Spatial and Temporal Deployment of Cultivars Effects on Rice Cultivar Mixtures

Field studies were conducted in two cropping seasons at Calabar, Southeastern Nigeria to evaluate the effect of relative time of introducing two lowland rice cultivars and spatial arrangement on the productivity of components in the mixture. Treatments comprised all possible factorial combinations of two spatial arrangements (between or alternate rows, and within rows or alternate hills) and five times of introduction (transplanting FARO 52 two weeks before - ,one week before -, same day as -, one week after and two weeks after - Muduga) laid out in randomized complete block (RCB) design with three replications. Results showed that introducing Muduga two weeks after FARO 52 reduced plant lodging percent of the cultivar by 35.2, 74.3, 100.4, 175.7% compared to when the cultivar was introduced one week after -, same- day as -, one week before -, and two weeks before - FARO 15, respectively. Grain yield of both cultivars were significantly higher (p=0.05) when the introduction of Muduga was delayed due to the favorable effect on lodging. All times of introduction studied except introducing FARO 15 two weeks after Muduga gave land equivalent ratio (LER) values greater than unity suggesting that a higher productivity per unit area was achieved by interplanting these cultivars than growing either of them separately. The highest LER values were obtained with the introduction of FARO 15 any time before Muduga. Spatial arrangement did not seem to influence the productivity of the system.