ARTIFICIAL FLOWERING IN TRIPLOCHITON SCLEROXYLON

• Published in: Journal of tropical forest science Vol. 23; no. 2; pp. 152 - 158
• Main Authors: Djagbletey, GD, Ofori, DA, Cobbinah, JR
• Format: Journal Article
• Language: English
• Published: Kuala Lumpur Forest Research Institute Malaysia 01.04.2011
• Subjects: Bark; Flower buds; Flowering; Fruit trees; Fruiting; Girdles; Graftage; Leaves; Trees; Tropical forests
• ISSN: 0128-1283; 2521-9847

Triplochiton scleroxylon is an important indigenous tropical hardwood species in West Africa. Due to its erratic flowering cycles, seeds are not readily available on a year to year basis, posing considerable difficulty in plantation establishment. To ensure abundance and continuous supply of planting stock, various treatments to induce flowering on grafts and mature trees were tested. These included spraying of urea solution on leaves, bark ringing and soil drenching with 2,4-dichlorophenoxyacetic acid solution. The studies were carried out in two agroecological zones in Ghana, namely, the dry and moist semi-deciduous ecozones. In the dry semi-deciduous ecozone, fruiting occurred from November—December 2005 in girdled (80%) and ungirdled (30%) trees whereas in the moist semi-deciduous ecozone there was less fruiting, i.e. girdled (40%) and ungirdled (0%) trees in the same period. In all plants (30), the region within 10 cm above and below the girdles were swollen four months after girdling. Soluble carbohydrate concentrations in the bark before flowering were higher above the girdle (8.5%) than below (6.0%). Leaf shedding and bud development were greatest in treatments with 50, 37.5 and 25% urea compared with 12.5 and 0% urea. The results suggest that T. scleroxylon can be artificially induced to flower. Triplochiton scleroxylon ialah spesies kayu keras tropika yang asli dan utama di Afrika Barat. Kitaran bunga T. scleroxylon yang tidak menentu mengakibatkan kuantiti biji benih berubah-ubah dari setahun ke setahun dan ini menyulitkan penubuhan ladang spesies tersebut. Untuk memastikan sumber stok penanaman yang banyak dan berterusan, beberapa rawatan untuk mengaruh pembungaan pada cantuman dan pokok matang diuji. Rawatan termasuk penyemburan daun dengan larutan urea, penggelangan kulit dan pelencunan tanah dengan larutan asid 2,4-diklorofenoksiasetik. Kajian dijalankan di dua zon ekologi tani di Ghana iaitu ekozon daun separa luruh kering dan ekozon daun separa luruh lembap. Di ekozon daun separa luruh kering, pembuahan berlaku dari bulan November—Disember 2005 pada pokok yang digelang (80%) dan pokok yang tidak digelang (30%). Pada tempoh yang sama, ekozon daun separa luruh lembap kurang berbuah iaitu pokok yang digelang (40%) dan pokok yang tidak digelang (0%). Empat bulan selepas penggelangan, kawasan 10 cm di atas dan di bawah gelang didapati bengkak pada semua pokok (30). Sebelum pembungaan, kepekatan karbohidrat terlarut dalam kulit adalah lebih tinggi di atas gelang (8.5%) berbanding bahagian bawah gelang (6.0%). Keguguran daun dan perkembangan tunas paling banyak dalam rawatan 50% = 37.5% = 25% urea berbanding rawatan 12.5% = 0%. Keputusan mencadangkan yang T. scleroxylon boleh diaruh untuk berbunga secara tiruan.