Pawpaws are flexible in their soil requirements. The main thing is good drainage. The soil must be well drained. Soil pH should be moderately acid to neutral, in the range of 5.5 to 7.0. Pawpaws are happiest in a rich, deep, loamy soil with high organic matter content.
In addition, they appreciate an organic mulch. In the wild, a natural mulching layer of decomposing leaves is normally present. Excessively dry sites should be avoided. Moist soils are ideal.
- The solo variety which produces small round sweet fruits with uniform size and shape. It is hermaphroditic and popular for both export and local market.
- The mountain variety grows at high altitudes with small fruits only suitable for jam and preserves.
- The sunrise variety that produces smooth pear shaped fruit of high quality, weighing 400 to 650 grams.
- The red royale that is an improved breed and give good quality yields.
- The vegetative propagated papaya using tissue culture resulting in superior plants that are disease resistant, high yields and are easy to maintain and harvest since the trees are short.
Tips for Planting A Pawpaw Tree
Help young seedlings and saplings establish themselves by fertilizing pawpaw trees with a balanced liquid fertilizer every few weeks for the first growing season. Afterward, use a granular fertilizer or a layer of compost in warm climates. Keep the area around the tree weed-free. Pawpaw trees can’t pollinate themselves, so you will need two different types of trees to produce fruit.
To further complicate matters, the insects that pollinate pawpaws aren’t efficient or abundant, so you may have to fertilize the trees by hand to get a good crop. When you can see a brown ball of anthers with yellow pollen grains in the flowers, it is time to gather the pollen.
Use a small, soft artist’s paintbrush to transfer the pollen from one tree to the stigma inside the flowers of another tree. The stigma is most receptive when the pistils are green and glossy and the anthers are hard and green.
Most flowers contain several ovaries, so each flower results in more than one fruit. Don’t overdo it! If you pollinate too many flowers, you’ll have to thin the crop to prevent the branches from breaking under the weight of the fruit.
Papayas start flowering when they are about one metre tall. The males flower first. Male flowers have long, thin stalks with several small blooms. Female flowers are usually single blooms, bigger, and very close to the trunk.
Cull most of the male plants. You only need one male for every ten to fifteen female plants to ensure good pollination.
And that’s it. You should end up with one very strong and healthy female plant per bed. (And a male plant somewhere…) If the weather is warm enough and if you are growing your papayas in full sun and in good soil, then you could be picking the first ripe fruit within 10 months.
The pawpaw plant has male, female, hermaphrodite (bisexual flower) and some other complex forms. Typically, the fruits from female plants have a short shape, while fruits from hermaphroditic plants are longer.
Female plants –These fruit trees grows female flowers only. Female flowers are usually single blooms, bigger, and very close to the trunk.
Male plants –These grows male flowers only. Male flowers have long, thin stalks with several small blooms.
Hermaphrodites trees –These grows both male and female flowers. Therefore allow 4 plants per hole and later thin out to single trees when flowers appear. You may need to consult your gardening advisor for identification of the flowers.
PESTS AND DISEASES AND THEIR MANAGEMENT
These parasites normally feed on the plant roots resulting to swelling of the roots. The plant becomes weak and as a result they fall off.
These are sap-sucking insects which attack the leaves and the flowers. They can be eliminated by use of horticultural oil. Organic mulch is also recommended to discourage the survival of these insects.
- Red spider mites
Red spider mites suck plant sap and this leads leaf defoliation, stunted growth and poor quality fruits. They leave spots on the fruits. Good farming procedures, including proper pruning and irrigation, are necessary to maintain their control. Note that insecticides are responsible for their expansion of these insects population. The use of horticultural oil is a recommended measure.
- Mealy bugs
They suck sap from tender leaves, petioles and fruits. They attack the leaves, flowers and fruits by sucking sap from these parts leading to stunted growth, leaf deformation and immature fruit drops. Biological controls such as ladybird beetles are used to control them.
- Birds and fruit bats
Birds feed mostly on the ripe papaya fruits. A control measure against birds would to harvest the fruits immediately they mature just before they ripen.
The white flies affects the leaves of the plant by sucking sap from them which results to curling and eventual defoliation of the leaves. Horticultural oils can be sprayed to reduce the infestation.
- Scale insects
They cause damage by feeding on twigs, branches and fruit injecting toxins into the plant. As they feed, they release white waxy coating which facilitates the development of sooty mold. Their populations are often kept in check by natural enemies, including predacious beetles and some wasps. Trees can be sprayed with pyrethrin which effectively kills the scales without damaging the natural enemies.
- Fruit fly
Fruit flies affect mostly the fruits. The adults lay their eggs under the skin of mature and ripening fruit. The eggs then hatch into maggots which feed on the flesh of the fruit causing it to rot and eventually fall off. Fruit flies can be controlled and eliminated using trap
Caused by fungus Colletotrichum gleosporoides. This Infection is characterized dark water-soaked lesions on the fruit during ripening later becoming circular sunken lesions with light brown margins. The disease is spread by wind and rain. The infection causes rotting of the fruits. Spray the appropriate copper based fungicides. Prevention involves pruning the dead branches of the affected tree before fungi produce spores and maintaining the correct conditions for the harvested fruits.
- Bacterial canker
Caused by bacteria Erwinia spp. Characterized by water-soaked lesions on leaves, witling leaves, particularly at top of canopy, water-soaked lesion and cankers on stem, cankers girdle stem and cause plant to collapse. Remove the affected parts and dispose them immediately to avoid the disease spread. Copper based fungicides could be used in cases of severe infections.
- Leaf spot
This a serious infection of the leaves which start as small yellow spots which expand with time and causes defoliation of the leaves in severe cases.
- Leaf curl
This infection is transmitted by whiteflies and causes curling, crinkling, vein clearing and deformation of leaves. In severe cases it causes defoliation.
- Powdery mildew
It is characterized by whitish fungal growth on various parts of the plant. This infection normally occurs in areas that are poorly drained. Always ensure good airflow around the plants and can be controlled by spraying with appropriate fungicides
- Papaya root rot
Root rot is caused by waterlogging.
- Papaya mosaic
This is a viral disease spread by aphids which is affects the young plants. It affects the leaves and fruits. It causes spotting on the areas infected. It causes stunted growth of the plants.
- Bunchy top
Causes water-soaked spots on leaves and stems and retarded growth of the plant resulting in a bunchy appearance to the plant. It is spread by pests such as the leafhoppers. As a control measure, choose the variety that is disease resistant. The pests spreading this infection could be sprayed by the appropriate pesticide.
- Papaya Ring Spot
This is another viral infection spread by aphids or be mechanically transmitted. It causes dark green rings on the fruits which become less distinct as the fruit ripens. The fruits may have uneven bumps and reduction of leaf size and plant growth is stunted. Ensure you maintain proper crop hygiene in all farm operations. Infected plants should be removed and destroyed.
Establishing Young Trees
For good fruit production the trees should be grown in full sun. While it is true that pawpaws are shade tolerant, they will fruit much less in the shade. Because of the large size of the leaves, windy sites are damaging and to be avoided.
Prepare the soil in advance of receiving your young pawpaw tree.
The soil from the hole should be thoroughly loosened to a fine tilth. The hole should be the same depth as the root system, and 2 or 3 times the diameter of the root mass. In an orchard setting, we recommend you plow a furrow down the row, rototill the soil to a loose tilth, and then mound the soil into raised beds.
Pawpaw trees do not have fibrous roots. Their roots are fleshy, similar to magnolia. And like magnolia, pawpaws transplant better if moved in the wet climates, not hot days.
For the first growing season keep the trees well watered. Do not over water, however. Drowning the tree is bad.
Keep the area completely free of weeds & all competing vegetation up to a 2-foot radius.
Weed control is essential to successful establishment.