Epidemics of coffee leaf rust (CLR), caused by the biotrophic fungus Hemileia vastatrix, contribute to lower production of fruit berries. This study aimed to determine the potential of Mantus® [nitrogen (1%) and copper (20%) complexed with a plant-derived pool of polyphenols (10%) and referred to as copper-polyphenols compound (CPC) hereafter] to hamper the infection process of H. vastatrix in coffee leaves. A 3 × 2 factorial experiment was arranged in a completely randomized design with four replications (one plant) per evaluation time. The factors studied were plants sprayed with water (control), CPC (1 mL/L), and fungicide (dicopper chloride trihydroxide) that were non-inoculated or inoculated with H. vastatrix. Some components of coffee resistance against infection by H. vastatrix [incubation period (IP, in days), latent period (LP, in days), intensity of fungal sporulation (IFS), area of uredosporic sori (AUS), number of uredosporic sori (NUS) per cm2 of leaf, and production of urediniospores (PU) per cm2 of leaf] and impairments in photosynthesis [quantification of the parameter maximum photochemical efficiency of photosystem II (Fv/Fm) and the pool of photosynthetic pigments] were determined in the plants of each treatment. In the in vitro assay, urediniospores germination was significantly reduced by 59 and 99% for the CPC and fungicide treatments, respectively, compared to the control treatment. Urediniospores did not germinate after exposure to 2.5, 5, 10, and 15 mL of CPC/L. The CLR severity (92-99% from 22 to 35 days after inoculation) and the area under coffee leaf rust progress curve (98 to 99%) were significantly lower for plants from CPC and fungicide treatments compared to plants from the control treatment. The IP significantly increased by 46 and 53% for CPC and fungicide treatments, respectively, compared to the control treatment. The LP and the IFS were significantly higher by 40% and lower by 55%, respectively, for CPC treatment compared to the control treatment. For the CPC treatment, significant decreases of 28 and 45% were obtained for the AUS and the NUS, respectively, compared to the control treatment. The PU was significantly lower by 96 and 99% for CPC and fungicide treatments, respectively, compared to the control treatment. At the physiological level, the CPC-sprayed and infected plants displayed a better photosynthetic performance based on the greatest values for Fv/Fm linked to the preservation of chlorophyll a+b and carotenoids concentrations compared to water-sprayed and infected ones. In conclusion, the CPC showed great potential to affect the infection process of H. vastatrix, considering that some components of coffee resistance were greatly affected. It is noteworthy in this context that besides the effect of Cu from the CPC against the germination of urediniospores from H. vastatrix, defense reactions could be boosted in coffee leaves to hamper the colonization of leaf tissues by fungal hyphae. Considering a field coffee-growing scenario, using CPC could contribute to lowering the CLR epidemic rate and be considered in an integrated disease management program.

A copper-polyphenols compound hampers the infection process of Hemileia vastatrix on coffee leaves

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发表日期：

2025年3月21日

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Henara Valéria Miranda Castro,
Verônica Vieira Brás,
Leandro Castro Silva,
Isabela Maria Grossi Leal,
Leonardo Packer Quadros,
Fabrício Ávila Rodrigues

摘要

Epidemics of coffee leaf rust (CLR), caused by the biotrophic fungus Hemileia vastatrix, contribute to lower production of fruit berries. This study aimed to determine the potential of Mantus^® [nitrogen (1%) and copper (20%) complexed with a plant-derived pool of polyphenols (10%) and referred to as copper-polyphenols compound (CPC) hereafter] to hamper the infection process of H. vastatrix in coffee leaves. A 3 × 2 factorial experiment was arranged in a completely randomized design with four replications (one plant) per evaluation time. The factors studied were plants sprayed with water (control), CPC (1 mL/L), and fungicide (dicopper chloride trihydroxide) that were non-inoculated or inoculated with H. vastatrix. Some components of coffee resistance against infection by H. vastatrix [incubation period (IP, in days), latent period (LP, in days), intensity of fungal sporulation (IFS), area of uredosporic sori (AUS), number of uredosporic sori (NUS) per cm² of leaf, and production of urediniospores (PU) per cm² of leaf] and impairments in photosynthesis [quantification of the parameter maximum photochemical efficiency of photosystem II (F_v/F_m) and the pool of photosynthetic pigments] were determined in the plants of each treatment. In the in vitro assay, urediniospores germination was significantly reduced by 59 and 99% for the CPC and fungicide treatments, respectively, compared to the control treatment. Urediniospores did not germinate after exposure to 2.5, 5, 10, and 15 mL of CPC/L. The CLR severity (92-99% from 22 to 35 days after inoculation) and the area under coffee leaf rust progress curve (98 to 99%) were significantly lower for plants from CPC and fungicide treatments compared to plants from the control treatment. The IP significantly increased by 46 and 53% for CPC and fungicide treatments, respectively, compared to the control treatment. The LP and the IFS were significantly higher by 40% and lower by 55%, respectively, for CPC treatment compared to the control treatment. For the CPC treatment, significant decreases of 28 and 45% were obtained for the AUS and the NUS, respectively, compared to the control treatment. The PU was significantly lower by 96 and 99% for CPC and fungicide treatments, respectively, compared to the control treatment. At the physiological level, the CPC-sprayed and infected plants displayed a better photosynthetic performance based on the greatest values for F_v/F_m linked to the preservation of chlorophyll a+b and carotenoids concentrations compared to water-sprayed and infected ones. In conclusion, the CPC showed great potential to affect the infection process of H. vastatrix, considering that some components of coffee resistance were greatly affected. It is noteworthy in this context that besides the effect of Cu from the CPC against the germination of urediniospores from H. vastatrix, defense reactions could be boosted in coffee leaves to hamper the colonization of leaf tissues by fungal hyphae. Considering a field coffee-growing scenario, using CPC could contribute to lowering the CLR epidemic rate and be considered in an integrated disease management program.