INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY ISSN Print: 1560–8530; ISSN Online: 1814–9596 16–564/2017/19–2–299–306 DOI: 10.17957/IJAB/15.0280 http://www.fspublishers.org Full Length Article To cite this paper: Nusaibah, S.A., G. Saad and T.G. Hun, 2017. Antagonistic efficacy of Trichoderma harzianum and Bacillus cereus against Ganoderma disease of oil palm via dip, place and drench artificial inoculation method. Int. J. Agric. Biol., 19: 299‒306 Antagonistic Efficacy of Trichoderma harzianum and Bacillus cereus against Ganoderma Disease of Oil Palm via Dip, Place and Drench (DPD) Artificial Inoculation Technique S.A. Nusaibah 1* , Ghazala Saad 2 and Tan Geok Hun 3 1 Department of Plant Protection, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 2 Department of Plant Production, Faculty of Agriculture, Azzaytona University, Baniwaleed Campus Tripoli, Libya 3 Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia * For correspondence: nusaibah@upm.edu.my Abstract Sustainability of the oil palm industry is crucial to ensure Malaysia's gross domestic product (GDP) by the agricultural sector. It is crucial to discover a sustainable and eco-friendly remedy for the most devastating Ganoderma disease of oil palm. The effects of pre-inoculation of oil palm seedlings with either Trichoderma harzianum and/or Bacillus cereus on their vegetative growth and the suppression of Ganoderma boninense were investigated. The dip, place and drench (DPD) artificial inoculation method was used to assure disease development. Disease severity was assessed based on the root symptoms (DS), disease incidence (DI) and disease reduction (DR). Application of a mixture of T. harzianum and B. cereus had the highest contribution to the vegetative growth of oil palm seedlings. However, single application of B. cereus was found to be the most effective treatment in suppressing Ganoderma disease of oil palm with a disease reduction of 94.75% followed by single applications of T. harzianum (78.98%) and mixture of both T. harzianum and B. cereus (68.49%). © 2017 Friends Science Publishers Keywords: Dip, place and drench (DPD); Bacillus cereus; Trichoderma harzianum; Biocontrol Introduction Oil palm (Elaeis guineensis Jacq.) is a tropical perennial crop, purposely for oil. The oil extracted from this crop is used world-wide for different industrial applications including cosmetics, oleo-chemicals, food and biofuel (Murphy, 2009; Paterson et al., 2009). This golden crop has been contributing generously to Malaysia’s economy. However a major disease caused by Ganoderma boninense has been a treat to Malaysia’s oil palm industry for many years and the estimated lost per annum was recorded as earnings of US$20 billion in terms of export earnings (MPOB, 2011) Therefore, there is an obvious need for understanding and developing an early control that will contribute to a sustainable environment along with catering this catastrophic disease (Paterson et al., 2009; Flood et al., 2010). Government legislature for reducing the consumption of chemical fungicides had triggered an increasing public awareness on the hazards and the importance in attempting the search for alternatives of synthetic chemical fungicides. Hence, efforts to find an alternative way to control Ganoderma disease via biological control agents (BCAs) and utilization of resistant oil palms (Susanto et al., 2005) have been a better approach. In vitro studies have shown that Trichoderma spp., Aspergillus spp., and Penicillum spp. are antagonistic agents towards Ganoderma spp. (Bruce and Highley, 1991; Badalyan et al., 2004). These antagonists, particularly Trichoderma spp., are good BCAs of Ganoderma spp. (Bruce and Highley, 1991; Susanto et al., 2005). A part from fungus, endophytic bacteria was reported with the ability to enhance plant’s immune system against pathogen attack. This is done by winning competition, antibiosis, induced resistance and promoting plant growth. Endophytic bacteria such as Pseudomonas and Bacillus spp. were found to be potent BCAs against fungal pathogens on crops such as cotton, oilseed rape, tomato, cucumber and peas (Chen et al., 1995; Alstrom, 2001). In addition, some members of the genus Bacillus such as B. cereus are often considered as microbial factories of biologically active molecules that are potential inhibitors of fungal growth (Pérez-García et al., 2011). Besides that, recent control measures to overcome Ganoderma infection in palms are now focused on the use of BCAs. Subsequently, research on the use of BCAs for Ganoderma disease control has gained momentum.