Vanilla Diseases
The occurrence of diseases is one of the main constraints in vanilla cultivation. The important diseases are stem rot (Fusarium oxysporum f. sp. vanillae), shoot rot (Phytophthora capsici), Sclerotium rot (Sclerotium rolfsii), and anthracnose (Colletotrichum gloeosporioides); stem rot being the most devastating disease. Since a significant degree of host resistance to stem rot is not available at present, crop losses are severe under poor management. Although F. oxysporum f. sp. vanillae is a soilborne pathogen, it is also transmitted via water splash. Two types of dispersal propagules are produced; the macroconidia and the microconidia, which can easily adhere to plant parts, insects, and farming implements (Tombe et al., 1992). The disease is highly infectious and has the ability to spread rapidly and devastate extensive production areas. The disease may attack every vegetative part of the vanilla plant, although it is mostly found on the stem. Under adverse environmental conditions, the fungus produces chlamydospores for long-term survival in the soil and host debris. The pathogen can also survive within the stem without showing any symptoms.
Owing to the general poor performance of the plants and the adverse conditions, which may predispose a variety of diseases, farmers commonly abandon their farms after 5–7 years. For as long as disease-tolerant varieties or other effective control measures are unavailable, the development and production of vanilla in Indonesia remain stymied to a great extent.
Recent research indicates that successful management of stem rot can be achieved by applying the Bio-FOB approach (Tombe, 2008). This approach involves three components, which are detailed in Chapter 8. In brief, the technique consists of:
1. Planting disease-free cuttings tolerant to stem rot such as Bio-FOB vanilla cuttings (produced using nonpathogenic strains of Fusarium oxysporum).
2. Using selected bio-control agent and organic matter: Bacillus pantothenticus and Trichoderma lactae have been shown to be antagonistic to F. oxysporum f. sp. vanillae. These microbes decompose organic matter as well as have growth-promoting effects on the plant (Tombe, 2008). These two microbes are formulated under the name Bio-TRIBA. Bio-TRIBA can be mixed with compost or manure at a dosage of 2–3 L Bio-TRIBA/ton compost or manure and incubated for 1–2 weeks before application. Bio-TRIBA can also be applied by drenching onto the roots of vanilla at a dosage of 5–10 mL Bio-TRIBA/L water, preferably after the application of organic fertilizers.
3. Applying the botanical fungicide Mitol 20 EC at a concentration of 3–5 mL/L water. The formula contains active ingredients of eugenol extracted from cloves (Tombe et al., 1993; Sukamto et al., 1996) and demonstrated to be antagonistic to several plant pathogens, including F. oxysporum f. sp. vanillae.
Taking into account the proper climatic and soil conditions, using the best genetic source available, and implementing root and stem rot disease control strategies, the production and quality of vanilla in Indonesia are expected to increase.
Future Perspectives
Despite the many challenges ahead in developing and improving the production of vanilla in Indonesia, there are nevertheless advantages and sufficient optimism in the country toward ultimately achieving the status of the world’s primary producer and exporter of vanilla (Directorate General of Estate Crops, 2008). Indonesia is rich in both human and natural resources, the latter in terms of the availability of suitable land for the expansion of vanilla cultivation. The technology is available for overcoming the most significant production constraint, stem rot, based on an integrated disease management approach, the BioFOB strategy. However, extensive knowledge transfer to production areas and technology adoption by farmers need to be signifi-cantly improved (Rosman, 2005). A greater emphasis needs to be placed on the promotion of Indonesian vanilla on the international platform (Directorate General of Estate Crops, 2008). This should be in concert with the establishment of integrative domestic institutions for farmers, entrepreneurs, researchers, and the government to promote farmer knowledge, protection of farmer welfare, and communication among the sectors involved.
References
Anonymous. 1993. Study on the Trade of Vanilla Bean in the Region of Japanese Market. Department of Trade, Board of National Economic Development, 40pp. (in Indonesian).
Asnawi, R. and Y. Nuryani. 1995. Germplasm of Vanilla. Proceedings of the Agronomic Status and Post Harvest in Lampung. Bandar, Lampung, March 15th, 1995. Research Institute for Spices and Medicinal Crops, 59–68 (in Indonesian, English Abstract).
Board of National Export Development. 1995. Export development, prospect and constraint of Vanilla commodity. Proceedings of the Agronomic Status and Post Harvest in Lampung. Bandar, Lampung, March 15th, 1995. Research Institute for Spices and Medicinal Crops, 1–3 (in Indonesian).
Deinum, H.K. 1949. Vanille. In: C.J.J. van Hall and C. Van de Koppel, eds. De Landbouw in de Indische Arschiepel. II B. Uitgeverij W. Van Hoeve, Nederland, 763–784.
Directorate General of Estate Crops. 1995. Strategy and Development Program of Vanilla in Indonesia. Proceedings of the Agronomic Status and Post Harvest in Lampung. Bandar, Lampung, March 15th, 1995. Research Institute for Spices and Medicinal Crops, 15–21 (in Indonesian, English Abstract).
Directorate General of Estate Crops. 2008. Vanilla Prospects in Indonesia. Ministry of Agriculture, Jakarta, Indonesia. http://ditjenbun.deptan.go.id/rempahbun/rempah//index. php?option=com_content&task=view&id=101&Itemid=26 (Accessed May 17, 2009. In Indonesian).