Effect of Disease on Tomato Production in Soilless Cultivation in the Korhogo Area, Northern Côte d’Ivoire

Despite its advantages, soilless cultivation faces various biotic and abiotic constraints that can reduce production. This study aimed to identify the diseases affecting soilless tomatoes and evaluate their effects on the production. The UC 82 and the EAGLE F1 varieties were used as plant material. The methodology consisted of weekly observations in five squares of 15 m2 per greenhouse. Each square contained six tomato plants. From the observations and data collected, diseases were identified, incidence, severity and yield were calculated according to appropriate formulas and the economic analysis was performed. The results revealed that the blossom-end rot, alternaria, downy mildew, anthracnose and fruit cracking were present in the UC 82 variety. Alternaria, with an incidence of 19.69 % and a severity of 7.35 %, was the most severe disease. However, the EAGLE F1 variety presented only one disease, the fruit cracking, with an incidence and severity of 16.89 and 2.36 % respectively. The diseases led to a significant decrease in yield for both varieties (EAGLE F1: 190 t/ha; UC 82: 88.8 t/ha). This resulted in a loss of 76.18 and 31.06 % of the investment for the UC 82 and the EAGLE F1 varieties respectively. In conclusion, the diseases have been a major obstacle to soilless tomato production in northern of Côte d'Ivoire.