What is it all about?

This project is building knowledge and resources to support a transition to growing systems with improved resource efficiency (space, water and labour) for producing high-value citrus crops.

Challenge

Rising production costs (electricity, water and labour) are eroding returns and decreasing international competitiveness for Australian citrus growers. In addition, competitive global markets are demanding higher quality fruit for Australians to achieve premium prices. It may be possible for growers to keep pace with these increasing demands with a change in production system. A successful ‘narrow-canopy’, or 2D-plane fruit production system (i.e., trellis), may enable robotic picking and, in the short term, increased efficiency of traditional harvesting methods (platform harvesting).

Response

The research team will:

• Quantify how different canopy management strategies impact crop load over time within existing high-density orchards with the aim to maximise profitability.
• Quantify the performance of different mandarin and orange varieties grafted to different rootstocks with different training systems (espalier and cordon) to build knowledge about the transition to a new 2D production system. 
• Quantify the canopy growth and productivity of two young viroid dwarfing experiments and describe the implications that will have for growers.
• Quantify the effect of limb selection, bending and training on young trees. 
• Report on the current use of Plant Growth Regulators (PGR) for the control of canopy expansion/growth rate in citrus, both in the literature and from experts around the world and demonstrate the most promising ones to growers. Following a stop/go decision, we will demonstrate the efficacy of products claiming to slow canopy growth as a tool to manage vigour in citrus orchards.
• Collect a detailed, annotated dataset from our new trellis experiment that will be able to be used in future machine learning modelling work. 
• Collect spatial datasets of tree geometry and fruit attributes with a mobile platform (LiDAR, RGB camera and RTK) of the Dareton PII research plantings and at growers’ properties to describe tree growth and development in advanced citrus orchard systems.
• Deliver a communication and extension program, including case studies, fact sheets, videos, presentations and field days, to empower growers to use the project’s findings to make informed business decisions.

Benefit

The project will deliver positive, practical outcomes for industry in addition to contributions to academic knowledge. Following exposure to project outputs, it is expected that citrus growers will have more confidence when making decisions about new, high density planting systems and whether to change their working practices and adopt different technologies on farm. This project will develop new information for growers to make business decisions about new production systems, based a thorough understanding of these systems, supported with data on their financial performance.