Can Tree-crop Horticulture survive the next ‘big blow’?

Australia’s tree crop industries are in a precarious position, constantly aware that the occurrence of the next Tropical Cyclone - colloquially known amongst those who have endured one as a ‘big blow’ - is inevitable. The uncertainty is not whether a Tropical Cyclone will occur; rather, it’s a question of when.

Each year, from November through to April, the threat of Tropical Cyclones looms, presenting a significant risk to the stability and resilience of Australian agriculture. This six-month period is particularly fraught for growers in Northern Australia, as cyclones have the potential to cause widespread devastation at a time when crops are typically in peak production.

The effects of Tropical Cyclones are evident and severe. A single event can be catastrophic enough to financially cripple growers. Beyond the immediate destruction, the aftermath may lead to the collapse of entire industries, the loss of export markets, disruption to food supply chains, and decreased food security across the region.

Whilst Tropical Cyclones are not a new phenomenon to growers, our understanding of the nature and intensity of these events is evolving, with the current system of detection, classification, tracking and reporting having been refined in the mid-1980s. Long-term climatic modelling indicates that whilst the frequency of events is decreasing year-on-year, the severity of each event will continue to increase with a higher probability of more extreme events occurring.

A rise in ocean temperatures means that ideal climatic conditions needed to generate and sustain Tropical Cyclones will be more prevalent. As such, an increased likelihood of impacts on tree crop orchards associated with more severe events crossing the coastline is anticipated.

In December 1974, severe Tropical Cyclone Tracy crossed the Northern Territory coast, resulting in significant destruction of buildings, crop damage and the loss of 66 lives. Within five years of this event, the Building Council of Australia would instigate the largest expansion of building standards for structures in Cyclone regions ever recorded.

While broader society has implemented a range of strategies to prepare for and manage the impacts of Tropical Cyclones, such measures have not been widely adopted within the agricultural sector. This gap in readiness is particularly concerning given the significant risks these events pose to tree crop industries and the wider agricultural community.

Research undertaken through this Nuffield Scholarship has revealed a notable lack of preparedness amongst growers. The findings highlight that most growers have not adequately addressed the evolving threat of Tropical Cyclones, leaving the sector vulnerable to the immediate and long-term consequences when events occur.

The risk to Australia’s agriculture sector, whilst severe, is significantly lower than that of other countries which are closer in proximity to the equator. In countries like Japan, Singapore and parts of India, Tropical Cyclones are an annual risk, making this a truly global challenge to the long-term sustainability of the agricultural sector.

Whilst Australia is generally underprepared for the future of a changed climate and the impacts from Tropical Cyclones, there are several current research and extension projects which are looking at ways to future-proof tree crop industries. In this space, it was found that whilst Australia is a leader in adopting systematic change, uptake of transformative practices is slow.    

Offering management and mitigation strategies to growers is challenging, especially when the risk is not immediately apparent.  Key findings from this report highlight that management measures do not require a drastic re-think of cropping methodologies or growing practices. Rather, the required change involves a transition from focusing solely on a production methodology targeting market-based characteristics only to one that creates stronger, more resilient orchards.

Other horticultural industries, particularly those in the temperate climates such as berries and medicinal cannabis, are already trialling and utilising a broad range of production methodologies which have the potential to be adjusted and utilised for tree cropping. Globally, the use of growing hothouses and greenhouses, particularly in the vegetable space, has allowed growers to overcome climatic conditions and achieve enhanced production outcomes.    

Notable management and mitigation measures were found to primarily sit within the remit of growers; however, support and collaboration with government will create a more streamlined and timely transition to resilient orchards. High-density plantings coupled with supporting systems such as trellising were identified as the most obvious and easily implemented solution for in-field plantings, however, the understanding and practicality of this approach for tree cropping in Tropical Cyclone regions is yet to be fully understood.

Increasing the quality of planting material provided by commercial nurseries will also play a long-term key role in developing resilient orchards. The current focus of developing planting material which maximises a focus on production must be reduced in favour of a balance with stronger trees that exhibit improved climate resistance traits.

Adoption of these production methodologies typically includes an increase in production yields and a reduction in inputs on a per hectare (ha) basis. This outcome is required to cover the up-front capital investment necessary to adopt this transition. Growers must be prepared to focus on developing orchard resilience through growing strong trees over market-focused qualities in isolation for this approach to be truly effective.

The adaption and adoption of alternative growing methods through hothouses and greenhouses provides a potential opportunity to decouple production from the peak Tropical Cyclone timeframes. Whilst this methodology will require further research and extension prior to adoption, it provides a mechanism for growers to utilise technological advancements and crop science to stagger production across a broader portion of the year. This approach will also allow for a more desirable cash flow.     

The tree crop industry faces a new challenge and one it must be prepared to overcome if it is to prosper into the next decades. Resilience, which is largely applied to a business thinking process must be the focus of the design, implementation and management of orchards to ensure sustainable production into the future.