African Tulip Tree
in Fiji and its presence in Central America
African Tulip Tree (ATT) has become a very serious problem in Fiji. In this context, the authorities of Fiji requested technical assistance to FAO in order to control the plant and to prevent its further spread.
FAO Technical cooperation implemented a project in 1999, where main activities were a national survey to identify the magnitude of the problem posed by ATT, studies on the biology of the plant, training on biocontrol, study tour of two national specialists to Africa and formulation of a long-term project for the control of the tree.
As a epilogue of the project a national workshop on the control of African Tulip Tree (ATT) was held from 29 to 31 March 2000. The programme of the workshop discussed:
- Remedial measures for the control of ATT.
- Results of the survey of the plant distribution in Viti Levu island and conducted
- Studies on competition and ecobiology of the treE.
- Results of the study tour to Africa (South Africa and Kenya)
- Draft of the project document prepared by the international expert
Conducted survey clearly indicated that ATT is well distributed in Fiji, but it is not found in forest of pines, sugarcane plantations and pastures. Most of the information given in the workshop about the control and infestation of the tree was coming from areas of Fijian farmers, who regularly have up to 30 acres of land, but cultivate only 10-15% of it every year. Unoccupied spaces are invaded by ATT. No data was provided from Chinese farmers, who rent the land for periods of up to five years and effectively eliminate the tree. The Fijians consider that these control practices should not be taken into consideration because the Chinese farmers exhaust soil fertility in the period of leasing.
The studies on the biology of the trees, conducted with the support of FAO showed that this plant grows and spreads quickly through seed and runners reproduction. Seeds germinate in two weeks after falling into the soil and short runners germinate faster than long ones.
The study tour in Africa gave good information about the procedures for the introduction of exotic biological control agent in Fiji. It was also noted that an Eryophid insect seems to be a potential candidate as a biocontrol agent against ATT.
Conducted chemical control trials have indicated the effectiveness of the use of 2,4 D + Dicamba and glyphosate applied over the cut stump of the tree or in the ring bark . The latter alone is effective for killing the upper part of the tree, but runners and subterranean part of the plant remain healthy with this procedure. These methods of chemical control of ATT in Fiji will form only a part of the integrated control system required to manage this species.
Invasion of the tree is particularly likely to take place after cyclone damage but could occur at any time. Replacement of native tree species by ATT is having a profound effect on the biodiversity of the forests as many native trees carry extensive tree - dependent flora of epiphytes and vines.
Because of the difficulties experienced by farmers in controlling ATT infestations they had tended to leave these areas in clear more natural forests. This is resulting in further incursion by ATT into natural forests.
It is envisaged that an Integrated Control Programme be developed, which will include, classical biological control, crop rotation, selective chemical control in crops and use of mulches both as living intercrops and dead plant material. In addition, utilisation of large trees will be investigated.
An awareness campaign amongst farmers and the wider community is also required to stop deliberate planting of the tree and to remove young plants before they flower and spread seed. The workshop recommended to launch an active campaign of awareness for the control of the tree.
In addition, there is no Inter-island quarantine legislation yet in place, categorizing the tree as a pest in order to prevent its spread to non-infested islands in Fiji. This needs to be strengthened with further advice warning the current use of the tree as living fence posts and planting as an ornamental.
The first draft of a project, prepared by the international consultant and revised by FAO, foresees the development of a research programme in biocontrol of the tree and the implementation of other control methods, including the work with farmers.
The plant is already a problem in coffee plantations of central part of Cuba and is spreading fast in some other Central American countries as Costa Rica and Guatemala. If this dispersal is not stopped prohibiting its reproduction and planting, these countries will face the same problem as it is seen in Fiji now.
Information updated by R. Labrada, FAO Weed Officer(18 July 2006).