Citrus postharvest program (CT19003)

What was it all about?

This program delivered industry-focussed R&D to keep the Australian citrus industry informed on postharvest best practice.

Building on outcomes delivered by previously levy-funded project Australian Citrus Postharvest Science Program (CT15010), this project delivered new information and innovative technologies to improve the quality of Australian citrus and ensure that growers gain access to effective new methods.

Challenge

The Australian citrus industry is in a period of growth, but grower profitability will require further growth of current markets and development of new markets. Australia demands a premium for its citrus fruit due to its excellent quality and high eating quality attributes. It is critical to maintain and build upon this high-quality status with practical and cost-effective technologies to improve fruit quality through to the consumer.

Postharvest is the key link between the orchard and the consumer and can either enhance or detract from the investment into quality fruit pre-harvest. However, maintaining fruit quality is particularly challenging with the long storage times (due to disrupted shipping) and the application of phytosanitary end-point treatments required for many export markets. In addition, growing consumer (and market) expectations of lower chemical residues put further demands on consistently delivering high quality fruit to consumers

Response

Postharvest storage trials were conducted to assess the efficacy and practicalities of alternative postharvest decay control which is the major issue for the marketing of citrus. These research trials examined commercial and experimental alternatives to current postharvest fungicides to control postharvest decay (green and blue mould). A new formulation of OPP (Ortocil®) showed promise in research trials and was subsequently registered with the APMVA by the chemical company for use in the industry. The commercial application of new chemistries / technologies is a great result for industry to diversity its decay management tools to meet different market needs. Postharvest storage trials were also conducted to improve the management of anthracnose in Imperial mandarins.

In addition, fruit storage trials to improve market access outcomes were undertaken. These included a long-term survey of chilling injury from different Navel cultivars grown on the same location and rootstock.

The interaction of pre-harvest orchard management and postharvest storage life over extended storage periods was also examined and showed orchard management techniques such as the application of plant growth regulators and restricted irrigation management had some benefits to final fruit quality.

The assessment of alternatives to postharvest waxes were also assessed on the storage and shelf life of lemons and showed some promise to meet different market expectations.

These research results underpin the citrus industry’s science-based approach to consistently delivering high quality.

Benefit

The continued success of the Australian citrus industry relies on the delivery and adoption of relevant and timely information. The Program delivered up-to-date postharvest resources (e.g. regular articles in ‘Australian Citrus News’) and Program updates at grower forums and workshops (e.g. Citrus Australia Regional Forums and Citrus Congress) that are essential to ensure industry are using best practice and meet retailers/consumers expectations.