The analysis of yield-density relationships in binary mixtures using inverse polynomials

SUMMARY The reciprocal relationship commonly used in the analysis of plant yield-density relationships in monoculture is extended to allow a similar treatment of binary mixtures, using the model: w –1 a = A a × B aa p a × B ab p b where w a is the plant weight of component a in mixture with component b , and p a and p b are the plant densities of a and b respectively. The model gives a good fit to fresh weights taken from a glasshouse experiment involving monocultures and mixtures of red clover ( T. pratense L.) and Italian ryegrass ( L. multiflorum L.) in different proportions, all grown at a range of plant densities. The interpretive and predictive uses of the model are discussed.