Production Practices

Soil preparation 

Okra is planted onto raised beds covered with black plastic mulch. Soil needs to be cultivated and granular fertilizer worked into the soil prior to forming beds.

Okra is susceptible to soilborne pathogens such as Verticillium and Fusarium wilt. An effective strategy to combat these diseases is through fumigation of the land in the fall of the year prior to planting. Vineland investigated the effect of fumigation on the marketable yield of okra. Results indicate up to a 500 per cent increase in marketable yield when the soil was fumigated in the fall prior to planting (Figure 1). 

Yields of okra varieties on fumigated and non-fumigated land

Figure 1: Yields of okra varieties on fumigated and non-fumigated land.

Our research indicates that it is not feasible to grow okra without fumigation on land where soilborne pathogens such as Verticillium and Fusarium are present.

Fertility 

Adequate soil fertility is critical to healthy and vigorous plants, especially for maintaining high levels of production. Trials conducted in 2015 and 2016 at Vineland indicate okra plants respond best to 75 kg/Ha of nitrogen (Figure 2). It is recommended to apply 50 kg/Ha of nitrogen pre-planting and an additional 25 kg/Ha through fertigation during the growing season. Fertigation should be applied weekly from the time the first flower blooms up to the end of August. Approximately 5 kg of nitrogen in the form of potassium nitrate is recommended per hectare per week.

*Nitrogen rates exceeding 75 kg/Ha may negatively impact plant performance and lead to lower yield.  

Figure 2: Marketable okra yields in response to increasing rates of nitrogen.

Figure 2: Marketable okra yields in response to increasing rates of nitrogen.

Seeding/transplanting 

In tropical and subtropical climates, okra can be effectively sown directly into the soil. However, as the growing season in Canada is shorter, okra is commonly established by using transplants.

The impact of direct seeding okra on yield was assessed over two growing seasons. Production by direct seeded okra was 12 to 20 per cent lower than that of transplanted okra. While this is not a significant decline, in general, okra plantings established from transplants offer growers an earlier and more abundant harvest (Figure 3).

Okra yields when planted using direct seeding or greenhouse-grown transplants

Figure 3: Okra yields from direct sown seed compared to greenhouse-grown transplants.

Season extension 

Floating row covers and perforated plastic are important tools in extending the season (i.e. allowing plants to be sown/transplanted earlier) and protecting young plants from adverse weather conditions after transplanting. Some varieties respond better to row covers than others as seen in Figure 4.

Marketable yields of okra left uncovered, under floating row covers and under perforated plastic

Figure 4: Marketable yields of okra when transplants were left uncovered (black plastic) or initially grown under floating row covers and under perforated plastic.

Plant spacing 

To maximize the yield potential of okra, it is essential to optimize spacing. To obtain the highest yield potential, okra needs to be transplanted onto beds covered with black plastic mulch, with two staggered rows per bed and plant to plant spacing of 25 to 30 cm apart (Figure 5).

Okra marketable yields at increasing in-row spacing

Figure 5: Okra marketable yields at increasing in-row spacing.

Pest control 

A regular scouting program should be implemented throughout the summer months to detect and identify pests quickly to avoid economic loss. It is important to examine both the upper and lower sides of leaves when looking for pests such as aphids, thrips, leafhoppers, two-spotted spider mites, Japanese beetle, Colorado potato beetle, spotted cucumber beetle, striped cucumber beetle, leafminer, flea beetle, whitefly and tarnished plant bug. Monitoring involves the examination of 10 to 15 plants per hectare in four random locations evenly distributed throughout the field so that plants at the edges and middle of the field are also looked at.

Our research indicates that it is not feasible to grow okra without fumigation on land where high levels of soilborne pathogens such as Verticillium and Fusarium are present. 

For additional information on pest management, consult the Ontario Ministry of Agriculture, Food and Rural Affairs’ Publication 838, Vegetable Crop Protection Guide — 2014-2015. This crop is in Crop Group 8-09: Fruiting Vegetables Group and subgroup 8-09B: Pepper/Eggplant Subgroup and subgroup 8-09C: Non-bell Pepper/Eggplant Subgroup.

For a list of registered pesticides for okra in Canada, click here 

Harvest 

Okra needs to be harvested regularly, as pods quickly become overgrown and therefore unmarketable. Ideally, okra should be harvested every day. For labour planning, it can be assumed that one worker will harvest one acre of okra per day during peak season.

To be marketable, okra must meet these retail specifications: 6.3 to 11.5 cm in length and 12.7 to 25.5 mm in diameter. Marketable pods should also exhibit the following characteristics: a tender consistency, good colouring, an even shape and be free of pest and disease damage. 

Postharvest handling 

After harvest, okra must be immediately cooled to maintain the integrity of the pods. To meet retailers’ specifications, okra should be chilled immediately after harvest to 12oC and be maintained at that temperature through delivery to distribution centres.