This update provides information from ‘ST19013 Multiscale monitoring tools for managing Australian tree crops – Phase II’ managed in part by the Department of Agriculture and Fisheries, Queensland. This forms part of the overarching program ST19000 which is continuing the development, trial and extension of technology-based crop mapping and monitoring tools to help growers in predicting fruit quality and yield and monitoring tree health – including the early detection of pest and disease outbreaks.
The Australian Mango Crop Forecasting program has been underway for six seasons. The aim of yield estimation and crop forecasting is to provide seasonal data on fruit volumes and quality entering the supply chain, so that growers, wholesalers and retailers have some lead-time to take action for managing under- and over-supplies of fruit entering the marketplace.
An accurate forecasting system can help growers by minimising large price drops through unexpected periods of market oversupply and help wholesalers and retailers by enabling greater time to prepare marketing and sales activities.
The Review
A recent review of industry yield estimation and crop forecasting systems has been positive. This review was conducted as part of a Hort Innovation-led Rural R&D for Profit research project (See Acknowledgements section for details).
Key findings from the program, including analysis of the 2019/2020 season were:
The forecasting program is capturing approximately 85% of actual national mango volumes.
Forecast volumes provided 1-2 weeks before harvest by growers are on average 10% higher than actual dispatch volumes.
Earlier forecast volumes and harvest dates (e.g. collected at flowering, fruit set or 4-6 weeks from harvest) were less accurate but provided highly valuable insight of seasonal flows.
The current system is a relatively simple, manual process which relies heavily on the efforts and effective relations between Industry Development Officers (IDOs) and growers.
Australian Mangoes Crop Forecasting Process
IDOs send an excel spreadsheet to individual growers at fruit set. Forecasting information is then entered by growers including estimated tray volumes (7kg) by variety and class for each week of their harvest. Key timings for the forecast program are at fruit set and at 1-2 weeks prior to harvest. Additional updates may also be made during fruit development at 4-8 weeks prior to harvest. All forecasting information is collected by the IDOs and updated into the Australian Mangoes weekly crop flow report. Each week during a grower’s forecast harvest period, an automatic text is sent to growers requesting actual dispatch data, which is then incorporated into the crop flow report each week.
Figure 1: Comparison of mango forecast volumes compiled 1-2 weeks prior to harvest vs weekly grower dispatch data (2019/2020 season).
Figure 2: An excerpt of a weekly crop flow report (dated 19.01.2021).
Grower forecasting methods (BMP survey results)
The 2020 Best Management Practices Survey found that Aussie mango growers had lower confidence in their methods for estimating yields and forecasting fruit volumes, compared with their other growing practices. The methods used by growers to estimate volume of production involved transect fruit counts with orchard variability accounted for (50%), informal observations and random counts (39%), and gut feel and past experience (11%). The majority of growers (89%) used multiple methods to predict harvest dates and the decision to pick including; flowering date, heat sum units, internal fruit colour, fruit shape and NIR dry matter percentage.
Figure 3: Manual fruit counts for paddock yield estimation on Calypso trees at Dimbulah.
Where to from here?
The mango crop forecasting system is still relatively young compared with other forecasting programs in industries such as avocado and citrus. There are opportunities to address barriers, increase participation, streamline processes and improve value to all stakeholders in the supply chain.
Three key aspects that should be addressed:
Provide better information to clearly demonstrate the value proposition of crop forecasting to growers and the wider industry. This includes having data flow both ways, perhaps through weekly updates by wholesalers and retailers of marketplace trends, how much is being stored in cold rooms and better information on how volumes are impacting on price.
Explore specific regional issues around forecast accuracy, supply overlaps between regions, and the practicalities of achieving more accurate, earlier volume estimations (e.g. 4-6 weeks prior to harvest) rather than one week prior to dispatch.
Develop more standardised, accurate, yield estimation tools and data collection protocols with growers, IDOs and pack-house managers to improve efficiency, streamline data collection and reporting. This includes improvement of existing manual yield estimation methods, development of new multi-scale yield and maturity monitoring technologies, and improved digital record keeping in pack-houses to enable easier supply of forecast data.
Acknowledgments
This review was conducted as an activity within the project ‘Multiscale monitoring tools for managing Australian tree crops – Phase II”. The project is being delivered by Hort Innovation – with support from the Australian Government Department of Agriculture as part of its Rural R&D for Profit Program and Central Queensland University, University of New England, Australian Mango Industry Association, Queensland Department of Agriculture and Fisheries (DAF), NSW Department of Primary Industries and the Northern Territory Department of Industry, Tourism and Trade.
Article provided by Sue Heisswolf, Geoff Dickinson, and Dale Bennett, DAF, Bowen and Mareeba. For more information contact susanne.heisswolf@daf.qld.gov.au or geoff.dickinson@daf.qld.gov.au