Geographical Distribution and Genetic Diversity of the Banana Fusarium Wilt Fungus in Laos and Vietnam

Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense (Foc), poses a major threat to global banana production. The tropical race 4 (TR4) variant of Foc is a highly virulent form with a large host range, and severely affects Cavendish bananas. Foc TR4 was recently observed within the Greater Mekong Subregion, after Chinese private companies expanded Cavendish production to the region. In this study, extensive surveys conducted across Laos and Vietnam show that Foc TR4 is still mainly constricted to the northern regions of these countries and is limited to Cavendish cultivation settings. In Laos, Foc TR4 is associated with large-scale Cavendish plantations owned by or involved with Chinese companies through which infected planting material could have been imported. In Vietnam, mostly small-holder Cavendish farmers and backyard gardens were affected by Foc TR4. In Vietnam, no direct link is found with Chinese growers, and it is expected the pathogen mainly spreads through local and regional movement of infected planting materials. Foc TR4 was not recorded on banana cultivars other than Cavendish. The extensively cultivated ‘Pisang Awak’ cultivar was solely infected by VCGs belonging to Foc race 1 and 2, with a high occurrence of VCG 0123 across Laos, and of VCG 0124/5 in Vietnam. Substantial diversity of Foc VCGs was recorded (VCGs 0123, 0124/5, 01218 and 01221) from northern to southern regions in both countries, suggesting that Fusarium wilt is well established in the region. Interviews with farmers indicated that the local knowledge of Fusarium wilt epidemiology and options for disease management was limited. Clear communication efforts on disease epidemiology and management with emphasis on biosecurity practices need to be improved in order to prevent further spread of Foc TR4 to mixed variety smallholder settings.

FoQDE2-dependent milRNA promotes Fusarium oxysporum f. sp. cubense virulence by targeting a glycosyl hydrolase coding gene at transcriptional level

MicroRNAs (miRNAs) are small non-coding RNAs that regulate protein-coding gene expression primarily found in plants and animals. Fungi produce microRNA-like RNAs (milRNAs) that are structurally similar to miRNAs and functionally important in various biological processes. The fungus Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of Panama disease that threatens global banana production. It remains uncharacterized about the biosynthesis and functions of milRNAs in Foc. In this study, we investigated the biological function of milRNAs contributing to Foc pathogenesis. Within 24 hours post infecting the host, the Argonaute coding gene FoQDE2, and two Dicer coding genes FoDCL1 and FoDCL2, all of which are involved in milRNA biosynthesis, were significantly induced. FoQDE2 deletion mutant exhibited decreased virulence and hypersensitivity to hydrogen peroxide (H2O2). These results indicate that milRNA biosynthesis is crucial for Foc pathogenesis. By small RNA sequencing, we identified 364 small RNA-producing loci in the Foc genome, 25 of which were significantly downregulated in the FoQDE2 deletion mutant, from which milR-87 was verified as a FoQDE2-depedent milRNA based on qRT-PCR analysis. Through deletion and overexpression of milR-87 in the wild-type Foc strain, functions of milR-87 were studied. The results showed that milR-87 is crucial for Foc virulence in infection process. We furthermore identified a glycosyl hydrolase-coding gene, FOIG_15013, as the direct target of milR-87. The FOIG_15013 deletion mutant displayed a dramatic increase in the growth, conidiation and virulence. Transient expression of FOIG_15013 in Nicotiana benthamiana leaves activates the host defense responses. Collectively, this study documents the involvement of milRNAs in the manifestation of the devastating fungal disease in banana, and demonstrates the importance of milRNAs in the pathogenesis and other biological processes. Further analyses of the biosynthesis and expression regulation of fungal milRNAs may offer a novel strategy to combat devastating fungal diseases.Author summaryThe fungus Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of Panama disease that threatens global banana production. As a typical representative of F. oxysporum species complex, the pathogen has been widely concerned. However, pathogenesis of Foc is not fully elucidated. In particular, pathogenic regulatory mechanism of the microRNA like small RNAs (milRNAs) found in Foc is unknown. Here, we found that FoQDE2, one Argonaute coding gene, and two Dicer coding genes FoDCL1 and FoDCL2, which are involved in milRNA biosynthesis, are significantly induced during the early infection stage of Foc. The results suggested that the milRNAs biosynthesis mediated by these genes may play an active role in the infection process of Foc. Based on this assumption, we subsequently found a FoQDE2-dependent milRNA (milR-87) and identified its target gene. Functional analysis showed that FoQDE2, miR-87 and its target gene were involved in the pathogenicity of Foc in different degree. The studies help us gain insight into the pathogenesis with FoQDE2, milR-87, and its target gene as central axis in Foc. The identified pathogenicity-involved milRNA provides an active target for developing novel and efficient biocontrol agents against Panama disease.

Modeling, structural and cfd analysis of mobile robot for banana cultivation

The banana plantation is a popular cash crop in southern parts of India. Globally, India ranks first in banana production by producing about 14 million metric tons annually. Cultivation of which involves humongous manual tasks with moderate difficulty, often the tasks are accompanied by considerable spending towards accomplishing those tasks. More often than not it affects the earning prospects of the farmer thus, succumbing to a great loss of investment. A valid solution to this problem from the technological perspective is to provide low-cost automation for the hectic tasks in banana cultivation. Through this work, a baby step towards addressing the issues in banana cultivation is initiated. This paper deals with the design, structural, computational fluid dynamics simulation of an Agricultural field robot for aiding banana cultivation by producing a plantation hole for banana seedlings. The conceptualized idea is modeled in 3dimension using SolidWorks software with suitable dimensions, then by applying desired material properties to the individual components a static structural analysis is executed on the assembly. After the completion of structural analysis, subsequently, CFD analysis is carried out with an Ansys-Fluent workbench on the equivalent solid modal replica of the assembly modal, developed exclusively to analyze the wind effects.

Separate and Joint Interests: Understanding Gendered Innovation Processes in Ugandan Farm Systems

Agricultural innovation is considered paramount in solving poverty, food insecurity and malnutrition in the global south and notably in the East-African highlands. However, processes of change surrounding innovation in agriculture, and potential gender differences in their impacts, are often poorly understood. This paper resorts to principles from Farming Systems Research (FSR) and social gender analysis to study agricultural innovation processes and increase the understanding of the differential ways men and women engage with and are impacted by agricultural innovation(s). We analyze qualitative data from six Focus Group Discussions conducted in each of the two study communities located in Central and Western Uganda. These data focus on the most important agricultural innovations as perceived and assessed by men and women in their community. We list and discuss these most important innovations and further zoom in on one innovation per site: “Use of herbicides in maize production” in Central Uganda and “New agronomic practices for intensified highland banana production” in Western Uganda. Results clearly show that women's and men's domains are not separated as superficially might appear. Women and men have both separate and joint interests and adoption of an innovation by one gender, will affect the other too. The effects are multifold, with positive and negative elements. Women's ability to innovate is constrained as compared to men because gender norms limit women's agency in relation to mobility and financial independence amongst others. The two innovations studied were found to alter some gender roles and relations but did not unambiguously contribute to increasing gender equality.

Economics of Banana Production in Solapur District of Maharashtra, India

The study analyses the resource-use efficiency of banana cultivation in relation with per ha return and cost based on the information of 90 sample farmers of Solapur district, Maharashtra in 2018-19. Findings show that production level was 563.11q/ha on an aggregate level. The estimated cost of cultivation was Rs.324671.04/ha. The per hectare inputs utilized for banana at overall level were 118.58 human days, 22.67 tonnes manures, 399.60 kg N, 126.11 kg P, 720.29 kg K. Average gross income was Rs.627708.57. The gross income received in size group small, medium and large was Rs. 609142.70, Rs. 614926.70 and Rs.659056.30, respectively. The benefit-cost ratio was 1.93 at the overall level indicating highly prosperous crop. This ratio is the highest (2.06) for large size farms. Thus, the crop was found to be economically viable. The results of Cobb-Douglas production function howed that seed, manures, potassium fertilizer and irrigation had positive and significant influence on the yield of banana. The magnitude of coefficient of multiple determination (R2) was 0.92. Value of the ratio of MVP/Px was found greater than unity in case of seed, manures and irrigation indicated the underutilization of these resources. Quantity of per hectare produce marketed was maximum (99.09 per cent) for large size group and minimum in (98.88 per cent) for small size group i.e. there is no significant differences as marketing system was similar.

Adoption of banana (Musa spp) production technology among small-scale farmers in Embu West Sub-County, Kenya

The study examined adoption of recommended banana production technology among small-scale farmers in Embu West Sub-County, Kenya. Data were obtained from a sample of 384 small-scale banana farmers that were proportionately selected from four wards of the study area. A structured interview schedule was used for data collection. Both percentages and inferential statistics were employed in data analysis. The study used a logarithmic multiple linear regression model based on Cobb-Douglas production function. The amount of credit accessed, cost of the banana plantlets, fertilizer and manure had significant effects on banana output area. In addition, adoption of tissue culture banana, use of irrigation, debudding, desuckering, deleafing and banana value addition had positive and significant effects on banana production. The County government to enhance sensitization of small-scale banana farmers on the importance of adopting these and other recommended technologies for improved banana yields.

Study of Bunchy Top of Banana Virus (BBTV) and its Control by Integrated Disease Management (IDM)

India is the top country by Banana production in the world as of 2019, bananas production in India was 30.5 million tonnes that accounts for 26.02% of the world's bananas production. The top 5 countries (others are China, Indonesia, Brazil, and Ecuador) account for 53.94% of it. The world's total bananas production was estimated at 117 million tonnes in 2019.In India, states like Andhra Pradesh, Gujarat, Tamil Nadu, Maharashtra, Kerala, Uttar Pradesh, Bihar and Madhya Pradesh contribute more than 70 per cent of the country's banana production. Banana and plantain (Musa spp.), produced in 10.3 million ha in the tropics, are among the world's top 10 food crops. They are vegetative propagated using suckers or tissue culture plants and grown almost as perennial plantations. They are vulnerable to pests and pathogens, especially viruses which causes reduction in yield and are also hinders to the international exchange of germplasm. The most economically important viruses of banana and plantain are Banana bunchy top virus (BBTV), a complex of banana streak viruses (BSVs) and Banana bract mosaic virus (BBrMV). BBTV is known to cause the most serious economic losses contributing to yield reduction of up to 100% and responsible for a dramatic reduction in cropping area. The BSVs exist as episomal and endogenous forms are known to be worldwide in distribution. In India and the Philippines, BBrMV is known to be economically important.

An Economic Analysis on Production of Hill Banana in Dindigul District of Tamil Nadu, India

This study was primarily concentrated on hill banana cultivation. The purpose of this study is to find the economics of hill banana cultivation and the problems faced by the hill banana farmers during the production of hill bananas in the Dindigul district of Tamil Nadu. Economics of the hill banana cultivation was done by finding the cost and returns associated with the hill banana cultivation and constraints faced by the hill banana farmers with Garrett's ranking technique. Many previous research on the production of various agricultural commodities was focused on a specific area and/or a specific commodity. There was a little study on banana production and limitations in some regions in Tamil Nadu. As a result, the focus of this research will be on hill banana production in the Dindigul district. Purposive and convenience sampling technique was used in this study. Primary data were collected by the personal interview with a well-structured interview schedule. The cost and returns of hill bananas were calculated per hectare. The average cost of production of hill bananas was estimated to be ₹2.04 lakh/ha. The average gross return was ₹5.04 lakh/ha and the average net return was estimated to be ₹2.99 lakh/ha. The result of the study shows that hill banana cultivation was highly profitable and the benefit-cost ratio (BC Ratio) was more than unity (2.46). The major constraints faced by hill banana farmers in the cultivation of hill bananas were pest attack (insects) followed by disease attack, lack of labor availability, animal attack, and drought. The findings will assist policymakers in developing appropriate programs and adjusting strategies for improving hill banana production in Tamil Nadu.

Oligosaccharides production by enzymatic hydrolysis of banana pseudostem pulp

Banana production generates significant amounts of agricultural wastes, being fiber extraction one of the most relevant alternatives for their valorization. This process produces banana’s pseudostem pulp (BPP) as a byproduct, which shows an interesting composition for the biorefinery’s biochemical platform, with high polysaccharides (68%) and low lignin contents. This work deals with the enzymatic hydrolysis (EH) of raw and hydrothermally pre-treated BPP, focusing on the production of oligosaccharides (OS). Raw BPP hydrolysis with cellulase at different dosages rendered only 3.2% OS yields (OSY). Pectinase addition has not affected EH performance. On the other hand, EH of hydrothermally pre-treated BPP at 150 °C and 170 °C (P150 and P170) allowed to increase OSY up to 28% (P150, 1 FPU of cellulase/g dry biomass, 12 h), being 72% of the solubilized sugars in the form of cello-oligosaccharides. This last condition was subjected to a multi-stage EH strategy without improvements in OSY. An endo-glucanase was also tested, but obtained OSY were lower than cellulase results. Finally, obtained OS demonstrated to stimulate the growth of two Lactobacilli strains. The results show that BPP pre-treated under mild operational conditions is a good candidate for cello-oligosaccharides production by EH using 1 FPU/g DB of cellulase with a simple strategy. Graphical abstract

Susceptibility of the banana inflorescence to Blood disease

The bacterium Ralstonia syzygii subsp. celebesensis causes Blood disease of banana, a vascular wilt of economic significance in Indonesia and Malaysia. Blood disease has expanded its geographic range in the last 20 years and is an emerging threat to Southeast Asian banana production. Many aspects of the disease cycle and biology are not well understood, including the ability of different parts of the female and male inflorescence of banana to act as infection courts. This study confirms that the banana varieties of Cavendish, and Kepok ‘Kuning’ are susceptible to Blood disease and that an inoculum concentration of 102 CFU.mL-1 of R. syzygii subsp. celebesensis is adequate to initiate disease following pseudostem inoculation. Data show that infection occurs through both the male and female parts of a banana inflorescence and the rachis when snapped to remove the male bell. The infection courts are the female flowers, the male bell bract scar, the male bell flower cushion, the snapped rachis, and deflowered fingers. The location of these infection courts concurs with the dye studies demonstrating that dye externally applied to these plants parts enters the plant vascular system. Thus, the hypothesis is supported that infection of R. syzygii subsp. celebesensis occurs through open xylem vessels of the male and female parts of the banana inflorescence.