Resumen
Leaf spots of groundnut caused by Cercospora spp is one of the major economic production constraint militating against groundnut production in Nigeria. Field experiments were conducted during the 2011 and 2012 seasons at the Teaching and Research Farm of the Federal University of Agriculture, Makurdi Nigeria to assess the effect of sowing dates on the incidence of Cercospora leaf spot of groundnut The 2 x 4 x 3 factorial (2 groundnut varieties/ 4 sowing dates/ 3 replications) experiment was laid out in a Randomized Complete Block Design (RCBD) and replicated three times. Results indicated no significant effect of Cercoscora leaf spot on the two varieties in 2011 but in Ex-Dakar recorded a significantly (P < 0.05) higher leaf spot incidence compared Borno-Red variety. Sowing groundnut seeds in 14th June to 29th June recorded significantly higher (P < 0.0) leaf spot disease incidence compared with sowing groundnut seeds in May. Ex-Dakar variety recorded higher leaf defoliation compared with Borno-Red variety in 2012 and 2012 seasons. Results indicated that Borno-Red had a significantly (P < 0. 05) higher 100 seed weight in 2011, while Ex-Dakar recorded higher 100 seed weight in 2012. The results has proved that early sowing of groundnut in May can be employed as alternative strategy for the management of leaf spot disease of groundnut in Makurdi, NigeriaKey word: Groundnut, disease incidence, sowing date, leaf defoliation, leaf spot.