Muskmelon

Melons are in the gourd family or Cucurbitaceae. It is not clear whether they originated in Africa or Asia. Melons (Cucumis melo) are grouped into the general categories of muskmelons, true cantaloupes, and winter melons. It is possible to cross these three C. melo types and the resulting seeds will produce plants with characteristics of more than one group. Crossing is not a problem in terms of production, however, because as long as sufficient pollen is available, the fruit will develop normally.

For example, a flower on a muskmelon will develop into a typical muskmelon fruit even if honeydew pollen was deposited. The seeds may, however, develop into plants with characteristics of both types of melons. C. melo group reticulatus. Heavily netted, this is the cantaloupe sold in grocery stores, which is properly referred to as a muskmelon.

C. melo group cantalupensis. This is the true cantaloupe, which is less netted, and is not grown commercially in the United States.

C. melo group inodorus. Melons in this group ripen slowly so their shelf life is much longer than muskmelons. This group, which is sometimes called 'winter melons,' includes many large melons: honeydew, casaba, Crenshaw, Santa Claus melon, Persian melon, and Juan Canary. Size, shape and color vary significantly. The honeydew, the most important melon in commercial terms, has a round shape and greenish-white skin and flesh. The Persian melon is round, orange-fleshed and has a fine surface netting, like a muskmelon. Most of the other melons are football-shaped with an unnetted, yellow-green or striped skin, and yellow or white flesh.

Flowering Characteristics

Muskmelons are andromonoecious, first producing groups of male flowers in leaf axils, then producing single perfect flowers. Perfect flowers are those having both male and female organs. The main vine grows about 18 inches without branching and produces only male flowers. It then branches and each branch of the main stem bears 1 to 2 perfect flowers near the connection to the main stem. Under favorable conditions, these perfect flowers and those formed on the main stem just before branching form what is called the 'crown set'. Heavy crown set is desirable because of the early harvest and generally better market prices, high fruit quality and concentrated maturity. When crown fruit set, all the remaining nodes on the stem or branch produce only male flowers, at least until crown fruit are harvested. If the crown fruit do not set for some reason, fruit is set further out on the branches instead. This pattern is repeated as each new branch forms so, in theory, many fruits could be set on a single plant, forming circular ripples of developing fruit around the original vine. In practice, however, only one to four fruit mature on each plant because previously set fruit inhi-bit the growth of younger fruit. If additional fruit are set, fruit size and soluble solids are generally reduced in proportion to the increased set.

Climatic Requirements

Muskmelons are warm-season crops, requiring 80 to 120 days of warm, preferably dry weather to mature. Muskmelons are planted April 15 to 20 in coastal North Carolina, and 2 to 3 weeks later in western North Carolina. Best melon quality is obtained in areas with high temperatures, high light, minimal rainfall during the growing season (assuming irrigation will be used), and low humidity. Very high temperatures (110 to 115 degrees F) cause vines to temporarily wilt, resulting in sunburned fruit with a reduced shelf life. Cloudy and rainy periods during fruit maturation are likely to lead to poor quality (low sugars). Fungal diseases often defoliate crops in humid areas such as the southern states, resulting in small or cull fruit, poor netting, sunburn, bland taste and low sugar. The highest quality melons come from the Southwest and California where light is high, relative humidity is low, and water is supplied by irrigation rather than rainfall.

In cool-spring areas, such as the northeastern United States, row covers are sometimes used on melons to promote earliness. In the South results are variable and row covers are often not economical or even advantageous due to unpredictable spring weather conditions. Even in the early spring, occasional warm days can raise temperatures inside the covers above 90 degrees F, which is too high. Most areas in the South do not experience long, cool periods once the threat of frost is past. While row covers also offer insect protection, this is more important for the fall than the spring crop. In any case, covers must be removed once female flowers open or the fruits cannot be pollinated.