MORPHOLOGY OF WATERMELON PLANT

Seedlings: The cotyledons are well developed, the leaf blade is elongated, the tip is indented, about 20 mm long and 10 mm wide, slightly thick and a prominent main vein. The first leaves grow alternately and simply, carried by a 10-15 mm petiole with fine hairs. The leaf blade is cut crosswise into 3 to 5 round pinnate lobes.

Mature plant: Grass, annual, creeping on the ground, can climb the trellis thanks to the tendrils, split into 3 parts developing at the end of the petiole. The main axis is branched and can measure many meters in length, the stem has fine white hairs.
Roots: including the main root, an axis around which secondary roots grow horizontally.

Leaves: leaf blades are green, single and alternate, with hairs on the underside, carried by a 5 to 15 cm long petiole covered with fine hairs, especially on young leaves. The leaf blade is usually oval and about 10-15 cm long and 7-12 cm wide. Split at the base into pinnate lobes of 5 to 7 lobes. The leaf margins are cut and uneven. The secondary veins on both sides of the main vein are different segments. Both upper and lower surfaces are rough. The tendrils are due to leaf deformation to adapt, cling and climb on different calyxes.

Flowers: solitary, yellow, grow in the leaf axils, the flowers are carried by a 15-20 cm long flower stalk, also covered with white fine hairs. Flowers are monoecious, monoecious, male and female flowers on the same tree:
Male flower: bell-shaped sepal, 5 sepals, 5 oval petals, about 4 cm long, yellow, pointed tip, 3 pistils, S-shaped anthers, with fine hairs.
Female flower: petals attached at the top of the ovary, 1 spherical chamber.
Fruit: very large, varied, ovoid to spherical, can reach 15-25 cm in diameter, with light green, dark blue or yellow flowers. The fruit inside is red or yellow flesh, many flat seeds, brown or black
Seeds: inverted ovoid, 10 mm long, 5 mm wide, 2 mm thick. When mature, the seed coat is smooth, white or brown.

ECOLOGICAL CONDITIONS OF WATERMELON

– Watermelon originates from hot climates, prefers warm, dry climates, full of sunlight to help bloom many female flowers and produce fruit that ripens early, high yield. Low temperatures cause the plant to grow weakly, easily fail, heavy rains cause the roots to rot and die, making it difficult to flower, making it more difficult to pollinate and set fruit, when fruit has set, the fruit is easy to rot, poor quality, the higher the humidity, the easier it is to get diseases. When there are storms, low temperatures, high humidity, the stems and leaves are easily crushed and quickly withered, making it difficult to grow.

– The suitable temperature for growth is 25-30oC, so it is very easy to grow in the dry season in the Mekong Delta. The suitable temperature for flowers to bloom and pollinate is 25oC, the suitable temperature for large and ripe fruit is 30oC.