A f i e l d experiment was conducted at Saminaka and Samaru in 1983 with the aim of determining the effects of plant population and cropping pattern on the yield and yield components of maize and sorghum in mixture. An attempt was aisn made to determine the optimum plant population and cropping pattern for the mixture. A f a c t o r i a l experiment was laid out in a randomized complete block design with four r e p l i c a t i o n s . Combination of two plant populations (44,444 and 66,666 plants ha- 1 ) and six cropping patterns (2:1 and 1:2 of maize: sorghum mixture at alternate row and within row arrangement together with sole maize ana sorghum) made up the treatments. Increasing plant population of maize in the mixture from 44,444 to 66,666 plants ha- 1 ) increased the grain yield at Samaru but not at Samina.ka. The 2:1 proportion of maize:sorghum at a l t e r n a t e and mixed within row gave better grain yield of maize than the 1:2 proportion, but inferior to the sole maize at both locations. These observations were supported by data on light interception. At both. Samaru and Saminaka, plant population levels and cropping pattern failed to affect the grain yield of sorghum. There was an average mixing advantage of 20% for the 2:1 and 1:2 proportions at Samaru while at Saminaka, the mixing advantage were 25% and 30% for the a l t e r n a t e and mixed row respectively. The land equivalent r a t i o (LER) gave a similar r e s u l t s with an average of 1.37 and 1.07 for the 2:1 and 1:2 proportions at both sites. At Samaru, all cropping patterns gave higher grain yield at higher plant populations except for a small decline in the 112 mixed row while at Saminaka, three of the mixed crops responded positively to plant populations whereas “both sole crops responded negatively. The alternate row had higher LER at Samaru while the mixed row arrangement had higher LER at Saminaka. It is therefore obvious from this work that the optimum arrangement for sorghum:maize mixture is conclusive. The 2:1 proportions (maize:sorghum) performed better than the 1:2 proportions at both locations.
THE EFFECT OF PLANT POPULATION AND PLANT ARRANGEMENT OF THE PERFORMANCE OF MAIZE (Zea mays L.) AND SORGHUM (Sorghum b i c o l or L. Moench) IN MIXED CROPS