Harvest practices for avocado

Proper picking of avocado is a precondition to being successful in the rest of the supply chain. The performance of the pickers is therefore critical to deliver a good quality product. First of all, picking at the right maturity is important to develop a satisfactory taste. Picking and further handling must be done carefully to avoid bruising and other damages to the product. The use of clean and suitable materials such as harvest crates also serves this purpose.

Harvesting of avocados. Photo by anarociogf/Shutterstock.com

Harvest of avocados

Avocados are climacteric fruits. This means that, once mature, they will ripen further after harvest. Avocados are often harvested when they are still green and firm, so they can reach distant markets. On the other hand, they must be sufficiently developed to be able to ripen and reach optimum quality later in the supply chain. Determining the right harvest moment is therefore important for the eating quality and marketability of the avocados. Good training, instruction and monitoring of individual pickers can ensure a good starting quality.

Attention points when harvesting avocados

  1. Varying age of avocados hanging on one tree. Photo by WFBR.

    Harvest maturity

    Avocado fruit dry matter is highly correlated to fruit oil content and is currently the key maturity index used. Higher concentrations are indicating more mature avocados. Protocols describe a certain minimum and maximum content.  Also skin colour is used as an indicator for some cultivars which turn from green to black or purple. The harvest stage for avocados often depends on the destination market and prices. Even for experienced and trained pickers it is still difficult to assess which fruits to pick on the tree.
  2. Overview avocado orchard in Peru. Photo by WFBR.

    Harvest frequency

    The flowering period of avocados spreads over a long period resulting in many avocados with varying maturity on a tree. Therefore it is recommended to not harvest all in one time, but repeat it during the season. Avocados are preferably harvested in the coolest part of the day (in the morning). In this way, the cooler fruit temperatures will facilitate fast cooling to the optimum temperature in the packhouse. Avoid the harvest of fruit after rain, as surface moisture can enhance disease development. Also stopping irrigation a few days before harvest may prevent damage to lenticels in the skin
  3. Harvest of avocado with a harvest net. Photo by anarociogf/Shutterstock.com

    Harvest method

    The fruits must be cut from the tree, leaving 0.5 to 1.0 cm of the peduncle. Pulling may cause the peduncle to be completely removed, which increases the fruit respiration and the susceptibility to pathogens. Harvesting the fruit must be done carefully without damaging the fruits. In high trees, this is more difficult than in lower trees. Nets with a sharp blade attached to it are to be used for fruit hanging in places that cannot be reached easily. In lower trees, clippers are preferred
  4. Careful placing avocados in bins. Photo by Jorge 1984 Valencia/Shutterstock.com

    Placing in crates or bins

    Place the avocados carefully in crates/bins, for instance by using dropbags. There should be no or only limited dropping distance. Best practice is to lower hands with fruits into the crate. Crates should not be overfilled: when stacking, the crates should not touch the fruit in the crate beneath. Leaving some space between crates room for ventilation, which prevents heating up. The field crates must not be exposed to direct sunlight until transported to the packhouse. This can realized best by means of cloth and shade, rather than using leaves or other organic matter.
  5. Quality check and removal of diseased or damaged fruit in the orchard. Photo by WFBR.

    Diseased and damaged fruit

    Diseased or damaged or fruit should not end up in the crates intended for high-end market segments. Avocados that are suitable for export are at least firm, free from decay and free from damage such as cracks, bruising and insect or sunburn damage. A preliminary grading could be conducted in the field by placing under-/oversized, under-/overripe and damaged fruit in separate crates
  6. Desinfection of used materials. Photo  by WFBR.

    Materials

    The availability of good, clean and sufficient materials will facilitate harvest and product quality will benefit. Field crates should be stackable and intact without sharp edges. Tools for high trees are ladders and/or picking poles with clean net (or bag) and sharp knife blade. Clippers should also have sharp blades
"It is important that avocado harvesting teams/ farmers receive training in harvesting procedures and fruit maturity determination."
René Oostewechel - Consultant Postharvest Technology (WFBR)