Varietal colour of Lolium perenne L turfgrass and its interaction with environmental conditions

A field experiment was conducted to examine colour changes in a range of turfgrass varieties and selections of Lolium perenne. Colour was recorded, in terms of Hue Angle (H°) and b* (tonal modification) parameters, at fourteen monthly intervals and at two contrasting fertiliser regimes. There were significant overall differences between the varieties for both colour parameters. There were also significant variety × fertiliser and variety × time interactions for both parameters. The interactions were further investigated by linear regression analysis. The selections were greener overall than the varieties. The higher regression coefficient of the varieties except for 'Aberystwyth S23' indicated that they were able to produce high H° under presumably favourable conditions, but under less favourable conditions, H° was reduced more than with the selections. 'Aberystwyth S23', despite having the lowest overall H° score maintained this level under less favourable conditions as indicated by its low regression coefficient. For b* scores, the selections were darker and duller than the varieties overall and were also able to maintain this colour better under the conditions encountered as indicated by the lower regression coefficients. The significance of these findings for breeding and selection programmes, varietal assessment and the end-user are discussed.