Economic assessment of tillage systems and weed control methods in maize (Zea mays L.) cultivation in southwestern Nigeria

This study was conducted to appraise the economics of different land preparation systems and weed management options in maize cultivation in three ecological zones (Ikenne, Ibadan and Ilorin) of southwestern Nigeria. Four tillage systems as main treatments and six weed control methods as sub-treatments were accommodated in a split-block arrangement of randomized complete block design with three replications. The main treatments were no-tillage (NT), ploughing and harrowing (PH), ploughing twice (PP), ploughing twice and harrowing (PPH) while the sub-treatments were atrazine plus metolachlor (Primextra) at 2.5 and 3.5 kg a.i. ha-1, atrazine plus pendimethalin at 1.25 + 0.83 and 1.75 + 1.16 kg a.i. ha-1, handweeded and unweeded checks. Net benefits achieved from no-tillage system were lower than that of mechanical tillage in all the locations. Greater net returns were obtained from PPH and PH treatments where handweeding or chemical weeding was used. Increased herbicide rate was not economical under the mechanical tillage systems. Any of the mechanical tillage methods can be employed in the three locations. Atrazine plus metolachlor or atrazine plus pendimethalin mixtures are profitable for maize production in Ikenne and Ibadan while the latter is profitable in Ilorin. Keywords: Tillage; weed control; economic; herbicides; maizeMoor Journal of Agricultural Research Vol. 7 (1&2) 2006 pp. 15-20