INCIDENCES AND SEVERITY OF WEED SPECIES IN MAIZE/COWPEA INTERCROP AT SAMARU NORTHERN GUINEA SAVANNA OF NIGERIA

Experiments were conducted on maize/cowpea intercrop at the Research Farm of the Institute for Agricultural Research, Ahmadu Bello University Zaria, (110 111 N 380 E) in the Northern Guinea Savanna of Nigeria. Samples of weeds were collected to assess the occurrence and severity of noxious weeds and other broad leaved weeds. Eragrotis ciliaris, Eleusineindica and Rottboelliaco chinchinesis were widely spread in the three years of the study (2010, 2011 and 2012). The incidences were generally higher in 2012 in all cases. Striga gesneroides, Alectra vogelii and Cuscuta australis were found in all the blocks and they increased on yearly bases. Generally, across board, weed infestation increased on yearly bases.