Commercial cultivation of collard seeds (Sukuma Wiki) is done for their edible, thick, slightly bitter leaves. Collards Seeds (Sukuma Wiki) are offered all year long, but the colder months following the first frost are when they are sweeter and more nourishing. The leaves are harvested before they reach their maximum size since they are thicker and require a different cooking method than the young leaves. The flavor is unaffected by age. The cultivar also affects taste and texture; in Brazil and Portugal, the couve manteiga and couve tronchuda are particularly prized.
Ectoparasites that can harm collard include the awl nematode Dolichodorus spp. and the sting nematode Belonolaimus gracilis. Stubby or coarse roots with dark tips are examples of root symptoms. Stunted development is one of the signs of a shoot, premature chlorosis, and wilting. Belonolaimus longicaudatus, a different species of sting worm, is a pest of collards in Georgia and North Carolina. B. longicaudatus kills transplants and seedlings. On plants that are vulnerable, as few as three nematodes per 100g of soil after transplanting can result in considerable yield losses. Their prevalence is highest in sandy soils.
The taproot tips of collards are where the stubby root nematodes Trichodorus and Paratrichodorus connect and feed. A “stubby root” is the result of an injury that limits correct root elongation, which causes tight mats that may appear bloated.
Collards are infested by a number of species of the root-knot nematode Meloidogyne spp. These include M. arenaria, M. javanica, and M. incognita. Juveniles in their second stage attack the plant and settle in the roots. Although, Compared to other cruciferous plants, infection appears to occur at lower populations. Deformation (galls) and damage, which obstruct proper water and nutrient intake, are examples of root symptoms. This may eventually cause the shoots to stunt, wilt, and develop chlorosis.