Control Of Crown Rot Research Articles

The G143S mutation in cytochrome b confers high resistance to pyraclostrobin in Fusarium pseudograminearum.

Wheat crown rot (WCR), primarily caused by Fusarium pseudograminearum has become more and more prevalent in winter wheat areas in China. However, limited fungicides have been registered for the control of WCR in China so far. Pyraclostrobin is a representative quinone outside inhibitor (QoI) with excellent activity against Fusarium spp. There is currently limited research on the resistance risk and resistance mechanism of F. pseudograminearum to pyraclostrobin. Here, we determined the activity of pyraclostrobin against F. pseudograminearum. The EC50 values ranged from 0.022 to 0.172 μg mL-1 with an average EC50 value of 0.071 ± 0.030 μg mL-1. Four highly pyraclostrobin-resistant mutants were obtained from two sensitive strains by ultraviolet (UV) mutagenesis in the laboratory. The mutants showed decreased mycelial growth rate and virulence as compared with the corresponding wild-type strains, indicating that pyraclostrobin resistance suffered a fitness penalty in F. pseudograminearum. It was found that the high resistance of four mutants was caused by the G143S mutation in Cytb. Molecular docking analysis also further confirms that the G143S mutation in Cytb decreased the binding affinity between pyraclostrobin and Cytb. The resistance risk of F. pseudograminearum to pyraclostrobin could be low to medium. Although a mutation at the G143S position of Cytb could potentially occur, this mutation decreases the fitness of the mutant, which may reduce its survival in the environment. Therefore, the negative consequences of a possible mutation are lower. This makes pyraclostrobin a good candidate for controlling crown rot in wheat. © 2024 Society of Chemical Industry.

The critical roles of the Zn2Cys6 transcription factor Fp487 in the development and virulence of Fusarium pseudograminearum: A potential target for Fusarium crown rot control

Fusarium crown rot (FCR) caused by Fusarium pseudograminearum poses a significant threat to wheat production in the Huang-Huai-Hai region of China. However, the pathogenic mechanism of F. pseudograminearum is still poorly understood. Zn2Cys6 transcription factors, which are exclusive to fungi, play pivotal roles in regulating fungal development, drug resistance, pathogenicity, and secondary metabolism. In this study, we present the functional characterization of a Zn2Cys6 transcription factor F. pseudograminearum, designated Fp487. In F. pseudograminearum, Fp487 is shown to be required for mycelial growth through gene knockout and phenotypic analyses. Compared with wild-type CF14047, the ∆Fp487 mutant displayed a slight reduction in growth rate but a significant decrease in conidiogenesis, pathogenicity and 3-acetyl-deoxynivalenol (3AcDON) production. Moreover, the mutant exhibited heightened sensitivity to oxidative and cytomembrane stress. Furthermore, we synthesized dsRNA from the Fp487 gene in vitro, resulting in a reduction in the growth rate of F. pseudograminearum and its virulence on barley leaves through spray-induced gene silencing (SIGS). Notably, this study makes the first instance of inducing the expression of abundant dsRNA from F. pseudograminearum by engineering the Escherichia coli strain HT115 (DE3) and utilizing the SIGS technique to evaluate the virulence effect of dsRNA on F. pseudograminearum. In conclusion, our findings revealed the crucial role of Fp487 in regulating pathogenicity, stress responses, DON production, and conidiogenesis in F. pseudograminearum. Furthermore, Fp487 is a potential RNAi-based target for FCR control.

Effect of fludioxonil on morphological characteristics of Fusarium pseudograminearum and wheat crown rot control

Effect of fludioxonil on morphological characteristics of Fusarium pseudograminearum and wheat crown rot control

Control of crown rot with potassium carbonate in banana cv. Enano Gigante

AbstractThe postharvest antifungal activity of potassium carbonate (PC) against crown rot (CR) was investigated in banana cv. Enano Gigante by artificially inoculating with Colletotrichum musae (Cm) and incubating at 25 ± 1°C for 7 days. PC treatments were tested by in vitro and in vivo primary experiments. The in vivo preliminary concentration of 175 mM PC was selected as the most effective and was used in subsequent experiments on the influence of dip temperature on the effectiveness of PC. Curative dip treatments of 175 mM PC at 40°C for 20 min applied alone or combined with low doses of thiabendazole (TBZ) were evaluated on CR. Finally, the effect of PC on banana fruit quality was determined. PC at 150 and 200 mM totally inhibited mycelial growth and conidial germination of Cm. In in vivo primary experiments, 175 mM PC significantly reduced both the incidence (33.3% reduction) and the severity (90.5% reduction) of CR, but only in curative treatments. When the 175 mM PC dip for 20 min was tested at different temperatures, the curative dip at 40°C was the most effective, reducing CR incidence and severity by 91.6% and 98.8%, respectively, and was used for subsequent experiments. PC combined with TBZ at 225 μL L−1 did not improve the curative control effectiveness on CR compared to PC alone. PC did not affect the quality of banana fruit.

Coconut Mesocarp Extracts to Control Fusarium musae, the Causal Agent of Banana Fruit and Crown Rot

Crown rot, caused by Fusarium species, is the most devastating postharvest disease in bananas. Fungicides are traditionally applied as a postharvest treatment to control crown rot in bananas. However, there is a need to research environmentally friendly compounds as postharvest treatments instead of chemical fungicides. The phenolic compounds gallic acid, protocatechuic acid, and chlorogenic acid were identified in coconut mesocarp extract. Overall, the treatments were more efficient in crown-based than fruit-based culture mediums. The mycelial development was inhibited in a range from 20 to 26% (applying coconut mesocarp extract at 5%) compared to the control. Sporulation and spore germination were significantly inhibited, with a reduction of 88% in spore production and 91% in spore germination inhibition compared to the control. In in vivo tests, the aqueous extracts were effective by limiting the percentage of infected fruit, crown rot, and fruit severity. The use of coconut mesocarp extracts can be an effective and environmentally friendly alternative to the use of fungicides for controlling Fusarium musae on bananas.

Impact of Phenamacril on the Growth and Development of Fusarium pseudograminearum and Control of Crown Rot of Wheat.

Fusarium pseudograminearum is the dominant pathogen causing Fusarium crown rot (FCR) of wheat. Phenamacril is a 2-cyanoacrylate fungicide, having a control effect on diseases caused by Fusarium spp. The objective of this study was to investigate the inhibitory effect of phenamacril on F. pseudograminearum and its control efficacy against FCR. The results showed that phenamacril had a strong inhibitory effect on the mycelial growth of F. pseudograminearum, EC50 values of phenamacril to 63 tested strains were in the range of 0.0998 to 0.5672 μg/ml, and the average EC50 value was 0.3403 ± 0.0872 μg/ml and could be used as the baseline sensitivity of F. pseudograminearum to phenamacril. Phenamacril reduced the germination rate of conidia of F. pseudograminearum, and the EC50 value was 5.0273 to 26.4814 μg/ml. In addition, we found that phenamacril had a teratogenic effect on conidia and blastotubules, which increased the ratio of conidial germination from the middle cells and showed high efficacy on the sporulation quantity of F. pseudograminearum with an EC50 value in the range of 0.0770 to 0.1064 μg/ml. There was no significant correlation between the sensitivity of F. pseudograminearum to phenamacril and its sensitivity to fludioxonil, carbendazim, tebuconazole, and kresoxim-methyl. In vitro and greenhouse assays showed that the treatment with 0.125 μl of active ingredient per gram recorded the best control effect on wheat crown rot, reaching 87.8 and 77.3%, respectively. In two experimental sites in Luoyang, phenamacril also had great control effect against FCR, reaching 83.9%. It was proven that phenamacril has a superior control effect against FCR. This study has laid a foundation for the study of the mechanism of action of phenamacril against F. pseudograminearum and provided a theoretical basis for the application of phenamacril to control FCR.

On the use of hot water treatment to control crown rot postharvest diseases of export banana fruit (Musa sp., Group AAA, subgroup Cavendish, ‘Williams’)

On the use of hot water treatment to control crown rot postharvest diseases of export banana fruit (<i>Musa</i> sp., Group AAA, subgroup Cavendish, ‘Williams’)

Proteomic and physiological analysis provides an elucidation of Fusarium proliferatum infection causing crown rot on banana fruit

Fusarium proliferatum causes the crown rot of harvested banana fruit but the underling infection mechanism remains unclear. Here, proteomic changes of the banana peel with and without inoculation of F. proliferatum were evaluated. In addition, we investigated the effects of F. proliferatum infection on cell structure, hormone content, primary metabolites and defense-related enzyme activities in the banana peel. Our results showed that F. proliferatum infection mainly affects cell wall components and inhibits the activities of polyphenoloxidase, peroxidase, and chitinase. Gel free quantitative proteomic analysis showed 92 down-regulated and 29 up-regulated proteins of banana peel after F. proliferatum infection. These proteins were mainly related to defense response to biotic stress, chloroplast structure and function, JA signaling pathway, and primary metabolism. Although jasmonic acid (JA) content and JA signaling component coronatine-insensitive (COI) protein were induced by F. proliferatum infection, JA-responsible defense genes/proteins were downregulated. In contrast, expression of senescence-related genes was induced by F. proliferatum, indicating that F. proliferatum modulated the JA signaling to accelerate the senescence of banana fruit. Additionally, salicylic acid (SA) content and SA signaling for resistance acquisition were inhibited by F. proliferatum. Taken together, these results suggest that F. proliferatum depolymerizes the cell wall barrier, impairs the defense system in banana fruit, and activates non-defensive JA-signaling pathway accelerated the senescence of banana fruit. This study provided the elucidation of the prominent pathways disturbed by F. proliferatum in banana fruit, which will facilitate the development of a new strategy to control crown rot of banana fruit and improvement of banana cultivars.

Developing Actinobacterial Endophytes as Biocontrol Products for Fusarium pseudograminearum in Wheat.

Crown rot of wheat, caused by Fusarium pseudograminearum, results in millions of dollars of yield losses globally each year. Management strategies to control crown rot are limited and there are concerns about development of fungicide resistance so novel treatment strategies are desirable. A collection of endophytic Actinobacteria was screened for their ability to suppress the growth of F. pseudograminearum and the development of crown rot symptoms in wheat with the aim of identifying candidates that can be developed into biocontrol products. The ability of the Actinobacteria isolates to suppress the growth of three different F. pseudograminearum strains in vitro was assessed using agar-plate competition assays. Soil-free seedling assays were used to screen for suppression of development of early disease symptoms in the susceptible wheat (Triticum aestivum) cv. Tamaroi. Four of the isolates were tested in a glasshouse pot experiment to assess their ability to decrease disease symptoms and prevent yield losses in wheat cv. Tamaroi grown to maturity in an unsterilized soil. The screening of 53 isolates identified two Streptomyces isolates, MH71 and MH243, with very strong antifungal activity against F. pseudograminearum strains in agar-plate competition and seedling assays. In the glasshouse pot trial, plants treated with seed coatings of either MH71 or MH243 had > 24% lower disease severity than control plants infected with F. pseudograminearum. These two cultures show potential for development as biocontrol products because they are easy to culture, grow on relatively inexpensive media, produce highly durable spores and can be delivered to plants as a seed coat.

Biological Control of Strawberry Crown Rot Disease (Pestalotiopsis sp.) using Trichoderma harzianum and Endophytic Bacteria

Strawberry crown rot is one of the diseases caused by several soil-borne pathogens. Control of the disease is quite difficult, especially on unhealthy soil condition. The study was conducted to examine the potential of Trichoderma harzianum and consortium endophytic bacteria application to control strawberry crown rot disease and resistance of strawberry varieties to crown rot disease based on control treatment. The research stages were isolation and identification of the pathogen, antagonist test of T. harzianum against the pathogen, potency test of both biological control agents to control crown rot disease on three strawberry varieties (Dorit, Rosalinda and the hybrid of Early Bright and Tokii varieties). This study used a Randomized Block Design. The results indicated that Pestalotiopsis sp. was one of the pathogens causing strawberry crown rot. The pathogen was inhibited by T. harzianum using antagonistic mechanism. Although, based on the percentage inhibition of radial growth, only 32 % of inhibition of T. harzianum against Pestalotiopsis sp. when both isolates laid out on PDA in same time. Application of both biological controls lead to the increasing resistance of three strawberry varieties against crown rot disease. The hybrid of Early Bright and Tokii variety was the most resistant varieties compared than 2 others varieties after biological control application.

Biological control of strawberry crown rot, root rot and grey mould by the beneficial fungus Aureobasidium pullulans

Utilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.

Impacts of Paraffin Wax and Propolis on Controlling Crown Rot Disease and Maintaining Postharvest Quality of Banana

Crown rot disease is a major cause of losses during transportation, storage, and marketing of banana. In this study, the effects of paraffin wax, propolis extract and their combination on controlling crown rot disease and maintaining the quality of banana cv. Hom Thong were investigated. Crown of banana fruit were coated with 50% propolis, 100% paraffin wax and 100% paraffin wax combined with 50% propolis. Banana crown treated with 250 ppm prochloraz and non-coated fruit were used as the controls. All treatments were packed in corrugated box, stored at 13°C for 21 days (simulation for the transportation and storage) and then moved to ambient temperature for 6 days (simulation for the retail market). Results found that coating with paraffin wax combined with propolis showed the efficacy on controlling crown rot disease as same as using 250 ppm prochloraz. While coating with paraffin wax or propolis alone showed the incidence and severity of disease similar to non-coated fruit. Beside, coating with paraffin wax alone or combined treatment of paraffin wax and propolis could maintain some plant resistant mechanisms such as the content of total phenolic and the activity of phenylalanine ammonia lyase (PAL) in the crown of banana. For the quality of banana showed that coating with paraffin wax alone or the combination of paraffin wax and propolis were able to reduce weight loss, maintain firmness and color change of banana crown, and it did not affect to color change of peel and firmness of banana fruit.

Bioefficacy test of Hatake™ (Bacillus amyloliquefaciensD203 strain) for control of crown rot disease in ‘Cavendish’ bananas

Postharvest diseases of bananas remain a significant challenge of banana exporting countries and can result in considerable losses. Adequate storage and transportation facilities are among the strategies employed to reduce losses, but chemical control has been found to be more effective and economical. Synthetic fungicides have traditionally been used to mitigate postharvest diseases caused by harmful microorganisms. However, with current global health concern, there is a public desire to utilize eco-friendly alternatives to address decay loss. A study on the bioefficacy of a commercial formulation containing Bacillus amyloliquefaciens strain D203 (Hatake™) for control of crown rot disease in 'Cavendish' bananas, was conducted using both in vitro and in vivo screening techniques. Its potential in controlling crown rot and the efficacy of different rates were determined. Crown rot causing microorganisms were isolated and tested for antagonism by B. amyloliquefaciens strain D203. Efficacy was assessed through observations on its antagonistic properties, crown rot and mould severity, crown discoloration and peel colour changes. Laboratory analysis indicated that Colletotrichum musae was the dominant microorganism that colonized the petri plate which was further proved through pathogenicity tests. 1.0 g mL(‑1) of Hatake™ showed higher inhibitory zones against C. musae. Furthermore, an in vivo experiment showed that 1.0 g mL(‑1) rate of Hatake™ was more effective than 0.5 and 2.0 g mL(‑1) and synthetic chemical treatment in controlling crown rot and mould formation or production. A 1.0 g mL(‑1) rate of Hatake™ resulted in better crown colour among all fruit treated with 103 inoculum of C. musae mL(‑1) water. Development of fruit ripening, as manifested by its peel colour change, was significantly slower in fruits treated with 1.0 g mL(‑1) of Hatake™ compared to all treatments innoculated with 103 inoculum of C. musae mL‑1 water. The results indicated that Hatake™ has the potential for commercial application as postharvest treatment for 'Cavendish' bananas.

Characterization of Crown Rot Disease of Banana Fruit and Eco-Friendly Quality Improvement Approach during Storage

Introduction: The banana is the world’s most popular fruit crop. A complex of fungal pathogen is responsible for crown rot diseases of banana.&#x0D; Aims: The present study was designed to detect and characterize the crown rot disease of post-harvest banana (Musa paradisiaca) and also develop an alternative quality improvement approach to improve banana shelf-life during storage period.&#x0D; Study Design: A simplest general factorial experiment that was designed to control crown rot disease of banana using different biological factors, including plant extract, antagonistic agents and commercial fungicide.&#x0D; Place and Duration of Study: Disease infected bananas were collected from Rajshahi city, Rajshahi, Bangladesh in 2017 and the experiment had been conducted from April 2017 to April 2018.&#x0D; Methodology: Different morphological, biochemical and molecular techniques were used to characterize and detect the liable fungi. Responsible fungi were subjected to antifungal activity screening test and in vitro antagonism test. Effect of carbendazim and kanamycin B against the mycelial growth of the isolates was determined by disc diffusion method. Quality parameters including disease incidence and severity, pH, TSS, TTA and AA of the treated banana were also analyzed after application of treatments in the packing stage through standard estimation techniques.&#x0D; Results: Two fungi, isolated from the infected portion were further identified as C. musae and L. theobromae. D. metel and A. sativum extract was better in inhibiting mycelial growth of all the test pathogen in culture. B. cereus and T. harzianum moved and attached to fungal isolates, affecting mycelial growth and A. sativum extract significantly affecting conidial germination on artificial medium. Satisfactory mycelia inhibitory effect was recorded from kanamycin B. Quality analysis after storage of banana showed minor measurable differences among treatments.&#x0D; Conclusion: Post-harvest application of A. sativum extract (Conc. 25% w/v) improve the overall quality of harvested banana fruits and reduced the disease incidence and severity of crown rot to a level significantly lower than in fungicide treated or control fruits.

Control of Postharvest Crown Rot Disease in Cavendish Banana with Aluminium Sulfate and Vacuum Packaging

Effect of alum in combination with vacuum packaging was investigated in controlling crown rot disease of Cavendish banana (Musa acuminata, AAA, Grande Naine cultivar) at 12-14 oC. Twelve week mature Cavendish banana fruits were treated with 1% (w/v) alum (Potassium aluminium sulphate), 0.5 g/L carbendazim (Positive control) or distilled water (Negative control). Treated banana samples were packed in Low Density Polyethylene bags (150 gauge) and stored at 12-14 oC. In-package gases were analysed every seven days up to 28 days of storage. Physicochemical properties (pH, firmness, TSS, TA), sensory properties (peel colour, flesh colour, aroma, flavour, taste, overall acceptability) and crown rot disease severity were determined in ripening induced fruits after each storage period. Data obtained for physicochemical properties and in-package gases were subjected to ANOVA whereas pathological and sensory properties were analysed using Kruskal-Wallis non-parametric statistical test using Minitab. At the end of 28 days of storage, O2 in all packages remained between 5.6-5.8% while CO2 remained between 5.0 to 5.1%. Further, treatment of 1% alum alone controlled crown rot disease completely up to 14 days. Most of physicochemical and sensory properties of treated banana were not adversely affected by the treatment.

Basil oil plus aluminium sulfate and modified atmosphere packaging controls Crown rot disease in Embul banana (Musa acuminata, AAB) during cold storage

Effect of basil oil spray treatment in combination with modified atmosphere packaging was investigated in controlling crown rot and extending the shelf life of Embul banana (Musa acuminata, AAB) at 12–14°C. Embul banana fruits were treated with 1% aluminium sulfate, 1% aluminium sulfate+0.4% basil oil and distilled water (control). Treated banana samples were packed in Low Density Polyethylene bags and stored at 12–14°C. In-package gases were analysed after 14days of cold storage. Physicochemical properties, nutritional properties, sensory properties and crown rot disease severity as well as residues in treated banana peel were determined in ripening induced fruits. Test marketing trials were conducted in fruit outlets in Dambulla and Kiribathgoda, Sri Lanka where treatments were provided to consumers and staff to obtain feedback on the quality of treated banana. At the end of 14days, O2 in packages remained between 3.1–3.7% while CO2 varied from 4.2 to 4.7%. 1% aluminium sulfate+oil treatment significantly controlled crown rot disease compared to others. Most of the physicochemical, sensory properties of aluminium sulfate+basil oil treated banana were not significantly different compared to control whereas nutritional properties of treated samples showed no drastic changes compared to control. Treated samples scored higher for peel colour and taste over control samples, by staff and consumers of fruit outlets. Consumers preferred basil oil treated banana over untreated due to their sweet and pleasant taste. Insignificant amount of residues persisted in treated banana. This current safe, eco-friendly treatment strategy could be recommended in preparing Embul as well as other banana varieties belonging to Musa acuminata, AAB group for commercial scale export to various destinations which require a transit time of two weeks.

Vacuum Packaging Controlled Crown Rot of Organically-Grown Balangon (Musa acuminata AAA Group) Banana

Balangon bananas take about 23 to 28 days from harvest to reach Japan since the fruit have to be assembled from small and scattered farms, hence the problems of premature ripening and crown rot. The effectiveness of vacuum packaging in retarding ripening and in controlling crown rot has not been documented for organically-grown Balangon bananas. Balangon bananas harvested from farms in Don Severino Benedicto, Negros Occidental, Phillipines, were washed three times in tap water, then packed (wet packing) in a 13-kg capacity corrugated fibreboard carton lined with 0.05 mm thick low density polyethylene (LDPE) bag, and vacuum-packed using an ordinary vacuum cleaner. Bananas treated with 1% sodium bicarbonate were also subjected to vacuum packing. Packaged bananas were then loaded in refrigerated vans (13.0–13.5 °C), transported to Manila and then to the UPLB-PHTRC laboratory for simulated domestic and international shipments which took about 25 days from harvest until the bananas reached Japan. Bananas were then taken out of the sealed LDPE, allowed to equilibrate at 18 °C, treated with 2500 µL/L ethephon, and held at 23 °C for ripening. During the 25-day holding at 13.0–13.5 °C, bananas that were vacuum-packaged remained green. In the control (not vacuum-packaged), a few fingers in each hand started to ripen. The most significant effect of vacuum packaging in combination with 13 °C storage was the control of crown rot, particularly when bananas started to ripen. With vacuum packaging, the incidence of crown rot at the ripe stage was 2.8% compared with 55.7% in the control. Sodium bicarbonate did not control crown rot alone, nor contribute to the reduction caused by packaging and vacuum associated with the control of decay was the high visual quality rating of the fruit. Extended storage under vacuum-packed conditions did not significantly affect the physico-chemical and sensory attributes of bananas at the ripe stage.

Managing Phytophthora crown and root rot on tomato by pre-plant treatments with biocontrol agents, resistance inducers, organic and mineral fertilizers under nursery conditions

Five trials were carried out under greenhouse conditions to test the efficacy of spray programmes based on biocontrol agents, phosphite-based fertilizers and a chemical inducer of resistance (acibenzolar-S-methyl, phosethyl-Al) to control crown and root rot of tomato incited by Phytophthora nicotianae . The best disease control, under high disease pressure resulting from artificial inoculation, was obtained with three pre-plant leaf sprays at 7 d intervals with acibenzolar-S-methyl and with two mineral phosphite-based fertilizers. The disease reduction achieved was similar to that obtained with a single application of azoxystrobin and metalaxyl-M. Phosetyl-Al and the biocontrol agents Glomus spp. + Bacillus megaterium + Trichoderma , B. subtilis QST713, B. velezensis IT45 and the mixture T. asperellum ICC012 + T. gamsii ICC080 provided a partial disease control. Brassica carinata pellets did not control the disease.

Post-harvest treatments for controlling crown rot disease of Williams banana fruits (Musa acuminata L.) in Egypt

Fusarium semitectum was isolated at high frequency from collected banana cultivar Williams showing crown rot symptoms from commercial markets. The inhibitory effect in vitro of tested essential oils on mycelium growth was higher than on conidium germination of F. semitectum. Complete inhibition of fungal growth and spore germination was recorded at the concentration of 1.0% of tested cinnamon and bitter almond oils. Under storage conditions, artificially inoculated bananas showed reduction in both crown rot disease incidence and severity when treated with cinnamon, thyme bitter and sweet almond oils. Complete reduction (100.0%) of crown rot disease incidence of banana fruits was recorded at the concentration of 4.0% of applied cinnamon and thyme oils, followed by sweet almond and bitter almond oils which they reduced disease incidence by 87.1 and 78.7%, respectively. Stored bananas treated with cinnamon, bitter and sweet almond oils showed no significant differences compared to the control with respect to odour, flavour, taste and overall acceptability. Hence cinnamon, thyme, bitter and sweet almond oils treatment developed during the current study without affecting the organoleptic properties recommended as a safe and cost-effective commercial method for treating bananas to control crown rot disease.

IN VITRO MANAGEMENT OF CROWN ROT DISEASE OF BANANA (MUSA SPP. AAA) 'MEDIUM CAVENDISH' USING EXTRACTS FROM OCIMUM GRATISSIMUM, ALSTONIA BOONEI AND GARCINIA KOLA

A study was conducted to assess the potential of extracts from Ocimum gratissimum, Alstonia boonei and Garcinia kola to control crown rot disease in banana. Colletotrichum musae, Botryodiplodia theobrome, Fusarium moniliforme and Fusarium oxysporum were isolated from diseased crown rot tissues from fruits collected from the forest eco-zone of Ghana and used for this experiment. Each of the isolates singly, or in combination, was able to cause crown rot disease when inoculated into healthy banana crowns. In a bioassay, crude extract from leaves of Ocimum gratissimum showed consistent fungicidal activity against all four fungal isolates by producing zones of inhibition against them at 100 and 75% concentration. Garcinia kola showed fungicidal activity against Colletotrichum musae, Fusarium moniliforme and Fusarium oxysporum at 75 and 100% concentration while Alstonia boonei did not show any fungicidal activity against any of the fungal isolates.