WHETHER IT is the cow tongue, red stack or coolie variety, callaloo is a vegetable staple in the traditional Jamaican diet. Originating as a backyard garden crop callaloo has within the last 15 years become an important non-traditional export crop commodity (fresh and processed) earning in excess of US$500,000/annum over the last two years.
The leaves of the cow tongue variety, the most popularly grown in Jamaica, are relatively large and there is a long vegetative period before plants start to seed. The three varieties can be grown throughout the year, however, during the winter months plants growth is less due to the shortened day length.
Callaloo will grow well on most soils as long as there is adequate supply of water, free drainage, rich in organic matter, and with maximum exposure to sunlight. Soil should be ploughed to a depth of 15-20 cm and make into bed. Viable seeds for planting, which can be purchased at farm stores islandwide, are sown in the beds and cover with about 1/4 inch of soil either near the planting site or on some other plot of land. The seedbed may be covered with a mesh material that allows at least 70 per cent of light penetration. This barrier will help to keep major pest from attacking the seedlings.
The best time for transplanting the young, but hardened, callaloo plants is during the cooler times of the day, late evening (preferably) or early morning. Seedlings are replanted into pre-prepared beds into which organic manure is incorporated. The recommended planting distance is 30 cm within rows and 45 cm between rows.
Callaloo responds well to both organic (animal manure) and inorganic fertilisers (commercial fertiliser). Organic fertiliser also includes broken down materials from compost and is more environmentally friendly than the inorganic type. Although a fairly lucrative crop, callaloo is plagued by many leaf eating pests (caterpillars, worms) that adversely affect yield and marketability. The pest, especially caterpillars, can reduce yield by as much as 100 per cent in high infestation, Consequently, farmers rely heavily upon chemical pesticides to reduce crop damage. The frequent use of pesticides has led pest to develop resistant to popular pesticides, which adds to the level of environmental contamination.
CARDI, through the USAID funded Integrated Pest Management Collaborative Research Support Programme (IMP CRSP) project, has made effort to apply basic principles of Integrated Pest Management (IPM) to develop a strategy to reduce pest damage and pesticide inputs and to safely return callaloo to the USDA pre-clearance list.
Fields should be manually weeded to control weed, as weed-killing herbicides will burn the callaloo plant. Note that timely removal of weeds can reduce pest and disease incidence. The crop is ready for harvest 3-4 weeks after transplanting and should be harvest once per week. Shoot should be cut before they develop bark tissue and seeds. Estimated yields range from 642.7- 734.1 kg/hectare (3,500- 4,000 lbs./acre) per week at peak production. Current market price J$2.72/kg ($6 per lb.).
A crop may last 6-8 months depending on the field conditions such as weather and pest and disease pressure. Callaloo should be reaped during the cooler period of the day and harvested stalks should be kept in a shaded area to retard wilting. Fresh cuttings for export are taken to the packinghouse where stalks are trimmed to acceptable stalk length. Trimmed stalks are washed before packing in a solution of 15% table salt and water followed by rinsing in fresh water to effect optimal removal of organisms present.
(Next week pest and disease control of callaloo production)