Watermelon is an excellent source of income. There is a wide range of watermelon varieties available in the Ugandan market.

Nevertheless, farmers are recommended to choose early-maturing varieties that can withstand various challenges and have high yields. The market offers both open-pollinated varieties (OPVs) and hybrids.

Certain hybrids can produce fruits weighing as much as 11-14kg. These fruits are in demand in major local markets like St Balikuddembe, Nakasero, Kalerwe, and Nakawa, as well as regional markets in the country’s prominent towns.

Nursery

Seedlings are raised by placing seeds in planting pots, which can be easily obtained from agri-inputs stores nationwide.

The pots are filled with a well-prepared soil mixture consisting of high-quality soil and organic manure. It is important to place only one seed in each pot.

To ensure the growth of healthy seedlings, it is recommended to spray preventive fungicides and insecticides on the seedlings in the nursery. This spraying process should be carried out once a week.

In addition, it is crucial to water the seedlings at least once a day to provide them with sufficient moisture. After three weeks, the seedlings will be ready for transplantation.

Main Garden

Create furrows in the garden that are one foot wide and 15cm deep. Ensure that the furrows are evenly spaced 3m apart.

Plant the seedlings along the sides of the furrows, spacing them 60cm apart from each other. This should be done on both sides of the furrows.

Incorporate organic matter into the furrows and place a blend of DAP & Physiolith in the holes when transplanting.

For each hole, add 5g of the blend one to two weeks after transplanting, and then drench the root zone with Fertiactyl GZ (100ml per litre of water).

One month after transplanting, apply a top dress of NPK.

Remember to place the fertilisers at least three inches away from the stems to prevent root rot. At the flowering stage, spray a foliar fertiliser application (40ml in 20 litres). Make a second application after two weeks.

Diseases

Melons are always attacked by fungal diseases such as powdery and downy mildew.

Preventive sprays should be often using preventive fungicides such as copper or Mancozeb.

At least one spray can be done once a week in the dry season and at least two sprays in the wet season Dosage; 70g of Mancozeb in a 20-litre spray, 50g of copper in a 20-litre sprayer.

Pests

Aphids and melon fruit flies are the major pests of watermelon. Aphids suck sap from the leaves leading to curling of the leaves which eventually dry and lead to the death of the plant Dusban always works effectively to kill the aphids.

Melon fruit flies mainly manifest at the time of flowering. The adult lays eggs in the flowers which develop eventually into larva (maggot) at the time when the fruit has been formed. The larva eats up the cells of the fruit and bores into the fruit.

This results in fruit abortions, the rotting and bursting of fruits when they are not yet ready. Insecticides that control the fruit flies at this stage also kill the bees which we need for pollination.

The best remedy for melon fruit flies is to use fruit fly traps which attract only the fruit flies and kill them without affecting the pollination activity of the bees fifteen pieces of melon traps should be enough for an acre of land.

Harvesting

Watermelons should be harvested within a specific time frame, which is typically between 100 to 120 days after they have been transplanted.

It is important to ensure that the watermelons are fully ripe before harvesting. This can be determined by observing the fruit surface that is in contact with the ground, which should have a light yellow colour.

Another indication of ripeness is when the vine closest to the fruit starts to wilt. To prevent any damage to the fruit, the peduncle, which is the stem connecting the watermelon to the vine, should be carefully cut off. This is done to avoid any tearing or ripping of the fruit’s skin, as it can lead to the development of secondary diseases.

Watermelons are susceptible to cracking or bursting if they are not handled with care during and after harvest.

It is crucial to handle watermelons gently and avoid throwing them, stepping on them, or stacking them too high. Rough handling can cause damage to the fruit, leading to spoilage or loss of quality.