Evaluation of Turnip (Brassica napus) Production on Different Substrates in Côte d’Ivoire
Soumahoro Brahima André
*
Département des Sciences et Technologie, Section Sciences de le Vie et de le Terre (SVT), Ecole Normale Supérieure d’Abidjan, 08 BP 10 Abidjan 08, Côte d’Ivoire.
Sanogo Souleymane
Université Félix Houphouët-Boigny; Abidjan, Cocody; 22 BP 582 Abidjan 22, Côte d'Ivoire and Centre d'Excellence Africain sur le Changement Climatique, la Biodiversité et l'Agriculture Durable (CEA-CCBAD) de l'Université Félix Houphouët-Boigny (UFHB), 22 BP 582 Abidjan 22, Côte d'Ivoire.
Ouattara Laddy
Laboratoire de Phytotechnie et Amélioration des Plantes, UFR Sciences de la Nature, Université Nangui Abrogoua, Abidjan, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Koné Tchoa
Laboratoire de Biologie et Amélioration des Productions Végétales, UFR Sciences de la Nature, Université Nangui Abrogoua, Abidjan, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Koné Mongomaké
Laboratoire de Biologie et Amélioration des Productions Végétales, UFR Sciences de la Nature, Université Nangui Abrogoua, Abidjan, 02 BP 801 Abidjan 02, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Turnip (Brassica napus) production in Côte d’Ivoire is constrained by limited cultivable land, while reliance on chemical fertilisers raises environmental concerns. This study evaluated locally available soil–compost substrates for turnip production under soilless conditions at the École Normale Supérieure d’Abidjan from June to December 2025. Five substrate treatments were assessed: 100% soil (S1), 100% compost (S2), 75% compost + 25% soil (S3), 50% compost + 50% soil (S4), and 25% compost + 75% soil (S5). Seeds of the hybrid turnip variety MAXIMUS were sown in pots arranged under a shade structure, with watering applied as required. Germination rate, leaf production, plant height, and yield were evaluated. Germination was most rapid on S4, while substrates containing compost generally supported greater vegetative growth than the soil-only control. The highest number of leaves was recorded on S4 and S5. Plant height was greatest on the 100% compost substrate. Yield was highest on S4, reaching 1,820 kg/ha, whereas the soil-only control produced the lowest yield at 383 kg/ha. Overall, the 50% compost + 50% soil mixture provided the most favourable balance between vegetative development and yield. These findings support the use of a locally formulated soil–compost substrate for turnip production under the conditions of this experiment.
Keywords: Brassica napus, turnip, soilless cultivation, compost, soil–compost substrate, growing medium, germination, vegetative growth, yield