The effect of harvest date on the yield and mineral content of Phalaris arundinacea L. (reed canary grass) genotypes screened for their potential as energy crops in southern England

The effect of harvest date on dry matter production per hectare and moisture content of 13 genotypes of Phalaris arundinacea (reed canary grass) was studied between 1995 and 1998 and N, P and K concentration in biomass was measured in 1998. There were two winter harvests, the first at crop senescence and the second after a subsequent delay of several weeks which varied each year. Average dry matter production was higher at the first (conventional) harvest than at the delayed harvest except in 1996. Each year there were differences in yield between genotypes and some differences were significant. Delayed harvest reduced yield by an average of 24% in 1997 and 23% in 1998 when losses resulted from 48% loss of leaf and 16% of stem matter. Delayed harvest decreased moisture content by 50% in 1997 and 52% in 1998 but it was 49% higher in 1996. In 1998, delayed harvest did not reduce N concentration in all genotypes and the reduction of P was variable, but K concentration was reduced by an average of 54%. Results indicate the suitability of reed canary grass as a biofuel, and variability between genotypes offers potential for crop improvement through selection and breeding. (c) 2006 Society of Chemical Industry