria population affecting California citrus. Our study suggests the potential need for fungicide sprays at the onset of the season to reduce the frequency of Alternaria infections on the stem end and stylar end of fruits. However, the observed non-correlation or low correlation between latent infections and fruit drop indicates that latent infections alone cannot reliably predict fruit drop. Our findings indicate that pre-harvest fungicide treatments have inconsistent efficacy and are cost-effective only during unpredictable disease outbreaks.
期刊介绍:
The Editors of Crop Protection especially welcome papers describing an interdisciplinary approach showing how different control strategies can be integrated into practical pest management programs, covering high and low input agricultural systems worldwide. Crop Protection particularly emphasizes the practical aspects of control in the field and for protected crops, and includes work which may lead in the near future to more effective control. The journal does not duplicate the many existing excellent biological science journals, which deal mainly with the more fundamental aspects of plant pathology, applied zoology and weed science. Crop Protection covers all practical aspects of pest, disease and weed control, including the following topics:
-Abiotic damage-
Agronomic control methods-
Assessment of pest and disease damage-
Molecular methods for the detection and assessment of pests and diseases-
Biological control-
Biorational pesticides-
Control of animal pests of world crops-
Control of diseases of crop plants caused by microorganisms-
Control of weeds and integrated management-
Economic considerations-
Effects of plant growth regulators-
Environmental benefits of reduced pesticide use-
Environmental effects of pesticides-
Epidemiology of pests and diseases in relation to control-
GM Crops, and genetic engineering applications-
Importance and control of postharvest crop losses-
Integrated control-
Interrelationships and compatibility among different control strategies-
Invasive species as they relate to implications for crop protection-
Pesticide application methods-
Pest management-
Phytobiomes for pest and disease control-
Resistance management-
Sampling and monitoring schemes for diseases, nematodes, pests and weeds.