My research aims to help farmers in the tropics whilst discovering how plants, pests and microbes interact. Brambles, biological control organisms, bananas and now, sweet potatoes.
I joined SCI after receiving the David Miller Travel Bursary to attend the International Banana Congress in Miami in 2019. Now, I am the new Secretary of the Horticulture committee and I am part of the Agri-Food Early Careers Committee.
I started my undergraduate studies in Marine Biology as a bit of rebellion against my plant pathologist father. After living with Nepalese farmers in 2017, I switched universities to study Plant Biology. Last year, I started an PhD to work with a banana disease in Costa Rica, but I decided to exit the Doctoral Training Program with an MRes due to concerns about the lab environment. Next week, I will (re)start my PhD at the University of Southampton which will involve working with subsistence farmers in Papua New Guinea.
It sounds like my life is a bit of a roller-coaster. It is. I love it.
In 2017, another scholarship took Juniper to Nepal to visit plant clinics and live with farmers.
Whilst I received “Top Student” awards for graduating with a high average – I never really studied from textbooks. I worked as a technician in labs and attended as many conferences as I could with scholarships. Often, I was the only undergraduate at international conferences or symposiums but that is where I learnt the behind-the-scenes stories of how scientists question how the world works.
Moments of random kindness, spare-of-the-moment dancing at conferences, and ridiculous situations I put myself in are the highlights of my scientific career – so far.
PhD Tips and Reflections
Personally, the workload of a PhD is not that scary, and I find it exciting to lead my own project. The biggest challenge of my PhD last year was to put my foot down and say that I did not feel comfortable around some colleagues. My pre-PhD advice would be to choose people over projects, be honest with yourself why you would like to do a PhD to begin with, and what skills you need to gain for post-PhD jobs.
“The workload of a PhD isn’t that scary”
The COVID-19 pandemic put a halt on my rotation project at the Eden Project (Cornwall) in March and it is hard to predict when I will be able to travel to Papua New Guinea. I have been attending online events, panel discussions and conferences every week spring lockdown which have been a fantastic way to keep feeling engaged with the scientific community.
Whilst starting a PhD in a pandemic is strange – I am very excited about my project. I will be exploring options for working with local technicians remotely. I am planning on studying nutritional and social aspects of food security which has been inspired by an interview with an ethnobotanist and virtual conferences.
If there is one opportunity in this pandemic, it is to reflect on our behaviour, choices, and responsibility to live in harmony with nature and bring each other along.Juniper Kiss is a NERC INSPIRE DTP student at the University of Southampton, and a member of SCI’s Agri-Food Early Career Committee and SCI’s Horticulture Group
The banana colour scheme distinguishes seven stages from ‘All green’ to ‘All yellow with brown flecks’. The green, unripe banana peel contains leucocyanidin, a flavonoid that induces cell proliferation, accelerating the healing of skin wounds. But once it is yellowish and ready to eat, the chlorophyll breaks down, leaving the recognisable yellow colour of carotenoids.
Unripe (green) and ready-to-eat (yellow) bananas.
The fruits are cut from the plant whilst green and on average, 10-30 % of the bananas do not meet quality standards at harvest. Then they are packaged and kept in cold temperatures to reduce enzymatic processes, such as respiration and ethylene production.
However, below 14°C bananas experience ‘chilling injury’ which changes fruit ripening physiology and can lead to the brown speckles on the skin. Above 24°C, bananas also stop developing fully yellow colour as they retain high levels of chlorophyll.
Once the green bananas arrive at the ripening facility, the fruits are kept in ripening rooms where the temperature and humidity are kept constant while the amount of oxygen, carbon dioxide and ethene are controlled.
The gas itself triggers the ripening process, leads to cell walls breakdown and the conversion of starches to sugars. Certain fruits around bananas can ripen quicker because of their ethene production.
By day five, bananas should be in stage 2½ (’Green with trace of yellow’ to ‘More green than yellow’) according to the colour scale and are shipped to the shops. From stage 5 (’All yellow with green tip’), the fruits are ready to be eaten and have a three-day shelf-life.
A fruit market. Image: Gidon Pico
The very short shelf-life of the fruit makes it a very wasteful system. By day five, the sugar content and pH value are ideal for yeasts and moulds. Bananas not only start turning brown and mouldy, but they also go through a 1.5-4 mm ‘weight loss’ as the water is lost from the peel.
While scientists have been trying out different chemical and natural lipid ‘dips’ for bananas to extend their shelf-life, such methods remain one of the greatest challenges to the industry.
In fruit salads, to stop the banana slices go brown, the cut fruits are sprayed with a mixture of citric acid and amino acid to keep them yellow and firm without affecting the taste.
Bananas are a good source of potassium and vitamins.
The high starch concentration – over 70% of dry weight – banana processing into flour and starch is now also getting the attention of the industry. There are a great many pharmaceutical properties of bananas as well, such as high dopamine levels in the peel and high amounts of beta-carotene, a precursor of vitamin A.
Whilst the ‘seven shades of yellow’ underpin the marketability of bananas, these plants are also now threatened by the fungal Panama disease. This vascular wilt disease led to the collapse of the banana industry in the 1950’s which was overcome by a new variety of bananas.
However, the uncontrollable disease has evolved to infect Cavendish bananas and has been rapidly spreading from Australia, China to India, the Middle East and Africa.
The future of the banana industry relies on strict quarantine procedures to limit further spread of the disease to Latin America, integrated crop management and continuous development of banana ‘dips’ for extending shelf-life.