Arnnyitte Alexander

Morphological changes of Ganoderma boninense mycelia after challenged by Trichoderma and Bacillus

Ganoderma boninense is a fungal pathogen that causes Basal Stem Rot (BSR) disease in oil palm. This deadly disease has caused major losses in the oil palm industry and no remedy is reported to date. The more promising control on G. boninense is the use of biological control agents (BCAs). Despite many attempts in using BCAs as a control agent but evidence on the colonization of BCAs and morphological changes of the pathogen is not well documented. We have investigated the effect of antagonist activity on the combination of Trichoderma spp. and Bacillus spp. on the morphology of G. boninense. The antagonist activity was evaluated using agar well diffusion assay. BCAs suppressed the mycelia growth of G. boninense up to 70%. Observation under Scanning Electron Microscopy (SEM) shows these BCAs induced stripping of G. boninense hyphal structure by destroying the cellular structure. Highly disrupted, disaggerated, shrivelled and lysis of G. boninense hyphal were also observed. The antifungal activity of Tricho...

Pathogenic Nature of Ganoderma boninense and Basal Stem Rot Disease

The oil palm industry is under threat of a prevailing incurable disease called Basal Root Stem (BSR), which is caused by a white rot fungi, known as Ganoderma boninense . With no current remedy at present, BSR is the major disease in oil palm plantations of SEA and, therefore, of great economic importance to the world oil palm industry, especially to Malaysia and Indonesia, which are oil palm major producers and exporters. The disease is highly associated with the decay of lower stem, leading to severe symptoms such as unopened and flattening spear leaves. There are numerous mode of infection associated with the epidemiology of G. boninense in oil palm plantation, including in-contact roots with nearby diseased palms and through airborne basidiospores . Deep insight on the route of infection and mycological pathogenicity behaviour of the pathogen is the greatest priority in order to successfully develop effective management practices for disease control.

Control Methods of G. boninense in Oil Palm Industry

Basal Stem Rot (BSR) is a very important disease to the oil palm industry. When it was first recorded, BSR only affected mature palms. However after years, the disease had progressed to affecting younger palms and causing more losses. The disease continues to inflict considerable yield losses of infected palms and also direct loss of stand due to palm death. Attempts to control the disease has been taken to wider extent, including cultural practices (clean clearing , windrowing , mounding, surgery, digging trenches, sanitation ), fungicide application, development of resistance variety and application of biological control agents . This chapter elaborates all possible managing strategies in combating Ganoderma boninense.

Current Detection Methods of G. boninense Infection in Oil Palm

Basal Stem Rot (BSR) disease has been spreading fast due to the inability to detect infection at the early stage in the field. The detection of the disease is challenging because the external symptoms are only visible when it is at the critical stage. During this stage, any treatment or management methods are no longer effective. Therefore, many viable and effective methods to detect the presence of G. boninense has been developed to diagnose the disease at early stage. This chapter elaborates established methods in detecting G. boninense including molecular analysis, biochemical assay, field detection methods using devices and some others emerging methods currently utilized.

Control of G. boninense Using Multi-biological Agents

Available control measures in managing Basal Stem Rot (BSR) disease has given unsatisfactory result. Alternative control measure to overcome this disease are now focused on the use of Biological Control Agents (BCAs) . Currently introduction of Multiple Biological Agents (Multi-BCAs) to expand their mode of action has been applied in managing plant pathogen. Selecting the right combination of antagonists is necessary not only to avoid competition among the BCAs but also complementing each other. In addition, a different ecological requirement of BCAs would broaden the range of environmental conditions and made the biological control more feasible. Most combinations are only involving two organisms, but few involved combinations of three or more organisms. In this chapter, the efficacy of microbes using combinations of microbes which are solely Multi-BCAs and Multi-BCAs with additive against Ganoderma boninense are discussed.