Regrowth, morphology and persistence of Grasslands Puna chicory (Cichorium intybus L.) in response to grazing frequency and intensity

Abstract

Effects of different grazing frequencies and intensities on herbage production (on both a unit pasture and individual plant basis) and on persistence of chicory (Cichorium intybus L. cv. Grasslands Puna) were studied at Palmerston North, New Zealand (latitude 40°23′S) from November 1994 to November 1995. Three experiments were conducted on the same chicory stand, sown on 12 May 1994. The main grazing experiment had two grazing intensities, hard‐lax grazing (50‐ to 100‐mm stem stubble to mid‐January, and thereafter 100‐ to 150‐mm stem stubble) and lax grazing (100‐ to 150‐mm stem stubble), and three grazing frequencies (1‐, 2‐ or 4‐week intervals). A subsidiary plant survival experiment compared the survival of 120 marked plants in ungrazed and grazed treatments. A late autumn grazing experiment examined the effects on plant persistence in the following spring. The greatest herbage mass (leaf + stem) resulted from the 4‐week grazing frequency [9640 ± 874 kg 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 grazing frequency than 1‐ and 2‐week grazing frequencies (P < 0·01). Grazing intensity had no significant effect except on the average stem mass of individual plants when the hard‐lax intensity gave a lower stem mass (P < 0·01). There were no interactions between grazing frequency and intensity in herbage mass. Plant density declined by 35% over the growing season with the decline unaffected by grazing intensity or frequency during the season. Grazing in late autumn resulted in approximately 27% less plants the following spring. It was concluded that grazing management through the growing season cannot be used to improve persistence without compromising leaf growth rate, but that avoidance of grazing late autumn will improve the persistence of chicory.