A. Transplanting stage:
When the seedling is 10-15 cm tall, it should be transplanted, but 30-40 cm is also all right if it is grown in a larger container.
A 40-60 cm high bed is required if the soil is not well drained. Normally, the distance between
rows is about 2-2.5m, and 2m between plants ( or 3m x 3m when grown at sloping land, or
2.7m of distance between beds for the tractor practice). The total number of plants for each hectare is about 2,000 to 2,500. In case of eradication of undesirable sexual or virus infected plants later, the distance between plants at beginning of planting may be 1.2-1.5m.
C. Pollinator plants:
Minimum 10-20% hermaphrodite plants are required for pollination.
D. Planting method:
(A) Black-and-white plastic mulching film on the beds can be used to:
(a) reduce the loss of water and fertilizer nutrients
(b) control weed
(c) repel the winged aphids
(d) decrease virus infection at young stage and
(e) decrease bed soil erosion.
(B) Drill the planting hole about 45cm in diameter and 30cm in depth. The soil in the hole is mixed with
compost for planting. Then transplant the seedlings (seedlings should be fully watered one day before
transplanting) on a cloudy day or late afternoon to minimize transplanting shock. Take care not to plant
too deep, otherwise collar-rot disease may affect the buried part of the stem. Then water immediately
(C ) Intercrop with the newly-planted long term fruit tree such as mango or orange. Short term
crop such as corns or vegetables may also be considered but not necessary.
(D) To retard growth, lower the fruit-setting site, resist the wind and facilitate management and harvesting, slant
planting is considered as follows:
Plant the seedlings at an angle of 45° between the stem and surface of the soil and then later cut the
leaves which touch the soil. Fix with rope at two thirds of the stem from the base and adjust the site up
when the plant grows higher to prevent the stem from being upright. Above procedures may be modified
to fix the plant with plastic rope down to the side(s) of bed about 1-2 months after transplanting (about
36-40cm height of the plant).
(E) Screen house cultivation: For reducing virus infection during growing period, the following cultivation is
Use 3.0-3.6m long of bamboo stems or concrete stakes as supporters at a distance of 4.5-5m, and
connect with No.12 iron wire. Then tightly surround with 32-mesh white net which contains anti-ultra
violet material. After the construction is completed, the protected healthy seedlings are planted and the
virus-infected plants destroyed and buried immediately once found. Note that hand pollination for female
trees is required (the central flower of the cluster on the bisexual plants can be taken as pollen supplier)
and control the powdery mildew and mites well. The net may be taken off before the fruit is mature.
The plant needs continuous fertilization as fruiting is continuous upon maturity. Recommended rate of fertilizers for papaya is as follows: (It should be modified depending upon the soil conditions.)
A. Basal fertilization:
Apply 10 tons of fermented compost per hectare (or 1kg per square meter) before planting or when forming
beds. The same dose should be repeated every year for the adult plants.
B. Side dressing:
Apply NPK at rate of 4:8:5 monthly, bimonthly or seasonally. Following fertilizers in kg is for 100 plants in the period:
Age (NH4)2SO4 Ca(H2PO4)2 KCL Total Frequency
within 6 months 5.6 12 2.4 20 2-3
between 6-12 months 25 54 11 90 2-3
between 1-2 years 35 75 15 125 4-6
between 2-3 years 58 134 20 212 4-6
Apply 0.25-0.5kg borax per 100 plants right before dry season in soil which is boron- deficient. For the
young trees, apply compound fertilizers in the trench (10 cm deep and 15 cm wide) around the outer of tree
crown, then fill back the soil. As for the adult trees, apply in the trench (10 cm x 15 cm) at both sides of the
tree and fill back the soil, or top dress at furrows after irrigation.
VI. Weed control
Weeds should be removed at the young stage frequently and lightly, but never do deep tillage to the soil since the plant has shallow roots. Growers may apply herbicide once before emergence with 43% Lasso E.C. at 1:200 or 80% Kamex W.P. at 1:400; or mulch the bed with plastic film before transplanting or with rice/sugarcane straws before or within a few days after transplanting to control the weeds, soil erosion and water loss.
Normally, irrigate every 10 days in winter or every week in summer, but practice varies according to soil, climate conditions, and irrigation methods. Ring method, furrow or drip irrigation can be done. However, be sure to prevent the water from coming in contact with the stem. Irrigation may prevent the plants from the damage of frost.