Potential of Bacillus subtilis inoculation in Biorichar™ amended soil for suppression of Fusarium wilt of banana (Musa acuminata cv. Berangan) under water stress condition

The present research was conducted to evaluate the ability of Bacillus subtilis to supress Fusarium wilt disease of banana in Biorichar™ amended soil under different soil moisture regimes. Banana plants were inoculated with different volumes of Bacillus subtilis (0, 20, 40 and 60 mL) given at concentration 108 CFU mLˉ¹ and subjected to three water stress levels based on field capacity (FC) viz. well watered (100% FC), mild stress (75% FC), and severe stress (50% FC). Banana plantlets were inoculated with Fusarium oxysporum one week after Bacillus subtilis were applied. The results showed that, minimum percentage of disease incidence in banana plants was recorded at high Bacillus subtilis rate (40 mL and 60 mL) at 50% FC. However, at 75% FC and 100% FC conditions, disease incidence increased from 35.28% to 45.09% following the time. Proline content showed 0.33% high under 75% FC compared to 50% FC at 45 DAT and similar trend was observed at 90 DAT. Malondialdehyde (MDA) content in banana plants was high in control treatment than those inoculated with Bacillus subtilis. 100% FC condition gave significantly higher net photosynthesis (14.95%), stomatal conductance (60.47%), transpirations rate (54.58%) and vapor pressure deficit (14.14%) compared to 50% FC at 45 DAT. However, values of net photosynthesis at 90 DAT were 30.07% and 20.79% lower at 50% FC and 100% FC, respectively in comparison to the values recorded at 45 DAT as pathological process progressed. Inoculation of Bacillus subtilis @ 60 mL increased photosynthesis rate by 9.07% as compared to non-inoculated plantlets at 100% FC at 45 DAT. However, no significant difference observed when the plants were inoculated by Bacillus subtilis @ 40 mL and @ 60 mL under 75% FC condition. Therefore, inoculation of Bacillus subtilis @ 60 mL could be a promising biological control agent that can trigger resistance against Fusarium wilt in susceptible Berangan banana under water stress condition

Influence of Water Stress in Association with Aplication of Brassinolide and Minerals on Growth, Physiological and Biochemical Changes of Banana (Musa acuminata cv. Berangan)

Water stress or synonymy referring to the drought season is the major abiotic stress which affect growth, physiology and biochemical activity in plant and cause major losses to agriculture production sector. This study was aimed to determine the effects of exogenous application of brassinolide (BR) and combination of minerals on growth performance, physiological and biochemical changes of banana plantlets (Musa acuminata cv. Berangan) under water stress condition. The leaves of the whole plantlets were foliar sprayed for every two weeks interval with three treatments; (i) BR as control, (ii) magnesium carbonate (MgCO3) + calcium carbonate (CaCO3) and (iii) combination of BR + MgCO3 + CaCO3. The plants were also subjected to water stress treatments: 50%, 75% and 100% of the field capacity. The treatments were assigned as split-plot design in randomized complete block design (RCBD) arrangement. Water stress had significantly reduced major growth parameters (plant height, pseudo-stem diameter and total leaf area) but enhanced accumulation of proline and malondialdehyde content in leaves tissue. These findings also provided profound new insights and water stress by regulating the changes on stomata conductance and vapour pressure deficit under severe water stress condition

Influence of Water Stress in Association with Aplication of Brassinolide and Minerals on Growth, Physiological and Biochemical Changes of Banana (Musa acuminata cv. Berangan)

Water stress or synonymy referring to the drought season is the major abiotic stress which affect growth, physiology and biochemical activity in plant and cause major losses to agriculture production sector. This study was aimed to determine the effects of exogenous application of brassinolide (BR) and combination of minerals on growth performance, physiological and biochemical changes of banana plantlets (Musa acuminata cv. Berangan) under water stress condition. The leaves of the whole plantlets were foliar sprayed for every two weeks interval with three treatments; (i) BR as control, (ii) magnesium carbonate (MgCO3) + calcium carbonate (CaCO3) and (iii) combination of BR + MgCO3 + CaCO3. The plants were also subjected to water stress treatments: 50%, 75% and 100% of the field capacity. The treatments were assigned as split-plot design in randomized complete block design (RCBD) arrangement. Water stress had significantly reduced major growth parameters (plant height, pseudo-stem diameter and total leaf area) but enhanced accumulation of proline and malondialdehyde content in leaves tissue. These findings also provided profound new insights and water stress by regulating the changes on stomata conductance and vapour pressure deficit under severe water stress condition

Effect of BioRichar amendment on growth, nutritional properties and biochemical changes of banana (Musa acuminata) cv. Berangan established in an ultisol soil at vegetative stage

Enrichment of soil fertility with organic amendment offers a new strategy for enhancing soil physical properties and improving soil fertility. Application of BioRichar can be a new alternative for adoption of organic banana cultivation in Malaysia. This study was conducted to determine optimum BioRichar rate for growth enhancement of banana cv. Berangan at vegetative stage. The BioRichar was mixed thoroughly with ultisol soil at 1.5, 3.0 and 4.5 t/ha, which were equivalent to 0.6, 1.2 and 1.8 kg/ polybag (size 16 x 16 inches), respectively. In the experiment, BioRichar at 3.0 t/ha and 4.5 t/ha improved plant growth characteristics significantly including plant height, pseudo-stem diameter, total leaf number and leaf area as compared to control. Application of 4.5 t/ha BioRichar changed total N, P, K, Ca and Mg significantly in leaves. Total N, P, K increased but Ca and Mg content decreased significantly, when BioRichar was applied at higher rate (4.5 t/ha). Meanwhile, proline and MDA contents in leaf tissue were higher in control as compared to BioRichar enriched plants. These findings suggested that optimum growth of banana cv. Berangan could be achieved with BioRichar at 4.5 t/ha applied at vegetative stages during acclimatization period prior to field transplanting

Effect of different water regimes and plant growth regulators on growth, physiology and yield of banana (Musa acuminata cv. Berangan) in tropical climate

A field investigation under tropical climate was undertaken in the research plot of the Universiti Putra Malaysia, Selangor, Malaysia to study the effects of exogenous application of plant growth regulators on growth performance, physiology changes and biochemical analysis of banana plants (Musa acuminata cv. Berangan) under irrigated and rainfed condition. The experiment was laid out as split-plot in randomized complete block design. Results showed that, banana plants grown under the rainfed condition significantly reduced morphological characters such as plant height, pseudo-stem, canopy diameter, but enhanced accumulation of proline and malondialdehyde content in leaves tissue of stress-treated plants. Physiological characters which include total chlorophyll content, relative water content and electrolyte leakage were measured and has indicated significant effect under two different water regimes. Application of plant growth regulators on Berangan banana under different water regimes able to tolerate water stress conditions by changes in vapour pressure deficit as affected by decreasing stomata opening besides enhanced net photosynthesis to produce higher yield of banana fruits

Identification and characterization of fungal species causing anthracnose disease on mango (Mangifera indica L.

Mango (Mangifera indica L.) belongs to the family Anacardiaceae is grown primarily in Malaysia valued for local mango production and has high nutritional value. One of the major problem pre and post-harvest diseases on mango is anthracnose disease caused by many fungal species in the genus Colletotrichum. Symptoms of the disease included irregular, circular dark brown spot appear on the young leaves, flowers and fruits. In Malaysia, there is limited research on the composition of fungal species responsible for mango anthracnose. The objectives of this study are; 1) to isolate pure culture of fungal isolates causing anthracnose on mango fruits and leaves; 2) to identify fungal pathogens to species level based on morphological characteristics and polymerase chain reaction (PCR) protocol using ITS4 and ITS5 primers; and 3) to construct internal transcribed spacer (ITS) phylogeny of the fungal species using maximum likelihood analysis. To accomplish these objectives, symptomatic fruits were collected from five different mango trees at Taman Pertanian Universiti (TPU), Universiti Putra Malaysia. Infected tissues (5 x 5mm) from the lesions margin was being surface disinfected for 2 min with 10% Clorox and cultured on potato dextrose agar (PDA). The pure fungal isolates isolated from fruit lesions were identified by conidial and in vitro morphological characteristics according to Mordue et al.,(1971). The fungal isolates were sub-cultured by single spore isolation and the representative was characterized further. DNA genomic was extracted from fresh fungal mycelium by using protocol of DNeasy Plant Mini Kit from QIAGEN. The internal transcribed spacer (ITS) region of the ribosomal DNA was amplified using primers ITS4 and ITS5. The PCR product of the ITS was sequenced and analyzed using BLAST nucleotide query in GenBank. In this study, all fungal isolates match to the sequence of Colletotrichum asianum within C.gloeosporiodes species complex. This study is a significant step forward management recommendation in controlling anthracnose in mango production areas

Effects of enriched biochar and Bacillus subtilis on growth, physio-biochemical properties and fusarium wilt incidence of banana under water stress

Banana (Musa acuminata cv. Berangan) is one of the most popular fruit and has great potential for commercial development since the current demand had increased drastically. However, in Malaysia, poor soil fertility, limited water availability and disease attack are among common problems in banana industry. In order to find a solution of the problems, a field study was conducted to determine the optimum enriched biochar rate for improvement of soil physicochemical properties, growth and physiological status of banana. In addition to field study, a glasshouse study was conducted to determine the effect of Bacillus subtilis inoculation in enriched biochar media and water stress on growth, physiological status and suppression of Fusarium wilt. Four different rates of enriched biochar (0, 1.5, 3.0 and 4.5 t ha⁻¹ ) were applied once by mixing with Bungor Series soil and put into a polybag with the size of 40 cm × 40 cm. One month old banana plantlets were used. The treatments were carried out for 3 months and arranged in a randomized complete block design with 4 replications. Meanwhile, in the second study, the media were prepared based on optimum rate of enriched biochar from the first study. The treatments consisted of two factors (water stress and Bacillus subtilis) arranged by split plot in randomized complete block design with three replications. The media were enriched with 0, 20, 40 and 60 mL Bacillus subtilis at the concentration 10⁸ CFU mL⁻¹ applied by soil drenching as pre-inoculation treatments and plantlets were subjected to 100% well- watered (WW), 75% medium-stressed (MS) and 50% severe-stressed (SS) treatments based on field capacity (FC) level. The plantlets inoculated with Fusarium oxysporum race 4 (FOC) one week after Bacillus subtilis treatments were applied and the plant were destructively sampled at 45 and 90 days after transplanting (DAT). The results found that soil microbial population, soil physicochemical properties (pH, CEC, total C, N, K, Ca and Mg), growth characteristics (plant height, pseudo- stem diameter, total leaf number and total leaf area), mineral content in leaf tissue (N, P, K, Ca and Mg) and photosynthesis rate increased with the increasing rate of enriched biochar and 4.5 t ha⁻¹ was selected as the best treatment. SS treatment significantly reduced growth parameters and physiological status (photosynthesis, stomatal conductance, transpiration and relative water content) and increased accumulation of proline and malondialdehyde content in plant tissue. Chlorophyll content showed increased by higher rates of Bacillus subtilis at both 45 and 90 DAT of destructive period. High concentrations of Bacillus subtilis (40 and 60 mL) also were found to reduce disease severity under SS but the value increased under MS and WW condition following the time. This finding suggested that, soil amendment with enriched biochar at 4.5 t ha⁻¹ was adequate for optimum growth at nursery level (vegetative stages up to 3 months). Inoculation of the media with higher rates of Bacillus subtilis able to improved growth, physiological status and nutritional properties of the banana plants under water stress condition, reduced the deleterious effects of stress and helped plantlets to tolerate drought stress to a higher level as compared to non-inoculated plantlets and increase resistance to Fusarium wilt