Influence of fertilizers on incidence and severity of early blight and late blight potato diseases under field condition

The potato (Solanum tuberosum) production in the Far North Region, Cameroon is confronted with, diseases and pests. To improve the production of this plant, a study was carried out in Mouvou and Gouria to evaluate the impact of fertilizers on the development of late blight and early blight diseases of this plant. The experimental design used was a completely randomized block with 4 treatments: Mycorrhizae (MYC), NPK (20-10-10) chemical fertilizers, chicken droppings (CD) and a control (T). The plant material used was a local variety of potato (Dosa). Disease incidence and severity and rainfall were evaluated. Area Under Disease Progress Curve was calculated. At 60 DAS, mean incidences recorded for fertilizers were 5.7, 3.6, 1.8 and 0.8 % respectively for control, MYC, NPK and CD. In general, early blight severity decreased from 22.1% at 45 DAS to 0.3 % at 60 DAS. The highest AUDPC value of late blight at Mouvou site was observed in NPK treatment while potato in CD treatment had the lowest. The lowest AUDPC value of early blight was observed in CD treatment at both sites. AUDSIPC value for late blight was significantly higher in NPK treatment in both sites. The highest value of AUDPSIC of early blight was recorded in MYC treatment, 45 DAS in both sites. The average rainfall was higher in the Gouria site (716.5mm) than in Mouvou site (679 mm). The CD treatment can be recommended to the farmers for the phytosanitary protection of potatoes.