When ready for harvesting the skin of the fruit is a deep purple colour. Its pulpy interior is bright yellow, filled with small black seeds.

FRUIT COLOUR

Low fruit colour is sometimes a problem with New Zealand passionfruit. Although this problem has not been investigated in New Zealand, comments from overseas suggest that it could be a result of environmental influences - with temperature, light, and nutrients all involved to some extent. In its native habitat the passionfruit enjoys an evenness of temperature, without much variation between day and night, so once again the somewhat variable temperatures experienced here may be a reason for low colour. Where fruit are produced under a dense canopy of foliage there is also a tendency for the fruit to be lower in colour.

YIELDS

Passionfruit come into production quickly compared to other fruit crops and should produce a half crop in the second season after planting, and be in full production in the third season.

Yields will often tail off a little from about the fourth or fifth season as some vines decline in health and vigour.

Record yields of over 20 tonnes per hectare have been recorded, but a reasonable average yield profile is shown in table 3.

The cropping season normally starts in February and continues until winter or even spring in younger plantations. The main flush comes in March and April as demonstrated in table 4.

Annual crop estimation is difficult, owing to seasonal fluctuations and the fact that fruit mature relatively quickly in a series of flushes. However, it is important for growers to anticipate their main flush and to advise their marketing agent or exporter. This will assist market planning.

If the season is late there may be no fruit harvested in February.

Frosts may reduce the crop from June onward, and pruning usually terminates the season in spring.

For well managed blocks it is possible that 40% of the crop will be exported, 40% sold on the local market, and 20% processed. The proportions of this breakdown depend on the amount of good quality fruit produced and the market opportunities in any one year.

HARVESTING

Passionfruit fall from the vine when mature, and the fruit is harvested off the ground. It is usual practice to gently shake the vines at each harvest and pick up all fallen fruit for sorting in the packing shed.

When looking for high quality fruit it is possible to pick some from the vine, but this must be fully coloured and close to its natural drop. Fruit picked from the vine should be picked at the stricture in the stalk and not close up to the fruit.

Harvesting passionfruit.

Fruit can be gathered into plastic buckets or any other suitable containers.

When harvesting fruit from the ground in the early part of the season it is necessary to pick up two or three time a day, to avoid sunscorch of the fallen fruit. Passionfruit are very susceptible to sunscorch when freshly fallen, and regular picking-up is essential to achieve the maximum amount of export grade. Later in the season when there are fewer sunshine hours, and the sun is lower in the sky, picking up two or three times a week is satisfactory.

A new training technique on trial is to grow passionfruit on a pergola so that fallen fruit are not exposed to the sun and the necessity for several pickups per day can therefore be avoided.

Passionfruit for fresh market, especially export, should be handled with care to prevent abrasions to the rind and loss of bloom.

A dowling sorting table showing process grade passionfruit.

POST-HARVEST HANDLING

Passionfruit must be sprayed many times throughout the season, mostly with copper fungicides, for adequate disease control. As a result, at harvest there is often a spray deposit visible on the fruit. This can be removed by dipping in a 1% solution of hydrochloric acid, for 1½-2 minutes, or three quick dips. A plastic bucket with holes in the bottom, or a mesh basket, can be used for the dipping.

After the acid treatment the fruit must be washed in clean water (again three quick dips are sufficient) and then allowed to drain before further handling. To achieve this, fruit is usually tipped gently on to a slatted grading table.

At this point reject fruit destined for processing are removed. The remaining fruit for fresh market have the calyx remnants removed, and the stalk cut short to prevent damage to neighbouring fruit when packed in the tray. Remains of the calyx left attached are unsightly and can be a source of mould during transit in the closed container.

The fruit is dried with a fan drier, and rubbish blown away with a vacuum cleaner hose.

Fruit for export is then packed into single layer trays with plastic pocket pack inserts for counts 28, 32, 36, 40, and 44.

Passionfruit packed for export in a single-layer tray

Local-market fruit is usually packed into ¼ bushel or bushel cases.