The optimal temperature range for papayas in South Africa is between 25°C and 28°C, and production normally peaks between September and November.
Papayas grow and produce well on a wide variety of soil types. Under favourable conditions, the root system can penetrate to a depth of 2m, but most of the roots responsible for nutrient uptake are found in the top 500mm.
Correct irrigation is crucial (see table for water requirement guidelines).This starts with good drainage. Papaya roots
will die off in over- saturated and poorly drained soil. Impermeable layers will hamper growth and production and can lead to root diseases.
Papayas grow best on a slight slope, which enables the runoff or drainage of excess water and prevents waterlogging.
Soil depth: Under irrigation, papayas grow best in soil with an unimpeded depth of more than 1m. However, if irrigation is well-planned and managed, there should be no problem on soil with an unimpeded depth of 750mm, provided that drainage is good.
Texture: The ideal soil for papaya cultivation under irrigation is a sandy loam or loam soil with a clay content of 15% to 30%. Soil with a clay content of up to 50% is also suitable. In very sandy soil, temporary over-saturation might occur when soil compaction or impermeable layers limit drainage. Sandy soil (less than 10% clay) normally has a very low water-holding capacity and nutrient status. A mulch or application of organic material can greatly increase the potential of such a soil. Seek expert advice here.
Soil structure: The ideal soil has a fairly loose, brittle, crumbly structure.
Soil pH (water): Papayas grow best in soil with a pH (water) value of 6 to 6,5. If soil exchangeable aluminium (Al) is not more than 30ppm, a soil with a pH (water) of 5,5 or higher may be used. At a pH (water) value lower or higher than the 5,5 to 7,2 range, plants may suffer from trace element, phosphate or potassium deficiencies.
Proper soil preparation will ensure optimal conditions for root growth that can last the lifespan of the plant. It also offers the following advantages:
- Better root development;
- Improved soil drainage; and less runoff;
- More effective irrigation and rainfall use;
- Better nutrient use;
- Greater tolerance toward disease;
- Improved fruit size;
- Increase in yield;
- Prolonged economic lifespan.
Soil analysis and nutrients
Obtain a soil analysis (your extension officer will be able to help you here) before planting. Supply the lime, phosphate and other elements as recommended by the analysis.If lime is needed, incorporate it into the soil six months to a year before planting. If it is necessary to rip the soil, plough the lime in beforehand and then rip afterwards.
Some producers prefer to plant a cover crop as a source of organic material. In such cases, plant it about six months before the actual soil preparation begins.
Source: Directorate Agricultural Information Services, DAFF, in co-operation with the ARC-Institute for Tropical and Subtropical Crops. Please note, the foregoing is merely intended as an overview of papaya production.