Food, clothes, medicines, shelter – the very oxygen we breathe –all from plants!

By Marisa Romano

As 2020 made its entrance, plant pathologists all over the world had an added reason to raise their glasses: the United Nations General Assembly has declared 2020 International Year of Plant Health.

The foreseeable outcome is an increase in resources to support plant health worldwide and ultimately raise awareness of the contribution of plant pathologists to our everyday lives. Would that also add “plant doctors” to the list of potential occupations for the new generations of students?

“Plants are essential to all life on Earth, including humanity,” underlined António Guterres, Secretary-General of the United Nations, in his proclamation message. “They provide us with most of our food and the oxygen we breathe…and we all rely on them for clothes, medicines and shelter among other things.” The commitment to plant health is undoubtedly an essential step towards the Sustainable Development Goals adopted by all UN Member States: “end poverty, protect the planet and ensure that all people enjoy peace and prosperity by 2030.”

PLANT DISEASES

Like all other organisms, plants are susceptible to diseases. Fungi, bacteria, virus and pests can cause severe damage to vegetation. We witness it in the decaying of houseplants and the dwindling of flowers in our gardens. When dealing with what we eat, we notice the sudden spike in the price of produce – which is at times a sign of disease outbreaks in areas of production – and we see the decaying of produce stored in our fridge for too long. With regard to the loss of food by plant diseases and pests, this is only the tip of the iceberg.

A recent global survey reported annual yield losses between 20 and 30 per cent in wheat, rice, maize, soybean and potato, the staple crops that provide half of global caloric intake. Impoverished regions with fast-growing and food-insecure populations and with less effective crop disease management are the most affected. Alarming enough, these significant food losses occur at a time when there is the need to increase food production to feed an expanding global population.

The work of plant pathologists is essential to develop phytosanitary measures necessary to maintain plant health, limit yield loss and increase food production. This job is increasingly challenged by the climate crisis, the loss of crop resilience due to agricultural intensification, and the spread of invasive pests and diseases, which is caused by the frequent movement of people and goods around the globe. The UN recognizes these challenges and encourages action towards plant health.

FOOD SPOILAGE

The work of plant pathologists also includes the prevention of food spoilage after harvest. Damage to food occurs in the field, but also beyond the farm gate. The UN’s Food and Agricultural Organization has estimated that globally we are losing or wasting about one-third of food production after harvest every year. Plant pathogens are a major contributor.

How can we keep our fruits and veggies fresher longer and avoid spoilage? Fruits and vegetables are at their best at harvest – mmmm those strawberries sampled at the pick-your-own farm! Produce quality starts deteriorating after that and post-harvest diseases can cause rot, making food unpalatable and toxic, good only for the composter. Remember, if the damaged spot is small enough you can remove it, but also cut out a good chunk of healthy flesh around it!

Bruised, cracked fruits or damaged produce spoil quickly. The open peel allows fungal spores and bacteria to enter into the flesh and grow, so eat the damaged apple first. How fast the mould grows depends on how we store the produce. Warm temperature and high humidity are bad news. Keep fruit in a cool place, spin the washed salad before storing it in the fridge and cut holes in those big bags of carrots to allow for air circulation. Once moulds grow on the surface they move quickly from fruit to fruit. They produce a massive amount of spores ready to grow on healthy fruits. Remove the fuzzy berries as soon as you see them. Toss the greening lemons and wash the healthy ones left in the package. Remember that citrus fruits are coated with a wax that keeps them from drying out. In conventional practice, the wax is mixed with fungicides that suppress the growth of post-harvest rot so opt for organic fruits when you use the zest for your cakes!

For a comprehensive list of best practices to help keep your produce fresh longer check the Home Storage Guide published by the Canadian Produce Marketing Association available at www.halfyourplate.ca.

Marisa Romano is a plant pathologist who worked as a researcher at the University in Turin, Italy, and in Guelph, and has done regulatory work in Health Canada’s Pest Management Regulatory Agency.