Abelmoschus esculentus
Last revised February 12, 2010
Okra is not well adapted to Oregon climatic conditions as it requires high soil temperatures and high day and night temperatures for best production. Okra may be grown in the warmer parts of the state when special efforts are made to provide the proper environmental conditions. This would include the use of plastic mulch and wind breaks to improve temperatures around the plant and in the soil. The costs of these techniques probably limit commercial production of okra to market garden and direct marketing situations.
VARIETIES
Green types:
Blondy, 48-50 days, dwarf plant 3' high, spineless, ribbed, lime-green.
Prelude, 52 days, plants 3-4' tall.
Clemson Spineless, 55 days, plants 5' tall, pods 5-6" long, large diameter, most commonly available variety.
Emerald, 55 days, plants 5' tall, pods to 8" long, small diameter.
Perkins Mammoth Long Pod, 60 days, plants 6 to 10' tall, pods 7-8" long, intense green.
Cajun Delight
Green Best
Red types:
Red Okra, 55 to 65 days, 3 to 4' tall, bushy plants with 6 to 7" pods.
Red Velvet, similar to Red Okra.
Burgundy
SOIL
Well drained, sandy soils are preferred. Addition of manure or other organic material is usually beneficial on such light-textured soils. Okra grows best in neutral to slightly alkaline soils, pH 6.5-7.5.
TEMPERATURE REQUIREMENTS
Okra is a tropical plant requiring warm growing conditions. Commercial production is recommended only in the warmest portions of the state. Night temperatures should be above 55 F for good growth.
Minimum soil temperature for germination is 60 F. Optimum soil temperature range is 75-90 F.
SEEDING
Okra seed numbers approximately 8,000 per pound. Use approximately 8-12 lb seed/acre. Plant 1 inch deep, 4-6 seeds/foot of row. Thin to desired spacing when plants are 3 inches tall.
Germination many be enhanced by soaking seeds several (4-6 hours) hours or overnight immediately before planting. The seed will need to be surface dried for mechanical planting.
SPACING
Rows 36-48 inches apart, 12-24 inches between plants. Tall or spiny cultivars require wide spacing.
TRANSPLANTING
Growers interested in early fresh market or in short growing season areas may find it profitable to transplant. Sow seeds in 2-inch pots or cell-packs, 3 seeds per pot, 1/4 inch deep, 4-5 weeks ahead of transplanting. Thin to 1 plant per pot or cell.
FERTILIZER
For the most current advice, see Nutrient Management for Sustainable Vegetable Cropping Systems in Western Oregon, available as a free download from the OSU Extension Catalog
The following are general recommendations. Before planting apply:
Nitrogen: 30-50 lb/acre applied at planting. Side dress with an additional 35-50 lb N/acre when plants are 8-10 inches tall, or use 25 lb N/acre after first fruit set and again after 4-6 weeks at the same rate. Adequate nitrogen is necessary to ensure a long harvest period; however, excessive rates are to be avoided as they can cause okra to become excessively vegetative.
Phosphorus: 50-100 lb/acre, all applied at, or before planting.
Soil pH should be maintained above 6.0 and, preferably, near 6.5.
IRRIGATION
Okra requires adequate soil moisture throughout its entire growing period if optimum growth and yield are to be obtained. Avoid heavy early irrigations as these can cool the soil and slow development.
PLASTIC ROW COVERS AND MULCHES
Black plastic mulch may increase soil temperatures, will control weeds, and conserve moisture, increasing yield and earliness. For black plastic mulch to increase soil temperature, it is critical that the soil surface be smooth and that the plastic adhere to the soil surface. This can only be accomplished with a plastic laying machine designed and adjusted properly for this purpose. Clear plastic mulch is very effective at increasing soil temperature but does not control weeds.
A new generation of plastic mulch films allows for good weed control together with soil warming that is intermediate between black plastic and clear film. These films are called IRT (infrared-transmitting) or wavelength-selective films. They are more expensive than black or clear films, but may be cost-effective where soil warming is important.
A new generation of plastic mulch films allows for good weed control together with soil warming that is intermediate between black plastic and clear film. These films are called IRT (infrared-transmitting) or wavelength-selective films. They are more expensive than black or clear films, but may be cost-effective where soil warming is important.
Plastic, spunbonded, and non-woven materials have been developed as crop covers for use as windbreaks, for frost protection, and to enhance yield and earliness. They complement the use of plastic mulch and drip irrigation in many crops.
Non-woven or spunbonded polyester and polypropylene, and perforated polyethylene, row covers may be used for 4-8 weeks immediately after transplanting. Covers should be removed when plants begin to flower to permit proper pollination. Row covers can increase heat unit accumulation by 2-3 times over ambient. Up to 4 F of frost protection may also be obtained at night. Soil temperatures and root growth can also be increased under row covers as are early yields, and in some cases total yields.
HARVESTING, HANDLING, AND STORAGE
Okra pods should be harvested while still tender and before the seeds are half grown. This is usually 5-6 days after flowering. Pods with tips that will bend between the fingers without breaking are too tough for use as fresh fruit. Consumer preference demands pods 2.5-3.5 inches long. Okra should be harvested about 3 times each week. Regular picking increases yield. Remove and discard old pods from the plant as such pods will retard pod set and reduce total yield. Under good conditions 300 to 400 lb might be obtained per picking per acre. In the warmer, longer season areas of Oregon (the Columbia and Snake River areas) okra might be harvested over a 50 to 60 day season.
Okra plants and pods may have small spines to which some people are allergic. Pickers should wear gloves and long sleeved shirts as skin protection.
STORAGE (Quoted or modified from USDA Ag. Handbook 66 and other sources)
Hold okra at 45 to 50 F and 90 to 95 % relative humidity. Okra deteriorates rapidly and is normally stored only briefly to hold for marketing or processing. Large quantities are canned, frozen or brined. It has a very high respiration rate at warm temperatures and should therefore be promptly cooled to retard heating and subsequent deterioration.
Okra in good condition can be stored satisfactorily for 7 to 10 days at 45 to 50 F. At higher temperatures toughening, yellowing, and decay are rapid. A relative humidity of 90 to 95 % is desirable to prevent shriveling. At temperatures below 45 F, okra is subject to chilling injury, which is manifested by surface discoloration, pitting, and decay. Holding okra for 3 days at 32 F may cause severe pitting. Contact ice or top ice will cause water spotting in 2 or 3 days.
Fresh okra bruises easily, the bruises blackening within a few hours. A bleaching type of injury may also develop when okra is held in hampers for more than 24 hours without refrigeration. Storage containers should permit ventilation.
Prepackaging in perforated film is helpful. both to prevent wilting and physical injury during handling. Results of a packaging study suggest that 5 to 10 % carbon dioxide in the atmosphere lengthens shelf life by about a week. Higher concentrations of carbon dioxide caused off-flavors.
PACKAGING
Okra is shipped in bushel hampers or crates, holding 30 lb net; 5/9-bushel crates, 18 lb net; 12-quart baskets, 15-18 lb net; or loose pack in cartons or L.A. lugs, 18 lb net.