Harvesting avocados

Grafted avocado trees may start to bear fruit in the second year, but you generally won't harvest commercial quantities until the third year.

Expected yields

Growers using good rootstocks and good management of root rot, irrigation and nutrition can achieve average yields of over 20t/ha. Once trees form a hedgerow, a biennial bearing pattern with an 'on-year' and 'off-year' can develop especially if trees are harvested late.

The average yield across all Australian orchards is a low 9t/ha.

Low yields are often the result of poor:

• management of phytophthora root rot disease
• management of soil moisture
• variable rootstocks
• nutrition management.

Achievable yields

When to harvest

If you think your fruit might be ready, check it with both a ripening test and a dry matter test. Fruit should pass both tests before you start picking.

Ripening test

Pick 5–10 representative fruit and allow them to ripen at room temperature.

Mature fruit will:

• ripen within 7–12 days without shrivelling
• have good flavour
• not be watery.

Dry matter test

Weigh a sample of flesh before and after drying. You can dry the fruit in an oven or microwave. The industry recommends that Hass fruit should have reached at least 23% dry matter and Shepard fruit should be at least 21% dry matter before harvesting.

How to harvest

Avoid picking fruit when wet or fully turgid as this increases the risk of postharvest rots, sensitivity to mechanical abrasion and lenticel damage.

The Hass variety can be 'snap' picked (plucked from the tree) but should be 'snip' picked (cut from the tree with a pair of special secateurs) if there has been recent wet weather or if it's the start of the harvest season.

Varieties other than Hass should also be 'snip' picked.

Watch the Avocado harvesting: The picker's guide video for a practical guide on how to pick Hass and Shepard avocados.

Apply post-harvest fungicides

Registered postharvest fungicides should be applied to fruit within a few hours of harvest. Follow the label instructions for exposure time for effective coverage and timing after harvest.

Keep fruit cool

Avoid picking fruit during hot weather. This will shorten the shelf life of the fruit unless the field heat can be removed within a few hours of harvest using forced air-cooling.

Keep harvested fruit cool and shaded:

• cover bins with a cover or green branches
• place bins in the shade.

Handle carefully

Handle fruit carefully and minimise all fruit drops to avoid skin damage, bruising and rot development:

• lower picking bags into bins before gently releasing fruit
• minimise walking time for pickers to reach a bin
• take care during transportation of bins to the packhouse.

Grading and packing

If the fruit is brushed and cleaned, use soft brushes and manage line speed and volume load to minimise fruit damage.

Grading and packing lines should be short and padded to prevent fruit damage, and also cleaned regularly. Avocados are usually graded as Premium, Class 1 and Class 2. Grading should be conducted by trained staff who are aware of the specifications required for each class, as well as those that are rejected.

Single-layer trays or cartons are used to pack avocados depending on grade and destined market. It is important that the packaging used provides sufficient ventilation for air movement to help keep the fruit cool.

Temperature ranges

Always aim to pack and cool fruit within 24 hours of harvest, especially if the fruit is destined for export or expected to remain in the supply chains for more than 2 weeks.

Avocados need to be cooled as soon as practically possible after picking and after packing to maintain quality.

The temperature for cooling hard, green mature fruit depends on the variety:

• 4°C to 5°C for Hass with a maximum storage time of 4 weeks
• 6°C to 8°C for other varieties with a maximum storage time of 2 weeks.

Use forced air-cooling if warm fruit needs to be cooled before packing. This is a more effective way of removing heat from fruit than room cooling (up to 10 times faster) as well as preventing condensation developing.

Avocados should be thoroughly cooled and target temperatures maintained throughout the entire cool chain to preserve fruit quality.

Cool fruit before transportation, and do not rely on refrigerated trucks for this as these trucks can at best only maintain the existing temperature.