Demand-Driven Technologies for Sustainable Maize ... - IITA

173Table 1. Effects of sole and intercropping on plant population, Strigainfestation and incidence, crop damage severity and grain yieldof maize in two villages in northern Nigeria (2001).CroppingsystemsSole maizeMaizecowpeaintercropsplit-applied at 3 and 6 WAS. Fertilizer was applied to the soybean andcowpea at the rate of 20 kg N ha -1 , 40 kg P 2O 5ha -1 , and 20 kg K 2Oha -1 at 2 WAS using NPK (15:15:15) and single superphosphate. Thecowpea crop was sprayed with cyper-plus at the rate of 1 l ha -1 at fl owerbud initiation while benlate was applied at 0.4 kg ha -1 during podding tocontrol diseases and insect pests. At the end of each year, the cowpearesidue was fed to livestock while the maize stalks were used either forfencing or fuel. However, withered soybean leaves were allowed to rotand were plowed back to the soil to improve soil fertility.Data collected included maize stand count, Striga shoot count(infestation), number of maize plants infested (incidence), hostdamage severity on a scale of 1–9 (where 1=healthy plants and 9= completely dead plants), and grain yield of maize. The data weresubjected to analysis of variance and treatment means were separatedusing Duncan Multiple Range Test (DMRT). Data on yields of soybeanand cowpea are not reported in this paper.ResultsMaizeplants ha -1at 12 WAS21,013a**17,371bStriganumberha -1 at12 WAS1158a433bNumber ofmaize plantsinfested ha -1at 12 WAS414a295bCropdamageseverity*2.33a2.58bGrain yield(kg ha -1 )810.42a613.54aWAS = weeks after sowing.* = Crop damage severity using a scale of 1 - 9, where 1 = healthy plants and9 = completely dead plants.**Means followed by the same letter(s) within a column are not signifi cantly differentat the 0.05 level of probability (DMRT).Sole and intercropping effects on Striga and maize in the firstyear (2001)In 2001, the sole-cropped and intercropped maize exhibited similarlow levels of crop damage severity. The sole maize had better plantestablishment than the intercropped maize although these wereplanted at the same density. Striga infestation and incidence werelower when maize was intercropped with cowpea than when plantedsole. However, maize grain yield was 32% higher when planted solethan when intercropped with cowpea (Table 1).