RIBBED GOURD

DESCRIPTION

Both luffas have value as food items, but are seldom eaten in Florida. Most gardeners grow them for their fibrous interior, which is useful as a rough cloth or sponge for cleaning and scouring. The two species are somewhat similar in appearance. Both are vigorous, climbing, annual vines with several lobed cucumber-like leaves. When crushed, the leaves give off a rank odor.

Both male and female flowers occur on the plant with a much greater number of male flowers. The rather large male flowers are bright yellow and occur in clusters. The female flowers are solitary and have the tiny slender ovary attached. Angled luffa flowers appear later in thday than the smooth type and stay open through the night. Bees pollinate the flowers. Leaves are covered with short stiff hairs. Smooth luffa fruits are shaped like cucumbers but are larger, 1-2 feet in length and 4-5 inches thick. The exterior is green, sometimes mottled, and smooth with longitudinal lines. Fruits of the angled luffa are characterized by sharp, elevated ridges running the length of the pods. The interiors of both are cucumber-like when immature, but quickly develop a network of fibers surrounding a large number of flat blackish seeds. Smooth luffa seeds are a bit more narrow and have a pitted appearance.

Common name
Ridged luffa, vegetable sponge, chinese okra, gambas, lu-fa risada, california okra, strainer vine, calabaza de aristas, sukwa, to gado hechima, concombre papengaie, petola sagi, ling jiao si gua, sze gwa sigua, vegetable sponge, belustru, ketola, patola, angled luffa, smooth luffa.

varities

  • L. acutangula (Angled luffa, Ridged Luffa)
  • L. aegyptiaca (Smooth luffa, Egyptian luffa)
  • L. operculata (Sponge cucumber)

Distributional range:

Native:

  • ASIA-TROPICAL
    Indian Subcontinent: India [probably indigenous fide Burkill]; Pakistan

Other:

  • naturalized throughout tropics & subtropics

Classification:
Luffaacutangula (L.) Roxb.

.

Kingdom / Plantae – Plants
Subkingdom / Tracheobionta – Vascular plants
Superdivision / Spermatophyta – Seed plants
Division / Magnoliophyta – Flowering plants
Class / Magnoliopsida – Dicotyledons
Subclass / Dilleniidae
Order / Violales
Family / Cucurbitaceae – Cucumber family
Genus / Luffa Mill. – luffa
Species / Luffaacutangula (L.) Roxb. – sinkwa towelsponge

Propagation
Seeds.

Culture
Full sun, Luffa is cold sensitive and should be grown during the warm season.

Luffa is a warm season, cold sensitive genus originating in India. Both species grow throughout the tropics, including subtropical Florida. Luffa is grown mostly as a novelty in Florida gardens. However, some have been tried commercially for the sale of the sponges. Being cold sensitive, luffas should be grown during the warm season.

Temperature range

temperatures in the range of 18° to 24°C, with daytime highs of 30° to 35°C

soil

, good drained sandy loam

soil pH

Slightly alkaline

Planting

Planting can be established by direct seeding or transplanting. Grow transplants by a method that will avoid disturbances of the root system during planting. Plants should be set in the field at the 2 to 3-true leaf stage. When direct seeding, place the seed 1 inch deep - the objective is to have a final stand of plants placed about 18 to 24 inches apart in the row.

Spacing

Luffa requires a lot of space, so plant seeds in hills spaced 6 feet apart or space plants about 3-4 feet apart in a single row.

irrigation

Irrigation practices should be managed to maintain good soil moisture in the top 18 inches of soil where the major root system is located. Drip irrigation can be used successfully on Luffa plantings and provides the most efficient use of water.

Fertilizer

Prepare the soil and fertilize just as you would for squash or cucumbers. Fruits touching the soil develop decay so mulch will be helpful. Apply one-third of the nitrogen and all the phosphorus before planting, either broadcast and disked in, or in a band a few inches to the side and below the plant line. Animal manures can be applied and incorporated a few weeks prior to planting to supply part of the nutritional requirements.

Pests.

All cucurbits are susceptible to many of the same diseases and insect pests, such as nematodes, viruses, powdery mildew, leaf miners and spider mites.

A pesticide used on Luffa must be specifically labeled for use on that crop, or for cucurbits in general. An amendment to the federal pesticide regulations (June 29, 1983) groups several minor cucurbits, including Luffa, so that residue tolerances for pesticides labeled for use on cucumbers, muskmelons, and summer squash could be used on Luffa if the pesticide manufacturer chooses to obtain a group residue tolerance and include that on the label.

Harvest and postharvest practices.

The basic method for preparing the sponge material is to immerse the dry, mature fruit in water for a few days to soften the skin and flesh so that it can be easily removed. Other processing methods include freezing or using boiling water. Once cleansed of seeds and flesh, the fibrous network is dried and, for some purposes, bleached in hydrogen peroxide. Various varieties are available that differ in diameter, length, and quality of fiber. Immature fruit of sponge gourd is rarely used for food in this country, but in India sweet varieties are grown for this purpose.

Immature Luffa fruits harvested for food purposes are likely to be susceptible to chilling injury, similar to cucumbers and summer squash, consequently refrigerated storage should not be below 50°F. Storage conditions have not been studied for Luffa fruits, but storage is probably relatively short. To maintain the best quality, it is suggested that fruit be marketed within a few days following harvest. Young fruits have tender skin, thus care should be taken during harvest and packaging. Fruits should be cut from the plant rather than pulled to avoid plant damage.

Yield.

Reports form Japan and India indicates that for sponge production a good yield is about 25,000 fruits per acre. On this basis, with a plant density of 4,400 plants per acre (24 inches in the row on 60 inch spacing), the number of fruit per plant should be limited to five or six.

USE

Small (less than 6 inches long) young luffa gourds are used as a vegetable either prepared like squash or eaten raw like cucumbers. Some varieties are sweeter than others, particularly of the smooth type. Bitter types should not be eaten, as some poisonous properties have been reported.

However, best sponges come from mature-green fruits, although dry fruits may be used. The fruits should be soaked for several days and then peeled. Once cleaned, the sponges should be bleached and then dried in the sun. Sponges have been used for cleaning, filtering, and bathing.

ECONOMIC IMPORTANCE

Currently 20,981 economic impact records exist in GRIN for the 14,114 taxa for which economic plant data are provided. GRIN economic data are classified to two levels adapted from the Economic Botany Data Collection Standard (Cook, 1995). A total of 16 classes are recognized, including 13 from this Standard: food, food additives, animal food, bee plants, invertebrate food, materials, fuels, social uses, vertebrate poisons, non-vertebrate poisons, medicines, environmental uses, and gene sources, with the addition of classes for weeds, harmful organism hosts, and CITES-regulated plants. Note that two of these added categories plus vertebrate poisons do not represent beneficial uses, but are mostly negative in their economic impact. The 16 classes are further subdivided into 113 subclasses. Sources of economic data are referenced in GRIN. A thorough discussion of GRIN economic data can be found at World Economic Plants: A Standard Reference.

Leaf

Medicines: antidotes (venomous stings, bites, etc.); anus, haemorrhoids; cutaneous, subcutaneous parasitic infection; generally healing; leprosy; menstrual cycle; skin, mucosae

Leaf-sap

Medicines: eye treatments

Root

  • Medicines: dropsy, swellings, oedema, gout
  • Phytochemistry: alkaloids

Root seed

  • Medicines: laxatives, etc.

Seed

  • Phytochemistry: fatty acids, etc.; glycosides, saponims, steroids; miscellaneously poisonous or repellent

Seed-cake

  • Agri-horticulture: composting, manuring