Application of UAV Remote Sensing in Monitoring Banana Fusarium Wilt

Fusarium wilt poses a current threat to worldwide banana plantation areas. To treat the Fusarium wilt disease and adjust banana planting methods accordingly, it is important to introduce timely monitoring processes. In this chapter, the multispectral images acquired by unmanned aerial vehicle (UAV) was used to establish a method to identify which banana regions were infected or uninfected with Fusarium wilt disease. The vegetation indices (VIs), including the normalised difference vegetation index (NDVI), normalised difference red edge index (NDRE), structural independent pigment index (SIPI), red-edge structural independent pigment index (SIPIRE), green chlorophyll index (CIgreen), red-edge chlorophyll index (CIRE), anthocyanin reflectance index (ARI), and carotenoid index (CARI), were selected for deciding the biophysical and biochemical characteristics of the banana plants. The relationships between the VIs and those plants infected or uninfected with Fusarium wilt were assessed using the binary logistic regression method. The results suggest that UAV-based multispectral imagery with a red-edge band is effective to identify banana Fusarium wilt disease, and that the CIRE had the best performance.

The effect of method and dosage application of biofungicide extract of Legundi leaf fermented with Trichoderma harzianum fungus for control of Fusarium wilt disease on shallots

Legundi weed (Vitex trifolia) has the potential to be used as a biofungicide to control Fusarium wilt disease on shallots. For the manufacture of biofungoicides, legundi leaf extract was first fermented using the fungus Trichoderma harzianum. The aim of this study was to determine the effect of the method and dose of fermented Legundi leaf extract biofungicide on the Fusarium fungus that causes shallots wilt. The research was carried out in Senteluk Village, Batu Layar District, West Lombok Regency using an experimental method with a factorial randomized block design with two factors. As the main effect, namely the application of biofungicide fermented Legundi leaf extract consisting of two levels, namely: seed treatment before planting, and spraying treatment for plants aged 7 days after planting. Meanwhile, the simple effect is the application dose of fermented Legundi leaf extract biofungicide consisting of 5 levels, namely: 0.00 mL, 2.50 mL; 5.00 mL; 7.50 mL and 10.00 mL. The combination method and dose of fermented Legundi leaf extract biofungicide was repeated three times each, so there were 30 treatment combinations. The results obtained were the application of Legundi leaf extract biofungicides by soaking the seeds before planting at a starting dose of 2.50 mL to effectively control onion wilt disease. The applied biofungicide can increase plant height and increase the dry weight of the harvest.

Biodiversity of Trichoderma antagonist saprophytic fungi and its use for biocontrol of Fusarium wilt disease on shallots at Lombok Island, West Nusa Tenggara, Indonesia

One of the obstacles in the development of shallots in West Nusa Tenggara (NTB) is the presence of Fusarium wilt disease. The use of antagonistic saprophytic fungi Trichoderma spp. is a biological control technique. The aim of this research is to explore the biodiversity of Trichoderma spp. and its use for controlling Fusarium wilt disease. Research using exploratory methods conducted at the shallot planting center on Lombok Island included isolation of antagonistic saprophytic fungi, purification and identification of isolates. Furthermore, research was carried out in the laboratory using experimental methods including in-vitro antagonism tests by direct opposition and culture steam. The research was continued in Greenhouses in planta and in field conditions in the Highlands of Sembalun Village, Medium Plains of Santong Village and Senteluk Village Lowlands. The results concluded that: there were 6 isolates of saprophytic fungi that were antagonistic, namely T. viride, T. longibrachiatum, T. koningii, T. piluliferum, T. harzianum, and T. hamatum. The mechanism of antagonism is physically through space competition, mycoparasites and antibiosis. Three isolates, namely T. virede, T. harzianum and T. hamatum, were effective in suppressing Fusarium wilt disease and even causing immunity.

Effect of Biological Fertilizer and Chemical Fungicide on Fusarium Wilt Disease, Growth and Yield on Onion (Allium ascaloncum L)

Onion (Allium Ascalonicum L) are one of the leading horticultural commodities that have economic value. In cultivation, Fusarium wilt disease is often damaged caused by the fungus Fusarium oxysporum. This study aimed to examine the effect of biofertilizer application on fusarium wilt disease, growth and yield of onion. The treatments tested were Bion-up biofertilizer, KIBRT, Biostimulant, Azoto-Tricho, anthracol fungicide, and without biological fertilizer as a control. Using a randomized block design with three replications. Observation variables were the incidence of fusarium wilt disease, plant height, number and weight of tubers. The results showed that the application of biofertilizers (Bion up, KIBRT, Biostimulants and Azoto-Tricho) was effective in increasing plant height, number of bulbs, and bulb weight of onion bulbs, while controlling the development of fusarium wilt disease was more effective when using Bion up, KIBRT, and Azoto-Tricho.Keywords: Biofertilizer, Antracol, Shallots, Fusarium oxysporum

Evaluation of Trichoderma asperellum B1902 in Controlling Fusarium Wilt of Cavendish Banana Cultivar

Trichoderma species is one of the microorganisms with antagonistic properties as biological control agents. In the banana industry, Fusarium wilt disease caused by Fusarium oxysporum f. sp. cubense (Foc) has been practically managed using chemical pesticides that led to environmental disruptions, ineffective conditions and disease resistance. In preliminary study, T. asperellum gave better result compared to other species in inhibiting the growth of Foc in in vitro condition. Therefore, the aim of this study was to examine the effects of T. asperellum as a biological control of Fusarium wilt disease of banana. A total of 326 fungal isolates were isolated from soil samples obtained around Malaysia and identified as Trichoderma species based on phenotype characteristics. The species identity for the best candidates from dual culture test was confirmed based on internal transcribed spacers (ITS) and translation elongation factor 1 alpha (TEF-1α) sequence identity. In dual culture test, findings showed that three isolates with a high percentage inhibition of radial growth (PIRG) were observed in plates of T. asperellum isolates B1902 (84.85%), T2007 (77.78%) and C1667 (75.76%), which successfully inhibited the growth of F. oxysporum f. sp. cubense isolate 9888. Based on in vivo test, the best candidate was T. asperellum B1902 with lower disease severity index (DSI) value of 0.2 compared to the inoculated control with DSI of 3.6. As a conclusion, T. asperellum B1902 can be used as an alternative treatment in managing Fusarium wilt disease. Hence, future study should be focused on applying T. asperellum as a biocontrol agent in the field and controlling other plant diseases in the agricultural plantation.

Trichoderma atroviride LZ42 Releases Volatile Organic Compounds Promoting Plant Growth and Resisting Fusarium wilt Disease in Tomatoes

The promotion of plant growth and suppression of plant disease using beneficial microorganisms is considered an alternative to the application of chemical fertilizers or pesticides in the field. In this study, a coconut-scented antagonistic Trichoderma strain LZ42, previously isolated from Genoderma lucidum-cultivated soil, was investigated for biostimulatory and biocontrol functions in tomato seedlings. Morphological and phylogenetic analyses suggested that strain LZ42 is closely related to T. atroviride. Tomato plants showed increased aerial and root dry weights in greenhouse trials after treatment with T. atroviride LZ42 formulated in talc, indicating the biostimulatory function of this fungus. T. atroviride LZ42 effectively suppressed Fusarium wilt disease in tomato seedlings, with an 82.69% control efficiency, which is similar to that of fungicide treatment. The volatile organic compounds (VOCs) emitted by T. atroviride LZ42 were found to affect the primary root growth direction and promote the root growth of tomato seedlings in root Y-tube olfactometer assays. The fungal VOCs from T. atroviride LZ42 were observed to significantly inhibit F. oxysporum in a sandwiched Petri dish assay. SPME-GC-MS analysis revealed several VOCs emitted by T. atroviride LZ42; the dominant compound was tentatively identified as 6-pentyl-2H-pyran-2-one (6-PP). 6-PP exhibited a stronger ability to influence the direction of the primary roots of tomato seedlings but not the length of the primary roots. The inhibitory effect of 6-PP on F. oxysporum was the highest among the tested pure VOCs, showing a 50% effective concentration (EC50) of 5.76 μL mL-1 headspace. In conclusion, T. atroviride LZ42, which emits VOCs with multiple functions, is a promising agent for the biostimulation of vegetable plants and integrated management of Fusarium wilt disease.

A Novel Antifungal Actinomycete Streptomyces sp. Strain H3-2 Effectively Controls Banana Fusarium Wilt

Banana Fusarium wilt disease caused by Fusarium oxyspoum f. sp. cubense (Foc) seriously threatens the banana industry. Foc tropical race 4 (Foc TR4) can infect almost all banana cultivars. Compared with traditional physical and chemical practices, biocontrol strategy using beneficial microbes is considered as an environmentally sound option to manage fungal disease. In this study, a strain, H3-2, isolated from a non-infected banana orchard, exhibited high antifungal activity against Foc TR4. According to its morphological, physiological, and biochemical characteristics, the strain H3-2 was identified as Streptomyces sp. and convinced by the polymorphic phylogenic analysis of 16S rRNA sequences. Extracts of the strain H3-2 suppressed the growth and spore germination of Foc TR4 in vitro by destroying cell membrane integrity and mycelial ultrastructure. Notably, the strain and its extracts showed broad-spectrum antifungal activity against the selected seven fungal phytopathogens. Fourteen chemical compounds in the extracts were identified by gas chromatography–mass spectrometer (GC-MS), primarily phenolic compounds. Additional pot inoculation experiment demonstrated that the fermentation broth of the strain H3-2 promoted the growth of banana seedlings by efficiently inhibiting the spread of banana Fusarium wilt disease. This study demonstrated the potential application of the novel Streptomyces sp. H3-2 for the management of banana Fusarium wilt.