Fruiting, Harvesting and Post-Harvest 155
hand. One man can thus gather 3.5–4.5q daily. It is harvested by twisting the fruit
on Pusa Dwarf and Pusa Nanha trees; the operation can be done without mechanical
aids. Ladders are often used to harvest tall trees. It has been calculated that manual
picking and field sorting constitute 40% of labour cost of the crop. The mechanical
aid was tested and results indicated that a machine with one operator and two pick-
ers could harvest 450 kg of fruit per hour, equivalent of eight men hand-picking. The
latex oozing from the stem may irritate the skin and workers should be required to
wear gloves and protective clothing (DAIS 2009).
14.2 Yield
The yield varies widely according to variety, soil, climate and management of the
orchard. About 20–50 fruits are obtained from a plant and on an average fruit yields
vary from 50 to 75 tonnes per hectare in a season from a papaya orchard depending
on spacing and cultural practices during the first year and it reduces to be 20–25
tonnes per hectare in the second year. Maximum average fruit weight (1.20–3.05 kg),
length of fruit (22.45 cm), width of fruit (33.35 cm) and fruit yield (120.11 tonnes/
ha) were recorded when planting with a spacing of 2. 5 × 2.5 m in papaya cv. Coorg
Honey Dew was done (Singh et al. 2010). Fruits are stored in a single layer in bam-
boo baskets and covered with a thin layer of paddy straw and sent to local markets,
while for distant marketing, individual fruits are wrapped in newspaper and packed
in single-layer bamboo baskets and after putting saw dust as a lining material and
covered with a layer of paddy straw (Naturlande 2000).
14.3 Post-Harvest Management
Mature papaya fruits ripe within 2–4 days after harvesting. Paull (1993) reported
that ripening ranges from 7 to 16 days from the colour break stage. The rate of soft-
ening could differ between cultivars with respect to the rate of respiration, ethylene
production, skin degreening and flesh colour development (Paull 1993). Shelf-life
of fruit can be affected by several factors, namely, respiration, biological structure,
ethylene production and sensitivity, transpiration, developmental processes and
physiological breakdown (Irtwange 2006). It can be stored under controlled atmo-
spheric conditions, namely, 2% oxygen, 5% carbon dioxide and a temperature of
16°C can extend shelf-life up to 14 days. Fruits stored >20°C will be affected by
fungal diseases (Colletotrichum sp.) and <10°C by chilling injuries. Fruits can be
held at 30°C and high atmospheric humidity for 48 h to enhance colouring before
packing. Standard decay control has been a 20-min submersion in water at 49°C,
followed by a cool rinse. In India, dipping in 1000 ppm of aureofungin has been
shown to be effective in controlling post-harvest rots. An aqueous solution of car-
nauba wax and thiabendazole over harvested fruits gives good protection from post-
harvest diseases. Papayas must be treated before export to avoid introduction of fruit
flies. Fruits picked 1/4 ripe are pre-warmed in water at 43°C for about 40 min, and
then quickly immersed for 20 min at 48°C. This double-dipping maybe replaced
by irradiation. Fruits that have had hot water treatment, followed by irradiation at
75–100 krad and storage at 3% oxygen and 16°C for 6 days can be expected to have a