Potatoes play a large role in the East African agricultural economy. In Kenya alone, the root vegetable makes up more than US$500 million of the local agricultural economy and is responsible for creating 2.5 million jobs. However, the region has been plagued by a devastating pest called the potato cyst nematode (PCN). There is a glimmer of hope though in the form of banana plant waste material which can be used to form a protective barrier.
What very few know is that potatoes are endemic to South America, and were brought to other countries by early trade. The potatoes did not arrive alone however, as they were followed by the destructive PCN.
The pest was first discovered in Kenya in 2015, and it has since expanded throughout the country’s key potato-growing regions, as well as Rwanda and Uganda.
A pest that knows no boundaries
“Potato cyst nematode is considered to have originated from the Andes region of South America, from where it spread to Europe with potatoes. The ease with which it has been transported across continents proves what a resilient pest it is. The cyst form which adheres to host roots, stolons and tubers and to soil particles during transportation, gives rise to new infestations where climate and food source are both available and favourable,” according to the agricultural organisation CABI.
“The life cycle takes approximately 45 days, during which time the males will moult and become vermiform, leave the host root and fertilise as many females as possible before dying about 10 days or so after first leaving the root. The females during this time have become saccate and their posterior ends have protruded through the root cortex, ready for mating.
“Recent observations show that one of the free radicals produced by plants is in the form of hydrogen peroxide, which is produced in response to nematode invasion, and is in all probability broken down by an enzyme secreted by the nematode’s surface coat, thioredoxin peroxidase.”
“Various other proteins have been identified from the surface coat and hypodermis of the nematode, such as the lipid binding protein GpFAR-1. This probably plays a role in the host defence signalling pathways as other plant parasitic nematodes, but not free-living types, also have similar compounds in their genetic makeup. Plant parasitic nematodes have probably evolved similar methods with which to protect and help to conceal themselves from the host plant,” CABI added.
The introduction of banana paper
An organic approach created from banana plant waste material is believed to be the final cure to the PCN pest, which is endangering East Africa’s potato output. Before planting, the “wrap and plant” method involves wrapping potato seeds in a thick, absorbent paper made from banana plant fibre. By building a protective barrier around the plants, this method shields them from PCN damage.
The wrap-and-plant paper is able to soak up and physically bind the essential chemical signals generated by potato crops that allow the PCN to hatch, find, and infect the plant’s roots through a process called hydrogen bonding.
As banana paper is made of the pulp of banana skins, it is biodegradable and a sustainable choice in the fight against the nematode.
What else can bananas be used for?
According to a 2014 NCBI study, “banana by-products have been used for wrappings foods, clothes and used in various ceremonial occasions and the usage expands through cultural diversification. Modern agriculture generally groups banana into fruit crop or cash crop commodities alongside with several other crops such as oil palm, sugarcane, pineapple, mangoes and rice. Similarly, some of these commodities do produce huge amount of cellulostic waste termed as agricultural waste or biomass.”
“Generally, banana by-products include the pseudostem, leaves, inflorescence, fruit stalk (floral stalk/rachis), rhizome and peels. Most of these by-products may serve as an undervalued commodity with a limited commercial value, application and in some cases, it is considered as an agricultural waste. The pseudostem and leaves are commonly left to rot in farms to replenish some of the nutrients in the soil,” the study stated.
The waste produced by a single banana plant can account for up to 80% of the plant’s entire mass. Annually, 220 tonnes of by-products are predicted to be produced per hectare.
“Pseudo-stem is the major portion of banana waste biomass and yields good quality fibre that has the potential for industrial applications in the making of sanitary pads, textiles, pulp and paper, food and reinforced composite materials for automobiles, construction material, aerospace and other composite materials. Recently, the Philippine Department of Science and Technology prepared masks from banana fibre which can cut the usage of single usage plastic,” confirmed a report by the University of Punjab.