Extension of citrus practices to maximise marketable fruit size and economic returns through on-farm trials (CT10030)

What was it all about?

During the past decade, many new products and production practices have been promoted within the citrus industry, however little was really known about how successful these practices have been in farms and orchards located across a range of Australian conditions.

The key aim of this project was to identify non-profitable practices, while extending the uptake of practices that increase yield and marketable fruit. A secondary aim of the project was to investigate and develop ways to evaluate new technologies through on-farm trials.

From 2010 to 2013 the project conducted 22 replicated citrus (mainly navel orange) demonstration trials on-farm in the Sunraysia region that examined a range of products and practices. The results of these trials were extended to industry through annual field days, seminars and conference presentations.

Products and practices trialled included…

• Potassium (ground and foliar applied)
• 2,4-D fruit sizing spray (Corasil)
• Winter gibberellic acid (GA, Ralex)
• Hand thinning
• Hand pruning
• Summer urea fruit sizing spray
• GA flower fruit setting spray
• Young tree growth biostimulant enhancing sprays
• Kaolin clay foliar sprays
• Wind blemish assessment.

Trials on potassium nutrition indicated that cost savings and improved rind quality can occur if foliar potassium sprays were only used when fruit size was below the acceptable size range or in high demand situations.

A cost benefit analysis model was developed to assess the financial benefit or loss of practices. The model used typical fruit box prices for quality and size grade. The cost benefit analysis identified the potential benefit of cheap fruit size and yield enhancement practices, such as winter GA, flower GA, 2,4-D and summer urea. 2,4-D (Corasil) trials demonstrated increased fruit size and grower returns.