REGROWTH, MORPHOLOGY AND PERSISTENCE OF GRASSLANDS PUNA CHICORY (CICHORIUM-INTYBUS L) IN RESPONSE TO GRAZING FREQUENCY AND INTENSITY

Effects of different grazing frequencies and intensities on herbage pr oduction (on both a unit pasture and individual plant basis) and on pe rsistence of chicory (Cichorium intybus L. cv. Grasslands Puna) were s tudied at Palmerston North, New Zealand (latitude 40 degrees 23'S) fro m November 1994 to November 1995. Three experiments were conducted on the same chicory stand, sown on 12 May 1994. The main grazing experime nt had two grazing intensities, hard-lax grazing (50- to 100-mm stem s tubble to mid-January, and thereafter 100- to 150-mm stem stubble) and lax grazing (100- to 150-mm stem stubble), and three grazing frequenc ies (1-, 2- or 4-week intervals). A subsidiary plant survival experime nt compared the survival of 120 marked plants in ungrazed and grazed t reatments. A late autumn grazing experiment examined the effects on. p lant persistence in the following spring. The greatest herbage mass (l eaf + stem) resulted from the 4-week grazing frequency [9640 +/- 874 k g dry matter (DM) ha(-1)], in which stem mass was reasonably low (1270 +/- 410 kg DM ha(-1)), but was significantly higher in the 4-week gra zing frequency than 1- and 2-week grazing frequencies (P < 0.01). Graz ing intensity had no significant effect except on the average stem mas s of individual plants when the hard-lax intensity gave a lower stem m ass (P < 0.01). There were no interactions between grazing frequency a nd intensity in herbage mass. Plant density declined by 35% over the g rowing season with the decline unaffected by grazing intensity or freq uency during the season. Grazing in late autumn resulted in approximat ely 27% less plants in the following spring. It was concluded that gra zing management through the growing season cannot be used to improve p ersistence without compromising leaf growth rate, but that avoidance o f grazing in late autumn will improve the persistence of chicory.