EFFECT OF FERTILIZER ON INCIDENCE AND SEVERITY OF CERCOSPORA LEAF SPOT AND YIELD-RELATED TRAITS OF KENAF (HIBISCUS CANNABINUS L.)

Abstract

Kenaf (Hibiscus cannabinus L.) is a herbaceous dicotyledonous with many industrial applications, however, its production is affected by several factors including soil nutrients and diseases. The use of fertilizer type and rate to minimize disease incidence is important. The experiment was carried out to evaluate the effect of organic and inorganic fertilizers on the incidence and severity of Cercospora leaf spot as well as yield-related traits of kenaf. Ifeken DI 400 was planted at the spacing of 0.2 m within the row and 0.5 m apart and commercially produced organic and inorganic fertiliser was applied each at 0, 70, 100, 130 and 170 kg/ha. The experiment was laid out in a randomized complete block design with three replicates. Data were collected on plant height, core yield bast yield, total yield, disease incidence and disease severity. Phytochemical analysis of the soil samples and fertilisers was carried out. Data collected were subjected to analysis of variance. means were separated using Duncan’s multiple-range test. The highest core, bast and total yield of 133.97 kg/ha, 219.19 kg/ha and 353.14 kg/ha respectively were obtained from kenaf plants treated with 170kg/ha of organic fertiliser and plant height of 214.64 cm. The highest incidence of Cercospora leaf spot was observed with kenaf plants treated with 130kg/ha of NPK, while there was no correlation between the disease incidence and inorganic fertilizer. In conclusion, a higher rate of NPK above 130kg/ha only increased the disease incidence but did not increase the yield of the crop.