Sites and soils
Watermelons do well on sandy loam soils which are well drained and slightly acid. When planted on very heavy soils, the plants develop slowly, and fruit size and quality are usually inferior.
They do well at temperatures between 22 and 28 degree centigrade. Stagnation of growth occurs at temperatures less than 15degree centigrade.
Optimum rainfall requirement per cropping season is 600 mm and 400 mm is considered minimum. Excessive humidity may favor leaf diseases and also affect flowering.
Watermelon is propagated by: Seeds, directly planted in the field. Seeds is the most preferred method if you are in a warm region in Kenya.
Instead of planting directly in the field and have 3 weeks of accumulated weeds germination and insect attacks to battle with, planting of seeds in seed trays in a protected area for later transplant into the field when at least 2 permanent leaves have developed, is a very viable option. Watermelon is grafted in some production areas
Watermelons in Kenya are grown throughout the year in lowland areas but peaks of rainy season should be avoided. The holes are dug at a distance of about one meter within the row and about 2 meters between the rows. Plant 2 seeds per hill, placing them 3 to 4 cm (1.5 inches) deep into the soil.
Watermelons produce separate male and female flowers. Male flowers are produced initially, followed by production of both sexes usually at a ratio of 1 female to 7 males. Watermelon flowers are viable for only one day hence important to have pollinating insects.
To be done regularly to keep the field clean. Avoid injuring the plants when weeding.
Fruit pruning-Remove blossom-end rot fruits to promote additional fruit set and better size of the remaining melons. If a market demands larger melons, remove all but three or four well shaped melons from each plant. To avoid disease spread, do not prune melons when vines are wet.
Harvesting usually begins 3-4 months after planting. Maturity is sometimes difficult to determine. Useful maturity indicators are listed below. Maturity indicators include:
The change from white to cream or pale yellow of the skin area where the melon has been resting on the soil
A dull hollow sound when the fruit is tapped with the knuckles
Ensure minimum handling of melons, as extra handling is expensive and may harm the fruits.
Rotation-Watermelons can be rotated with cereals, legumes or cabbages
- Flea Beetles
- Red spider mites
- Damping-off diseases
- Root-knot nematodes
- Powdery mildew