Botryodiplodia sp. - Crops for the Future

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Rambutan trees are either dioecious or monoecious with male or hermaphrodite flowers and need cross pollination for fruit set. The petal-less flowers are very inconspicuous because of their tiny size (2.5 to 5 mm) and their greenish colour. They are growing on long shafted and much branched, to 30 cm long panicles and have a sweet smelling fragrance. The fruit is maturing in 15 to 18 weeks after flowering and gets an ovoid, round or ellipsoid shape with a pinkish-red, bright- or deep-red, orange-red, maroon or dark-purple, yellowishred or yellowish colour (Figure 4). The size of the rambutan fruit varies from 3.4 to 8 cm (BAERTELS, 1990, FRANKE, 1994 and MORTON, 1987a). The fruit has a thin parchment like rind with tubercles from each of which extends a soft spine. These hairy spines are 0.5 to 2 cm long and have a red, pinkish or greenish-yellow colour (Figure 5). Figure 4: Different shapes of the rambutan fruit: 1) oval, 2) ovoid and 3) ellipsoid (IPGRI, 2003) Figure 5: The most important rambutan varieties in Sri Lanka: `Malwana Special´, `Malaysian Yellow´ and `Malaysian Red The white or rose-tinted and translucent 0.4 to 0.8 cm thick flesh is very juicy and covers one ovoid to oblong almond-shaped dark seed which is 2.5 to 3.5 cm long and 1 to 1.5 cm wide. Rambutan fruits have an exotic aroma which results out of the interaction of fruity-sweet and fatty-green odours, with the possible contribution of civet-like sweetish, spicy and woody notes (ONG, ACREE and LAVIN, 1998). 12
6.1.2 Main diseases The most important yield reducing factor in rambutan plantations are birds and flying foxes and some other non flying mammals that consume many of the fruits (MORTON, 1987a). According to MORTON (1987a) the major pests are leaf eating insects like the mealy bug (Pseudococcus lilacinus) and the giant bug (Tessaratoma longicorne). The Oriental fruit fly attacks very ripe fruits and counts, according to FRANKE (1994), to the most important pests. There are several pathogens that attack the fruit and cause rotting under warm and moist conditions, like Botryodiplodia sp. which was mentioned before. These fungi are important post harvest diseases. Oidium sp. Phomopsis sp. and other soil born fungi maintain damage on foliage and other parts of the tree. Fomes lignosus is causing the stem canker in the Philippines and can be fatal for rambutan trees if not controlled (MORTON, 1987a). 6.1.3 Economics in Sri Lanka There is not much information available about the economics of rambutan in Sri Lanka. However, rambutan is grown on medium scale commercial cultivation in Sri Lanka and the fruit has a high local demand (DOASL, 2007 and BARRY, 2007). The only data which could be found about the cultivation of rambutan are within the years 1995 to 1999 and show significant growth of the cultivation of rambutan with a production of 7168 metric tons and total land extent of 896 ha in the year 1999 (DOASL, 2007). Rambutan is a crop best suited to the mid-country and low-country wet zone of Sri Lanka. The main harvest season is July/August and sometimes, depending on the weather conditions, a small off-season harvest is gathered during December to February. The crop has good export potential and is presently exported in very limited amounts to the Gulf Region, France, Germany and UK. The most important variety is `Malwana Special´ followed by `Malaysian Red´ and ’Malaysian Yellow´ and some other local cultivars. Presently the most important areas where rambutan is grown successfully are within the districts of Gampaha and Colombo (DOASL, 2007). 6.2 Annona (Annona sp.) Annona belongs to the family Annonaceae which number of genera and species is still debated. Thereby varies the number of genera from 40 to 119 and the number of species from 500 to over 2000 (DE Q. PINTO et al., 2005, BAERTELS, 1990 and MAHDEEM, 1994). 13
Page 1: Control of Post Harvest Disease (Bo
Page 4 and 5: List of Figures Figure 1: The Sri L
Page 6 and 7: 1 Summary Experiments were undertak
Page 8 and 9: 3 Sri Lanka The Democratic Socialis
Page 10 and 11: 3.2 Climate The climate of Sri Lank
Page 12 and 13: valuable consultations in industria
Page 16 and 17: However, the most important genus i
Page 18 and 19: 6.2.1.2 Annona muricata Annona muri
Page 20 and 21: Figure 9: Annona squamosa Figure 10
Page 22 and 23: Characteristically for this fungus
Page 24 and 25: Figure 15: Phialides of Trichoderma
Page 26 and 27: autoclave is used for liquid steril
Page 28 and 29: Figure 21: Soil sampling in a rambu
Page 30 and 31: 9.1.4 Isolation of the pathogen Mat
Page 32 and 33: The effectivity of the BC-agent was
Page 34 and 35: Figure 29: Experimental series of a
Page 36 and 37: Two of the Trichoderma sp. with a h
Page 38 and 39: Results of the sporulation experime
Page 40 and 41: 12 References ALAM, M.S., BEGUM, M.
Page 42 and 43: ONG, P.K.C., ACREE, T.E. and LAVIN,
Page 44 and 45: Figure 36: List of bio-control agen
Page 46: Tmu III Galagedera • Mycelial gro

Botryodiplodia sp. - Crops for the Future

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