Experts study banana disease in Tanzania

04Apr 2020
Crispin Gerald
The Guardian
Experts study banana disease in Tanzania

RESEARCHERS are challenges against banana wilt disease’ that affects the growth of banana, a major source of food and income for millions of small holder farmers.

The disease called ‘fusarium wilt’, a soil borne fungal is being spread by the fungus called fusarium oxysporum fsp Cubense (Foc). It enters the roots systems of banana plants and blocks the uptake of nutrients and water.

The research is conducted by researchers from the International Institute for Tropical Agriculture (IITA) and the CGIAR research program on roots, tubers and banana (RTB).

The disease causes yellowing of leaves, splitting of the pseudosten, and eventual death of the banana plant.

It is difficult to control as it cannot be managed by synthetic pesticides/fungicides and therefore continues to spread easily as farmers exchange planting materials (banana suckers), water and movement of people and equipment.

A statement issued by IITA yesterday in Dar es Salaam said all traditional East Africa highland cooking bananas including Mchare in Tanzania and some desert bananas like Sukari Ndizi are susceptible to this disease.

However, it was observed that only some of the plants die after infection.

The researchers sought to understand why this is so by studying the microorganisms bacteria and fungi, surrounding the roots as well as in the roots and corn. This is known as the soil microbiome.

Systems agronomist for IITA who led the study, Manoj Kaushal said: “This study allowed us to have a better understanding of the root microbiome in banana that can be harnessed to develop new disease management tools in Mchare based on beneficial microorganisms (endophytes and biological control agents) for smallholder farmers in sub-Saharan Africa”.

The researchers suspect that the interaction between the soil microbiome and the banana plant may provide some defense against the fungal pathogen. And if this is the case, this may pave the way for the development of bio-control products to protect banana against the disease using soil microorganisms.

In their research, they were able to establish a link between the levels of microbiome diversity with the plants resistance to the invasion of the pathogen in the roots.

The researchers profiled the root microbiome of banana both with and without symptoms of the disease. Each sample showed substantial differences in the community composition and species abundance.

The beneficial bacteria identified in the root samples included actinomycetales which are known to produce various metabolic compounds that helps to suppress various plant and soil borne pathogens.

Others were pseudomonadales, well-known to be responsible for beneficial plant-microbe interactions, and streptomycetaceae, which are known to produce antagonist compounds against various plant pathogens.

The institute said future research will be focused on the isolation, characterization, and screening of various indigenous microbial strains with the target to develop a product from the microbial strains (single or consortium) that will provide enhanced tolerance against banana Fusarium wilt disease to boost the production of banana in the region.

The IITA banana research program aims to improve soil health and increase the yields of the EAHB more sustainably.