Physico-chemical properties of indigenous micro organism-composts and humic acid prepared from selected agro-industrial residues

Paddy husk (PH) and corn stalks (CS) residues are managed through burning. Besides contributing to environmental pollution, burning causes loss of vegetation cover, erosion, run off and loss of organic matter. In order to minimize this problem, a study was conducted to manage PH and CS residues through composting and to determine the physical and chemical properties of different composts and humic acid extracted from the final product. The study had six treatments namely: (T1) indigenous microorganisms (IMOIV)Steamed white rice (SWR)(30%)+PH (40%)+Chicken Dung (30%), (T2) SWR (30%)+CS (40%)+Chicken Dung (30%), (T3) IMOIVAerated Fish Pond Water (AFPW)(30%)+Paddy husk (40%)+Chicken Dung(30%), (T4) IMOIV AFPW (30%)+CS (40%)+Chicken Dung(30%), (T5) IMOIVKitchen Waste (KW)(30%)+PH (40%)+Chicken Dung (30%) and (T6) IMOIV KW (30%)+CS (40%)+Chicken Dung (30%). Composting was conducted in a white polystyrene box with a size of 30 x 15 x 25 cm. The composts produced in this study were analyzed for C:N and C:P ratio, pH (H2O and KCl), nutrients, heavy metals, organic carbon, organic matter, ash, cation exchange capacity (CEC), humic acid (HAs) and total microbial count. The HAs were evaluated for elemental composition, acidic functional groups, E4/E6 ratio and spectral characteristics using standard procedures. Results show that all IMO-composts were granular, dark brown in colour without foul odour and attained an ambient temperature at 34 days of composting indicating the stable nature of the composts. The number of bacteria and filamentous fungi involved during composting decreased at the end of the all treatments. The E4/E6, acidic functional groups; carboxyl-COOH, phenolic-OH and total acidity of the compost were consistent with the standard range. IMO-compost from CS had better quality (chemical characteristics) compared to that of paddy husk. High quality compost could be produced from CS.Keywords: Paddy husk (PH), corn stalks (CS), indigenous microorganisms (IMO)-compost, humid acid (HA

In vitro effects of salicylic acid, calcium and copper ions on growth and sporulation of Ganoderma boninense

The in vitro effects of single and combined application of calcium ion (Ca2+), copper ion (Cu2+) and salicylic acid (SA) were evaluated on growth and sporulation of Ganoderma boninense. In poison medium test, T7-(Ca+Cu+SA) showed effective control of G. boninense in-vitro with EC50 and EC90 values of 1500+150+150 ppm and 2000+200+200 ppm, respectively. However, in dipping test, T3-(SA) showed effective control for G. boninense in-vitro with EC50 and EC90 values of 50 ppm and 200 ppm, respectively. Interestingly, T7 (Ca+Cu+SA) indicate effective control of G. boninense at low concentration, 500+50+50 pmm as shown by EC90 analysis. Pre treatment of Ganoderma -infected rubber wood block with 500 ppm Ca + 50 ppm Cu + 50 ppm SA reduced the number (20.14%), size (1.20 cm2) and weight of basidiocarp (0.80 g) compared to the control. This was followed by a significant reduction in weight loss of the Ganoderma–infected rubber wood block (41.85%) suggesting the inhibition of the degradative enzymatic activity of the fungus. The mixture of Cu, Ca and SA had potential to suppress growth of G. boninense in vitro.Keywords: Ganoderma boninense, calcium chloride, copper- ethylenediaminetetraacetic acid (EDTA), salicylic acid, EC50 and EC9

Aggressiveness of Ganoderma boninense and G. zonatum isolated from upper- and basal stem rot of oil palm (Elaeis guineensis) in Malaysia

Currently, the most known devastating oil palm disease throughout South-east Asia is basal stem rot (BSR) caused by Ganoderma boninense. However, there is insufficient information on G. zonatum which also has been associated with the BSR, and upper stem rot (USR). Thus, this study reports pathological symptoms and degree of aggressiveness amongst G. zonatum and G. boninense of USR and BSR on oil palm seedlings. All the Ganoderma isolates tested showed positive signs of infection on the seedlings at 12 and up to 24 weeks after inoculation. However, the symptoms of infection on the seedlings were indistinguishable amongst the Ganoderma species tested. In fact, they showed significantly different degree of aggressiveness in terms of area under disease progress curve (AUDPC), epidemic rate, severity of foliar symp­toms (SFS), dis­ease severity index (DSI), stem bole necrosis and primary roots necrosis. The present findings suggested that G. zonatum of USR was the most aggressive, followed by G. zonatum and G. boninense of BSR, and G. boninense of USR was the least aggressive. Hence, a new mechanism of control strategies is urgently required to con­tain the disease from spreading especially for USR and also for G. zonatum in Malaysia

Disease prevalence and severity assessment of Pratylenchus coffeae on an infected banana in Peninsular Malaysia

Pratylenchus spp. cause considerable damage to the banana plant (Musa spp.) globally and although reported extensively in Malaysia, disease prevalence and infection severities have not been defined. The objective of this research, therefore, was to determine the prevalence of Pratylenchus coffeae and the extent of their damage on Musa spp. Of the 13 banana fields sampled, Pratylenchus nematodes were found in 76% of them. Proportions of root cortexes occupied by reddish brown lesion were significant in all the states. All the sampled areas exceeded the threshold limit, which is a 1% increment above 5% and is considered highly significant damage. The pathological reaction of P. coffeae against Pisang Berangan multiplications was observed after 12 weeks of growth in a glasshouse experiment. There were significant differences in vegetative growth within the various pathogen inoculation levels evaluated. Pisang Berangan showed a high level of susceptibility through the activity of polyphenol oxidase and peroxidase-induced resistance at all days after inoculation with P. coffeae compared to the control, except at week 12 where it declined or was non-significant from the control. Educating banana growers on the prevalence of this pathogenic parasite is therefore imperative for management decisions

Application of GIS for mapping the spatial distribution of ganoderma stem rot in oil palm plantations

Oil palm is widely cultivated in Indonesia and Malaysia. However, the sustainability of oil palm is threaten by Ganoderma species which cause stem rot disease. The outbreak of a disease or pathogen could be monitored using sophisticated tools, such as Geographical Information System (GIS). Thus, the objective of this study is to demonstrate the use of GIS in small scale to generate a spatial distribution map of Ganoderma species in an oil palm plantation. The study was conducted in a 16 hectare (200 x 800 m) experimental plot of oil palm plantation. Each palm within the plot were located based on the field planting row and column, and they were observed and coded either 0 for absence of Ganoderma or 1 for presence of Ganoderma. The data were collected from 2011 to 2012 at six months intervals. The data were then analyzed (interpolated) based on ordinary kriging fitted to spherical model of semivariogram using ArcMap of ArcGIS 10 to generate a spatial pattern map of Ganoderma species. The occurrence of Ganoderma in the study plot reached up to 9.80% during the study period. Graphical maps generated demonstrate spatial distribution pattern of Ganoderma, and they showed ranges of intensity (0 - 100%). Higher intensity indicates that there were higher occurrence of Ganoderma in a particular area, and vice versa. Moreover, there were changes in the spatial pattern throughout the year which indicate rapid spread of Ganoderma species. The information provided by the GIS map could be useful in various aspects. Keywords: Ganoderma; GIS; Oil palm; Spatial distribution

Aggressiveness of Ganoderma boninense and G. zonatum isolated from upper- and basal stem rot of oil palm (Elaeis guineensis) in Malaysia

Currently, the most known devastating oil palm disease throughout South-east Asia is basal stem rot (BSR) caused by Ganoderma boninense. However, there is insufficient information on G. zonatum which also has been associated with the BSR, and upper stem rot (USR). Thus, this study reports pathological symptoms and degree of aggressiveness amongst G. zonatum and G. boninense of USR and BSR on oil palm seedlings. All the Ganoderma isolates tested showed positive signs of infection on the seedlings at 12 and up to 24 weeks after inoculation. However, the symptoms of infection on the seedlings were indistinguishable amongst the Ganoderma species tested. In fact, they showed significantly different degree of aggressiveness in terms of area under disease progress curve (AUDPC), epidemic rate, severity of foliar symptoms (SFS), disease severity index (DSI), stem bole necrosis and primary roots necrosis. The present findings suggested that G. zonatum of USR was the most aggressive, followed by G. zonatum and G. boninense of BSR, and G. boninense of USR was the least aggressive. Hence, a new mechanism of control strategies is urgently required to contain the disease from spreading especially for USR and also for G. zonatum in Malaysia

Consolidated evaluation of polysaccharide degradation after oil palm wood pretreatment with indigenous white-rot hymenomycetes

The oil palm industry is the backbone of the Malaysian economy. However, this industry is threatened by basal stem rot (BSR) caused by the fungus Ganoderma boninense, which has caused severe losses over the past several decades. The study reported here is part of an ongoing project to reduce Ganoderma inoculum and manage oil palm waste on plantations, which could be a green technology approach to reduce BSR infection pressure. A preliminary search for potential white-rot hymenomycetes to accelerate the degradation of oil palm stumps has been initiated. As a continuity, the present study was designed to comprehensively investigate the changes in wood crystallinity at different stages of oil palm wood degradation after pretreatment with three white-rot hymenomycete species. The findings were used to limit potential white-rot candidate(s) for their secretion of cellulolytic, hemicellulolytic and amylolytic enzymes, selectively or simultaneously, using principal component analysis. The overall per cent crystallinity of healthy wood decayed by Lentinus tigrinus increased as degradation proceeded. Conversely, crystallinity generally increased at 75 d in the diseased wood pretreated with Trametes lactinea, owing to the preferential degradation of noncrystalline lignins and hemicelluloses by this strain. Anatomical characterization revealed penetration of fungal mycelia into the degraded wood vessels, phloem and parenchymal tissues with microscopic cavities. In advanced stages of pretreatment, the loosening of the parenchymal tissue, including the wood rays, was more rapid in the diseased wood than in the healthy wood. This study provides new insights into the biochemical and anatomical changes initiated by white-rot hymenomycetes during the degradation of oil palm wood blocks. The present findings could be efficiently utilized for sustainable biological stump pretreatment, particularly with respect to the polysaccharide components of lignocellulosic materials

Ganoderma species of basal and upper stem rots in oil palm (elaeis guineensis) in Sarawak, Malaysia

Oil palm is one of the most important plantation crops in Malaysia. The sustainability of oil palm is threatened by Ganoderma species. It is commonly known that Ganoderma boninense is the causal pathogen for basal stem rot (BSR) in oil palm. However, little is known about the threats by other species of Ganoderma or upper stem rot (USR), which is associated with a similar pathogen. A total of 46 isolates of Ganoderma were isolated from BSR and USR infected oil palms. The isolates were identified using a multiplex PCR, and its genetic heterogeneity was determined using a somatic compatibility test. It was found that BSR and USR coexisted in the plantations, and USR emerged as one of the major diseases. The diseases were associated with similar pathogens, namely G. zonatum (71.7%), followed by G. boninense (26.1%), and G. miniatocinctum (2.2%). Somatic compatibility test indicated that all the isolates were genetically heterogeneous. These results show that G. zonatum and the transmission of the diseases through basidiospores play a vital role in the epidemiology of the diseases. Thus, USR should not be overlooked, and more emphasis should be given to G. zonatum and its mode of transmission for more effective disease management

Trends in nanotechnology and its potentialities to control plant pathogenic fungi: a review

Approximately 15–18% of crops losses occur as a result of animal pests, while weeds and microbial diseases cause 34 and 16% losses, respectively. Fungal pathogens cause about 70–80% losses in yield. The present strategies for plant disease control depend transcendently on agrochemicals that cause negative effects on the environment and humans. Nanotechnology can help by reducing the negative impact of the fungicides, such as enhancing the solubility of low water-soluble fungicides, increasing the shelf-life, and reducing toxicity, in a sustainable and eco-friendly manner. Despite many advantages of the utilization of nanoparticles, very few nanoparticle-based products have so far been produced in commercial quantities for agricultural purposes. The shortage of commercial uses may be associated with many factors, for example, a lack of pest crop host systems usage and the insufficient number of field trials. In some areas, nanotechnology has been advanced, and the best way to be in touch with the advances in nanotechnology in agriculture is to understand the major aspect of the research and to address the scientific gaps in order to facilitate the development which can provide a rationale of different nanoproducts in commercial quantity. In this review, we, therefore, described the properties and synthesis of nanoparticles, their utilization for plant pathogenic fungal disease control (either in the form of (a) nanoparticles alone, that act as a protectant or (b) in the form of a nanocarrier for different fungicides), nano-formulations of agro-nanofungicides, Zataria multiflora, and ginger essential oils to control plant pathogenic fungi, as well as the biosafety and limitations of the nanoparticles applications