Gap analysis and economic assessment for protected cropping vegetables in tropical Australia

Abstract

The project VG16024 aims to increase awareness and information about protected cropping opportunities and technology options for the vegetable industry in the tropics through the identification of gaps in information and potential economic viabilities. Protected cropping of vegetables in Australia (estimated at 1,341 ha) is by large located in temperate climate regions and in proximity to urban areas. In warm climate regions, near and north of the Tropic of Capricorn, the segment of the industry dedicated to producing vegetables using protected cropping technologies is scattered and relatively small (estimated at <80 ha). Vegetable growers in these regions would benefit from technologies that can mitigate risks linked to climate variability and that can help them address current and future market challenges and opportunities. Evidence from overseas, including in tropical regions, and demonstration plots and farmer experiences in the Australian tropics indicate that protective cropping technologies can cost-effectively mitigate the effects of extremes in air temperatures, rainfall, low and high relative humidity, wind, solar radiation, and pests and diseases, all which currently negatively affect yield, quality and consistency of supply.
In this report, four regions, two within the tropics (Burdekin dry tropics and Atherton Tablelands) and two located a short distance south of the Tropic of Capricorn (Bundaberg and Carnarvon), are selected as examples of regions where the protected cropping industry is either small or emerging, and has the potential to expand. Vegetable production in these regions is predominantly undertaken outdoors. The establishment of protected cropping enterprises would contribute to an increase in regional production that could service both domestic and export markets. This would be facilitated by the regions’ proximity to road infrastructure, ports and airports but access to some of these market opportunities still need to be developed.
In the tropics the availability of medium level, cost-effective protected cropping structures that are effective in removing heat from crops is paramount. In this report, four greenhouse structure designs (high tunnels, passively ventilated greenhouses, retractable roof structures, and net houses) are discussed, and advantages and drawbacks compared. Capsicum, cucumbers, melons, and eggplants are given as examples of vegetable crops suited to warm climates and which can benefit from a protected environment and specific agronomy practices. Possible marketable yields are provided for these crops as well as estimates of production value for a range of size of areas that could potentially establish protected cropping systems.
A preliminary economic analysis was carried out for hypothetical production of capsicum crops in different protected cropping scenarios in the tropics. Under the protective structures, management practices, market prices and capsicum yields used in the analysis, preliminary results suggest that protected cropping could be a viable business opportunity for growers in the tropics. Future research investigating the heterogeneity of protected cropping enterprises would serve to further confirm these findings, especially in light of the practical implications of the technology used in a larger number of commercial sites.