Use of cover crops such as Centrosema pubescens Benth., Pueraria phaseoloides (Roxb.) Benth. Calopogonium muconoides Desv., Desmodium ovalifolium Guill. & Perr. and Tephrosia purpurea (L.) have been recommended to prevent or reduce the incidence of C. odorata in plantation crops. In the southern part of China, use of the pasture grass, Brachiaria decumbens Stapf has been reported to reduce the infestation of the pastures by C. odorata.
Chemical control using herbicides applied at the seedling stage or on early regrowth has given encouraging results. Triclopyr has proven to be the most effective. However, problems in herbicide use include (a) the high cost of the chemicals and their application, (b) ecological concerns and, (c) non-compatibility in many cropping and other environmental situations.
Biological control is a promising method that has been vigorously pursued by various organizations in the world to tackle this weed. The plant's natural enemy (Pareuchaetes pseudoinsulata Rego Barros (Lepidoptera:Arctiidae) introduced and established in Guam, Rota, Tinian, Saipan and Pohnpei has given encouraging results in suppressing this weed. This insect is currently reared in Yap, Belau, Kosrae, Indonesia, South Africa, Ghana and Ivory Coast for field establishment. Other natural enemies currently being investigated are Mescinia parvula (Zeller) (Lepidoptera: Pyralidae), Pareuchaetes aurata, Pareuchaetes insulata (Walker) (Lepidoptera: Arctiidae), Actinote anteasDoubleday (Lepidoptera: Acraeidae). Rhodobaenus cariniventris Champ.(Coleoptera:Curculionidae) and the fungal pathogens Septoria ekmaniana Petrack & Cif. (Deuteromycotina: Coelomycetes) and Cionothrix praelonga Wint. (Arthur) (Basidiomycotina: Uredinales.
The most effective biocontrol has been obtained with the release of Pareuchaetes pseudoinsulata in Guam. The best results are achieved with the release of 500 moths or 2000 larvae. Release should be done repeteadly. It is preferable o release the insect at night.
C. odorata is a problem in pasture lands, disturbed forests, roadsides, waste lands, fence rows, river banks, reserve forests, plantations of coffee, tea, teak, rubber, cocoa, oil palm, citrus, cashew, coconut and fields of rice, cotton, sugarcane, tobacco.
C. odorata is a native of tropical central and south America. It was introduced to Asia in the middle of the 1800s, to Africa in 1937 and to Micronesia in the 1960s.
Countries: Benin, Central African Republic, Cameroon, Côte d'Ivoire, Ghana, Indonesia, Papua New Guinea, Thailand, Vietnam
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