South American leaf blight of Hevea brasiliensis: spore dispersal of Microcyclus ulei

Production of rubber from Hevea brasiliensis (Willd. ex A. Juss) Muell.-Arg. (Euphorbiaceae) is greatest in southeastern Asia where the South American leaf blight disease is absent. Except for the Pacific Piedmont of Guatemala, plantation production in the Americas is limited severely by the now widespread presence of the pathogen Microcyclus ulei (P. Henn.) Arx. Mean latex yields from trees growing on the Piedmont approximate those of Indonesia and Malaysia, with little evidence of damage from leaf blight. The scope and scale of the Guatemalan anomaly suggest that environmentally modulated escape rather than previously assumed disease resistance may be the key to successful production of natural rubber in this hemisphere. The Guatemalan industry is presently well-organized to service regional markets in Mexico and the Caribbean Basin. Given due attention to environmental analysis, it may serve also as a model for the development of regional production facilities in other parts of tropical America.

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Microcyclus ulei races in Brazil

Summa Phytopathologica ◽

10.1590/0100-5405/172339 ◽

2017 ◽

Vol 43 (4) ◽

pp. 326-336 ◽

Cited By ~ 1

Author(s):

João Alberto Zago Bevenuto ◽

José Raimundo de Souza Passos ◽

Edson Luiz Furtado

Keyword(s):

Cluster Analysis ◽

Causative Agent ◽

Hevea Brasiliensis ◽

Binary Data ◽

Leaf Blight ◽

Centroid Method ◽

Microcyclus Ulei

ABSTRACT The fungus Microcyclus ulei is the causative agent of leaf blight in rubber trees, which is one of the most important diseases affecting this crop, since it causes intense defoliation. Several races of this pathogen have been described in Brazil based on a series of diverse differential clones. According to the reactions of 11 differential clones already reported in the literature (MDF 180, Fx 3844, Fx 985, Fx 4098, Fx 2261, Fx 2804, Fx 3899, IAN 6158, IAN 3087, IAN 717 and PA 31), containing the species Hevea brasiliensis. Hevea benthamiana and Hevea pauciflora, a cluster analysis of the binary data referring to virulence of this disease was performed by using the Jaccard method. The cluster analysis was fitted according to the centroid method. Results indicated the existence of 53 different races of this pathogen in Brazil.

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Assessment of rubber tree panels under crowns resistant to South American leaf blight

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2011000500003 ◽

2011 ◽

Vol 46 (5) ◽

pp. 466-473 ◽

Cited By ~ 4

Author(s):

Larissa Alexandra Cardoso Moraes ◽

Adônis Moreira ◽

José Roberto Antoniol Fontes ◽

Everton Rabelo Cordeiro ◽

Vicente Haroldo de Figueiredo Moraes

Keyword(s):

Nutritional Status ◽

Rubber Tree ◽

Leaf Blight ◽

Physiological Characteristics ◽

Yield Potential ◽

South American ◽

Efficient Technology ◽

Simultaneous Evaluation ◽

Microcyclus Ulei ◽

Selection Of

The objective of this work was to assess the performance of panel clones under crowns resistant to South American leaf blight (Microcyclus ulei). The experiment was carried out with 18 panel clones crown-budded with Hevea pauciflora x H. guianensis, in a Xanthic Ferralsol (Oxisol) in Manaus, AM, Brazil. The following parameters were evaluated: dry rubber yield, plant nutritional status, and anatomical and physiological characteristics of the latex vessels. In the first three years of evaluation, the panel clones IAN 2878, IAN 2903, CNS AM 7905, CNS AM 7905 P1, and PB 28/59 showed the highest dry rubber yield potential, while the clones IAN 6158, IAN 6590, and IAN 6515 should not be recommended for crown budding. Higher potassium and copper foliar content in panel clones were associated to an increase in dry rubber yield. The simultaneous evaluation of anatomical and physiological characteristics of latex is fundamental for the selection of panel clones in the Amazon region. Crown budding is an efficient technology for South American leaf blight management in endemic regions.

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