Effect of different doses of NPK fertilizer on the infection coefficient of rice (Orysa sativa L.) Blast in Ndop, North West of Cameroon
The developpement of fungi diseases such as Rice blast which cause important yield losses in rice cultivation in Cameroon is favorite by a variation of doses in minerale fertilisation. Since those elements facilitate the infection process and the development of pathogens. As part of the solutions to this constraint, a field trial was conducted using NPK fertilizer at three different doses, i.e., 180 kg/ ha ; 200kg/ha ; 220 kg/ha plus a control (0 kg/ha). Four rice varieties were used : NERICA 3 and NERICA 7 as upland rice varieties while NERICA 36 and NERICA 42 as lowland rice varieties. To evaluate the influence of the different doses of fertilizers (NPK), a randomised complete block design was used. Disease parameters like incidence and severity of rice blast were evaluated at all the growth stages. Results obtained revealed that disease incidence and severity of rice blast during the vegetative growth of the different varieties of rice, was more significant on the control compared to the other treatments and lowland rice varieties were more infected than upland rice. Fertilizer N-P-K (20-10-10) at the dose 200 kg/ha makes the plant less susceptible to the blast at all its growth phases. Thus, the use of fertilizers at the proper doses is necessary for fighting against rice blast.
Keywords : Rice blast, NPK Fertilizer, rice varieties