COLLARD: Its Role in Conservation Planning
Rani G. Kumar, Girish K. Panicker*, and Franklin Chukwuma Collards (Brassica oleracea L. Acephala Group) are leafy, cruciferous, perennial vegetables with dark green color and sturdy, smoky taste. They belong to the non-head forming Brassica/cabbage family. The frost-hardy collard originated in Asia Minor and Mediterranean. This ancient vegetable used to be a part of Greco-Roman diet and botanical historians believe that the collard plant has changed rarely in shape for the last two millenniums. Occasionally called collard greens, the bitter, waxy vegetable was brought to prominence in the United States by the Africans. Its nutritious leaves are cooked customarily as greens in the southern American dwelling. PURPOSES
To conserve soil and water through the use of vegetation To maintain and/or to improve soil availability, quality, and soil nutrients To suppress weeds, reduce insect pests and diseases, and increase crop yield To improve soil tilth, soil organic matter, and soil structure
Planting: Collards are started from transplants or seeds sown directly in the garden. A pH of 6.0 to 6.5 and 450 F temperature is needed for the seeds to sprout and for healthy growth. They bear more heat and cold (withstands temperatures as low as 150 F) than nearly all other vegetables. Collards require above average moisture, plenty of sunlight and grow on diverse soils. Maximum yields are generated by fertile and heavier loamy soils. Adding organic matter to clay or light sand will bring good result. In the southern regions of the US, collards are planted in the fall and the spring. In the North, two crops
2 are possible by planting in early spring and for a second time in July or August. This deep rooted plant stretches to 2’ or longer and so the soil must be cultivated as deep as possible. Fall planted and early winter harvested collards are estimated top quality. Ensure to mix composted plant or animal manure with the soil 2 or 3 weeks before planting to boost growth. To increase their darkish green leaf color, scatter 1 cup of nitrogen fertilizer beside the collard plants for each 30 feet of row and combine it well with soil, fish emulsion or manure tea and water. Carrots are good companion plants for collards. With proper care, collard greens are obtainable all year round. Spacing: Dig the soil at least 10 inches. A 3 inch layer of compost is adequate. Clear the soil of rocks and large sticks. Scatter garden fertilizers such as 10-20-10 about 1 cup for each 10 feet of row. Set the plants in the soil deep, with only 1/3 of the plant sticking above ground. Work the soil into ridges 6 to 8 inches high and at least 24-36 inches apart. This brings the fertilizer underneath the row and is easily reachable to the plant roots. The ridges also allow water to drain away from the plant roots. Harvesting: Collards are ready for harvest by 6-8 weeks, when the leaves reach 10 - 12 inches tall. Either the leaves are “cropped� leaving the bud to grow new leaves or the entire plant is harvested at one cutting. Usually, the lower leaves of collards are harvested, allowing the plant to keep growing. With proper care, collards can be harvested in all 12 months of the year, especially in warmer regions. The leaves stay tender and edible for several days even after they reach maturity. Collard leaves taste sweeter after a light frost. Crop rotation: The advantageous system of crop rotation refers to systematically planting different vegetables within the same land, from year to year. Annually rotating vegetables help minimize infestations, soil borne disease problems, and maintains soil fertility. Fungi, bacteria, and nematodes that cause root and foliar diseases persist in soil or crop debris in the soil. These pathogens amass to damaging levels with repeated cropping of crucifer crops. Crop rotation is very effective where crops in the crucifer family are avoided for at least two years. The choice of crop rotation depends on the nature of the soil. To raise collards successfully, rotations with corn, grain sorghum, or another summer grass crop are recommended. Mulching: This is the established and long-lasting horticultural practice of placing protective materials over the soil exterior. It serves several purposes in agricultural production including weed growth reduction, conservation of soil moisture and nutrients, soil temperature regulation, soil erosion prevention, and decrease of water splashing on plants, which minimizes the spread of diseases. Mulches should not be applied ahead of time in the spring because this process delays soil warming. Wait until the soil is 65 o F and make a depth of 4 inches before applying mulches. Guarantee to keep all mulches 2 to 3 inches away from the stems of plants. There are inorganic and organic mulches. Examples of organic mulch materials include compost, partially decomposed hey, straw,
3 wood chips, sawdust, lawn clippings or leaves. Plastic is the only inorganic mulch used in vegetable gardens. Weed Control: Avoid deep cultivation and use shallow method to minimize weeds. To expressively ward off weed growth, utilize speedy growing and broad leaved varieties with near spacing. Some weeds in and around fields may shelter viruses and so the planting season and the production scheme must be chosen vigilantly to handle the type and range of weed problems. Herbicides are available for use on collards and are generally recommended. Common weeds in the crucifer family, such as swine cress and pepper weed, can conceal and shelter black rot bacteria. Timely weed control minimizes chances of disease carryover. Also, good irrigation method combined with mulching diminishes weeds. To destroy pests like aphids, cabbageworms, mole crickets, whiteflies, flea beetles and root maggots, place floating row covers over the transplants or seedbed. Planting catnip alongside collards reduces flee-beetle damage on the collards. Residue Management: Since many pathogens survive in and on crop debris, crop residue should be incorporated by disking or plowing soon after harvest to promote rapid decomposition. Deep plowing prior to planting also is beneficial for burying crop and weed remains, which may harbor pathogens. Crop residue management has been established as a valuable technology for reducing erosion and improving run-off water quality from agricultural lands. Surface residue management is the most promising and practical erosion control practice in use today. Residue inputs subsequently modify soil properties important to soil quality and crop production. Collards provide a moderate canopy with more than 50% vegetation after 60 days of planting, but the maximum fresh plant residue cover after harvesting and disking recorded is only 20%. The yield ranges from 30,000 to 40,000 lbs per acre. Total fresh residue mass ranges from 7,000 to 8,000 lbs, which is equal to 1700-1750 lbs of dry residue. Collard residue contains 38% carbon (C) and 1.89% nitrogen (N) and at this rate, the crop returns 645 to 665 lbs of carbon and 32 to 33 lbs of nitrogen per acre to the soil.
_______________________________________________________________________________________________ Published by Cooperative Extension, Department of Agriculture, Alcorn State University, Mississippi, in collaboration with the USDA/NRCS. Alcorn State University is deeply grateful to the USDA/NRCS for providing funds for this publication. Corresponding author*. Alcorn State University does not discriminate on the basis of race, color, religion, national origin, sex, age or handicap