By Dan Austin
For many of us, the arrival of 2023 presented an exciting opportunity to celebrate, after a lengthy period mired by COVID19, and hopefully, a chance to recharge for the year ahead. However, while clearing pandemic clouds and a new year have been cause for celebration, the horticultural world continues to face numerous challenges.
We have seen some of the worst weather extremes in our recorded history in recent years. From disastrous floods to catastrophic fires and enduring droughts, we are quickly learning to adapt to an increasingly uncertain climate. The State of the Climate Report 2022 released by CSIRO and the Bureau of Meteorology offered little to suggest these trends will change. The report includes data indicating Australia is projected to experience continued increases in air temperatures, decreasing cool season rainfall across many regions with increasing short-duration heavy-rainfall events throughout the seasons, more heat extremes and fewer cold extremes, increasing dangerous fire days with longer fire seasons and fewer tropical cyclones, but of higher intensity.
These extreme climate events pose a threat across industries but with plants so intrinsically linked with the environment, our industry is amongst the most at risk. Beyond ornamental landscapes, it is the role that horticulture plays in securing the world’s food production that is the industry’s most crucial task and perhaps most concerning. How an increasing population will be fed while arable land decreases and extreme climate events become more frequent, is a question hot on the agricultural agenda across the globe.
While the data appears gloomy, the good news is that people have been working to address these challenges for some time and we have a range of options to allow for continued and increased horticultural production into the future. Ag-tech, hydroponics, and protected cropping will all play their part, as may gene editing and genetic modification. Selective breeding has long allowed humans to increase the range in which we can grow specific crops and the ability to graft desirable crops onto versatile flood, drought and salt-tolerant rootstocks has, and will, continue to allow growers to overcome some of the emerging challenges.
However, at some point it is likely we may need to adjust our reliance on traditional crops and adapt to more climate-compatible species. The diversification of food crops isn’t a topic only useful when addressing food security in a changing climate. With only a handful of Earth’s more than 50,000 edible plant species commercially utilised, diversification of mainstream diets really is overdue.
This aspect of tackling climate change should be seen as one of the most exciting. History has proven that with the commercialisation of any underutilised ingredient comes experimentation by trained chefs and backyard enthusiasts alike. The resulting recipes are often delicious and snapped up by celebrity connoisseurs and Instagram foodies near and far. Need proof? Just look at the native produce and wild foraged ‘weeds’ that now grace the menus of high-end restaurants across the country. On trend, sow thistle (Sonchus oleraceus), wood sorrel (Oxalis corniculata), saltbush (Atriplex nummularia), and native oregano (Prostranthera rotundifolia), are just a few ingredients that would have been deemed unconsumable in years gone by.
So, what crops might best fit Australia’s changing climate? Well, several suitable crops aren’t all that unfamiliar. Many Mediterranean species grow in stifling conditions with little water and still produce great yields in their native habitats and have long been seen as appropriate for Australia. Though they do not necessarily dominate supermarket shelves, figs, pomegranates and jujubes are ideal crops for a changing climate, with opportunities in Australia to increase production.
While we are used to consuming the syconia (the part we eat which isn’t technically a fruit) of the common fig (Ficus carica var. domestica), there are numerous lesser-known edible figs throughout Asia that could be commercialised, the young leaves and buds of which have also traditionally been eaten. Pomegranates (Punica granatum) too, come in a diverse array of colours, flavours and acid profiles, with yellow, white and black varieties under-commercialised, along with the traditional red form. Jujubes (Ziziphus zizyphus) are another crop receiving attention and increasing in commercial production in Australia. With a pleasant texture, flavour and good shelf life, this fruit has remained obscure amongst much of Australia’s European population but is a favourite among many Asian cultures. An ideal species for continued commercialisation, the biggest concern with this crop is the potential weediness of the rootstock often used, which allows the trees to succeed virtually anywhere, so any suckers should be quickly removed.
Ok, there may have been a few varieties in the above plants that sounded interesting but nothing ground-breakingly different or unusual. What else might be commonplace on our plates in the future? There is a lot of research happening around halophytic (salt-loving) crops which include a range of edible cacti, succulents and semi-succulent species. Salsola soda, known as Agretti and popular in Italy, has potential as both a salad and cooked vegetable. It grows in a range of extreme conditions and has even been used to desalinate soils. Growing in similar conditions are the many varieties of samphire including Salicornia species. The stems of these plants are often pickled and served to accompany seafood, although when picked young, they are great buttered and sauteed.
Perhaps the ultimate halophytic crop you are likely to see more of in the future, is one that grows in saltwater itself – kelp. It is almost guaranteed that seaweeds such as kelp will be a significant part of future farming systems. They produce yields of high nutritional value, are fast-growing and require no land use for growing. Furthermore, these crops absorb carbon dioxide while growing which changes the pH of the surrounding seawater and reduces the consequences of ocean acidification.
Exploring these underutilised crops by no means signals that climate change will put an end to our favourite fruit and vegetable staples but what it does highlight, is that it is a great time to appreciate the fantastic produce we have in Australia and the interesting cuisine that might lie ahead.
Main photo: Developing fruit of a pomegranate (Punica granatum)