Pathogenicity study of ceratocystis acaiivora and ceratocystis manginecans associated with wilting & dieback diseases on acacia mangium at Acacia Forest Industry {AFI), Sabah

• Main Author: Khesnii Shiv Ram
• Format: Thesis
• Language: English
• Published: 2019
• Subjects: SD Forestry
• Online Access: https://eprints.ums.edu.my/id/eprint/25102/1/Pathogenicity%20study%20of%20ceratocystis%20acaiivora.pdf; https://eprints.ums.edu.my/id/eprint/25102/

A radical rise posting in the incidence of wilting and dieback diseases induced by plant pathogenic fungi Ceratocystis sp. in commercially planted Acacia mangium are major problem faced by industrial plantations such as Acacia Forest Indusby (AFI) Plantation. Two types of Ceratocystis isolates; Ceratocystis manginecans (AFI/CM/001) and Ceratocystis acaciivora (AFI/CN00l) are recognized and collected from AFI Plantation in Pitas, Sabah. The general aim is to scientifically determine the immensity of Ceratocystis isolates to induce disease on plantation grown A. mangium using pathogenicity and interaction study. On this objective, field inoculation is done in the plantation nursery and interaction behavior is to be observed in-vitro. In field inoculation, 100 A. mangium seedlings were inoculated with C manginecans and C acaciivora to observe the ability of both fungi to induce diseases for 6 weeks. The efficacy study shows both fungi have capability to enhance lesion on A. mangium seedlings. C manginecans isolate produced longer lesions (mean=47.103) compared to C acaciivora isolate (mean=42.940), the difference is not significant (p=0.148, F=2.099). Yet, C. acaciivora showed a more linear growth in lesion increment compared to C. manginecans by weekly observation. Dual culture method was used to assess the ability of 6 test isolates which were identified during the isolation of infected A. mangium sample to control C. manginecans and C acaciivora, which causes the wilting and dieback diseases. The highest percentage inhibition of radical growth (PIRG) values was observed with isolate KHES/AFI-UMS/D00l; Trichoderma sp (60.00%; C. manginecans and 53.33%; C. acaciivora) and the lowest recorded (15.55%; C. manginecans and 21.67%; C. acaciivora) were observed with isolate KHES/AFI-UMS/E00l; Verticillium sp. This study showed that isolate Trichoderma sp. has a good antagonistic effect on C.manginecans and C acaciivora mycelial growth. Diseases developments from Cmanginecans and C. acaciivora inoculated samples which suggesting that this fungus is the primary cause of the wilting of trees under natural conditions.