Protected Cropping
Cherry production is expanding quickly into new geographic regions in NSW due to recent growth in demand from overseas markets for high quality cherries. Each year, cherry production is challenged by adverse weather conditions that impact both yield and quality. Rain events around harvest can induce cherry cracking which will downgrade a cherry to unsaleable. Retractable rain covers to shield fruit from rain can be highly effective at minimising the impact of rain events but are expensive and labour intensive to deploy each season. Some automated systems can reduce the labour needs but come at a premium price point for growers. The use of these protective rain covers in cherry orchards has not been widely adopted in NSW for reasons including cost of installation, perceived impact on quality and the extra time needed to manage the covers.
Protective rain covers have the potential to increase yield and quality through reduced cracking and splitting. Other benefits have included more control over irrigation and spray management, and reduced wind damage.
Climate for cherry production
Sweet cherries are sensitive to climatic variables during the growing season including frost, wind, rain and heat. Climate change might reduce the dormancy period, where temperatures are cool enough to accumulate winter chill portions, which might delay or advance bud burst and flowering. Temperatures exceeding 30oC can also negatively impact fruit size and firmness. During the growing season extreme events such as frost, excessive wind, and heat waves can reduce yield and quality.
Across Australia, agricultural growing regions can expect changes to climatic conditions. Overall, Australians can expect numerous changes to climate (Figure 1).
The main cherry growing regions in NSW are Young, Orange, Hillston, Bilpin Mudgee, Tumut and Batlow. Future climate projections suggest that these regions could see an increase in overnight and daytime temperatures, more variable rainfall, and an increase in drought conditions (AdaptNSW, 2022).
Cherries in Orange, NSW
Orange is located on the central tablelands of NSW with a temperate climate with cool winters and mild summers. Orange is one of the sunniest cool climate regions in Australia, with 9 hours of sunlight during the growing season (Orange Region Vignerons Association (ORVA), 2010)
The mean January temperatures in Orange range from 19 - 21.5◦ with a difference of 15◦C between summer and winter. The maximum daytime temperatures in summer can be greater than 30◦C while the minimum temperatures in winter can exceed -8◦C. The annual average rainfall in the region around Orange ranges from 700-950mm, making this region part of the high rainfall zone. The relative humidity in Orange ranges from 60-70% at 9 am in January and can be up to 90% in June (Bureau of Meteorology (BOM), 2022).
The Orange region is ideal for cherry production due to its temperate environment. However, the high spring rainfall can lead to an increase in cherry splitting.
Climate Variable | October | November | December |
Average minimum temperature | 6.7oC | 9.2oC | 11.3oC |
Average maximum temperature | 18.0oC | 21.3oC | 24.6oC |
Average rainfall | 79.2 mm | 81.7 mm | 79.0 mm |
Current projections have predicted that the Orange region will experience some changes to climate that growers will need to be aware of. These include
- Increase in average temperature
- Increase in variability and intensity of rainfall
- Longer durations of drought
- Reduced ability to accumulate chill hours
Knowledge of the future climate projects for Australia, and specifically Orange, it is important we look at adaptations for the NSW Cherry Industry to remain resilient and consistent producers of good quality produce.
Case study farm
To determine if using protective rain covers in cherry orchards in NSW are an effective way to adapt to climate, NSW DPIRD’s Climate Smart Pilots Program ran a limited 2-month trial of rain covers over summer in 2022-23. Using a suite of digital technology, they monitored the impact of using covers in an existing cherry orchard growing 2 varieties (Lapins and Sweet Georgia) at Nashdale (near Orange NSW).
As the climate becomes more unpredictable and extreme weather events become more common, protective rain covers appear to be a strong option for growers to protect their crop against these climatic factors. Researchers from NSW DPIRD are working with growers to test new technologies to make their orchards more resilient to a changing climate. Sensors were deployed in the orchard capturing real-time weather conditions under covers and in control blocks (see Table 2).
| Sensor | Use | Type Used |
|---|---|---|
| Anemometer | Measure wind speed and wind direction | Davis Ventage Pro |
Temperature and humidity sensor | Measure changes in temperature and humidity | Netvox R718A |
| Soil moisture probe | Measure changed soil moisture and soil temperature at one depth | Meter Teros-12 |
| Weather station | Measures 12 weather variables including: air temperature, relative humidity, vapour pressure, barometric pressure, wind speed and direction, solar radiation, precipitation, lightning | Meter Atmos-41 |
| Central communicator | Connects sensors to a common panel and sends data to be received by the grower to read | LoRaWan Gateway (MultiTech Conduit IP67) |
Being able to make an informed decision, based on data and local research will increase the adoption of protective covers in the NSW cherry industry. Further work into the economic viability to combine with the results of our trial will make this more effective. We hope to continue this trial, with the addition of new locations and types of net to create more datasets for industry to use to make more decisions.
If you would like to be involved in this trial, or you are interested in learning more, please contact Jessica Fearnley, Development Officer Temperate Fruits on 0437 284 010 or jessica.fearnley@dpi.nsw.gov.au
References
Orange Region Vignerons Association (ORVA). (2010). Orange region terrior: A review of the unique features of the Orange wine region NSW - Australia. Retrieved from https://www.orange360.com.au/Wineries/Terrior
AdaptNSW - https://www.climatechange.environment.nsw.gov.au/home