Dieback of mango trees in the state of Piauí. Current situation and recommendations for control.
Viana F. M. P., Silva P. H. S. da
Author Affiliation: Eng.-Agr., D.Sc., Embrapa - Centro Nacional de Pesquisa de Agroindústria Tropical, Rua Dra. Sara Mesquita 2270, Planalto Pici, CEP 605115-110 Fortaleza, Ceará, Brazil.
Circular Técnica - Embrapa Meio-Norte : 12 pp.
Abstract : Drying of thin branches of mango trees or of whole trees caused by infections of aerial parts or roots, respectively, was observed in 1998 and 1999 in the state of Piauí, Brazil. Hypocryphalus mangiferae was associated with dieback, previously also found to be responsible for dieback of mango plantations in São Paulo causing significant economic losses. Information is included on 2 forms of disease development, i.e. the 1st one starting from H. mangiferae attacks of thin branches of trees leaving small wholes in branches, subsequently colonized by fungi. The 2nd form starts from infection of roots caused by fungi penetrating roots through wounds of different origins, especially those caused by insects. Fungi associated with dieback were identified as Ceratocystis fimbriata and Thielaviopsis paradoxa [C. paradoxa]. Strategies of disease control are outlined, including use of parathion-methyl for insect control, and preventive control through pruning of diseased branches at first appearance of disease symptoms, disinfection of pruning tools with a sodium hypochlorite solution and use of carbaryl for prevention of plant reinfestation by insects. Use of resistant cultivars is also recommended for prevention of disease. It is recommended to replace the susceptible cv. Haden by resistant cultivars Rosa, Kent, Sensation, Sabina, Oliveira Neto and Irwin.