Horticulture Principles and Practices

variable, ranging from creamy yellow pink to orange reds. The fruit wall (rind) thickness
is between 1–4 cm of white inner flesh between hard outer skin and softer pulpy
interior.
Watermelon varieties vary in maturity days between 75–120 days. The average size
is about 40 lb., however, the so-called “ice box” cultivars weigh only about 20–25 lb.
Seedless melons are triploids produced by the crossing of 4n × 2n.
Major producing states for fresh market watermelons are Texas, Georgia, Florida,
California, and North Carolina, in this order of descending importance.
The crop is frost intolerant. Production areas must have between 85–150 frost-free
days and a high daytime temperature of 25–33C° (77–95F°), and nighttime temperature
of 17–25C° (62–77F°). Soil pH of 6.0–6.8 is desirable for watermelons. Watermelon is
monoecious. Proper fruiting is aided by bees as pollination agents.
The crop is grown on raised beds in the western United States and in the East. The
beds are spaced 80 inches from center to center. Closer spacing results in smaller fruits.
For premium yield, watermelon is grown with irrigation and mulching. The crop is
established primarily by direct seeding. However, because of poor germination, seedless
melons are transplanted.
The crop is moderately fertilized with nitrogen mainly, but with some phosphorus
and potassium as the soil test may reveal. Excessive nitrogen produces vegetative growth
and delayed reproductive growth that can lead to reduced fruit setting.
The fruits are mature when the ground spot changes color from white to pale
yellow. The general color of the rind also changes from glossy to dull green. Another sign
of maturity is when the tendril at the same node as the fruit dies. Unlike muskmelon,
watermelons do not slip or detach from the stalk when mature and ripe. They have to be
cut by hand. The sugar content of the fruit at maturity ranges between 9–13 percent.
Shelf life is 10–14 days, if not refrigerated.
Diseases and insects common to watermelon production include anthracnose,
fusarium, downy mildew, pickleworm, rindworm, and corn seed maggot.
20.10.4 PUMPKIN (CUCURBITA PEPO)
Pumpkin or squash? Just like muskmelon or cantaloupe, the distinction between pumpkin
and squash is debatable. Some consider C. pepo as true pumpkins, while all C. maxima are
considered as squash. Pumpkin is one of the most visible festive fruits in the United
States, being associated with Halloween as a fresh fruit, and other occasions in which
pies are served. It has a distinct appearance and bright orange color when ripe. The flesh
of pumpkin is coarse and has a strong flavor. It is used as livestock feed and of course as
pumpkin pie.
Squash, winter and summer species, have fine-grained flesh that has a mild flavor
and is baked or cooked for food for humans. Summer squash is used as an immature fruit
and can be also be fried. Summer squash is early maturing, usually attaining maturity in
45–60 days. Winter squash and pumpkin mature in 80–120 days.
Pumpkin cultivars are classified according to use as follows:
1. Mini pumpkins. very small size and used for desktop decoration; it has a flattened
shape and light orange color.
2. Baby pumpkin. these are also used for desktop decoration; it is small sized and
dark orange in color.
3. Pie pumpkin. this weighs 5–10 lbs and has a near global shape; it is used for
decoration and cooking.
4. Multipurpose. it has naked seeds that are edible; the flesh is used for cooking
while the rind is carved.
5. Carving pumpkin. this is also called a Jack-o-lantern pumpkin and weighs
between 15–25 lbs and has variable shapes.
6. Exhibition pumpkin. this is enormous in size, weighing more than 100 lbs;
this C. maxima species has a smooth surface and pale orange color.
20.10 Growing Cucurbits 637