Establishment and grazing management of 'Grasslands Puna' chicory (Cichorium intybus L.)

Abstract

'Grasslands Puna' chicory was bred for dryland farming. Chicory is a pasture herb which is dormant during winter but actively grows in spring, summer and autumn. A wide range of sowing rates have been reported for pure and mixed stands but establishment recommendations have not been clearly defined. Chicory will not survive frequent grazing. Reported results indicate that chicory should be grazed with a long spelling time and lax defoliation, but recent work has shown that hard grazing in spring is required to control primary stem growth so that maximum leaf production can be achieved.

Three experiments were carried out to find out more about establishment and grazing management of chicory. The objectives were (a) to determine a suitable chicory sowing rate for either pure swards or pasture mixtures with clovers or winter active grasses and (b) to investigate the responses of chicory to two grazing frequencies and two grazing intensities combined in a 2² factorial design to give four grazing treatments.

Herbage mass, botanical components, plant population and taproot weights were measured in two chicory sowing rate field experiments. Plots measured 1.5 m and 2.5 m (3.75 m²). Companion species were 'Grasslands Kopu' white clover, 'Grasslands Pawera' red clover, 'Grasslands Matua' prairie grass and ‘Grasslands Maru' phalaris. In experiment A there were 27 treatments of 8 single species stands (4 pure chicory sowing rates - 0.75, 1.5, 3 or 6 kg/ha - and each companion species), 10 binary mixtures, and 8 complex mixtures. In experiment 8 treatments were binary mixtures of the four chicory sowing rates and prairie grass or phalaris. Sampling dates for the first three characteristics were 24-28 February, 15-20 May, 16-17 August and 15-19 November 1993. Taproots were dug out only from pure chicory plots on 16 December 1993.

Pure chicory production was greatest at high sowing rates. From four harvests, total yields from chicory sown alone ranged from 920 g DM m⁻² yr⁻¹ at 0.75 kg seed/ha to 1480 g DM m⁻² yr⁻¹ at 3 kg/ha. When mixed with 'Pawera', which yielded from 140 to 380 g DM m⁻² yr⁻¹, chicory yielded from 780 to 1270 g DM m⁻² yr⁻¹. Chicory yielded 830 to 1280 g DM m⁻² when mixed with 'Kopu' (45 to 250 g DM m⁻² yr⁻¹. In general dry matter yields of companion species and weeds decreased as chicory populations increased. The large seeded species, 'Matua' prairie grass and 'Pawera' red clover, were more competitive with chicory than the slower establishing small seeded species, 'Maru' phalaris and 'Kopu' white clover. Final population after one year increased from 50 plants m⁻² at 0.75 kg/ha to 135 plants m⁻² at 6 kg/ha. Individual taproots weighed four times more at 0.75 kg than at 6 kg/ha. Taproot yield was 350 g DM m⁻² at low sowing rates and 270 and 260 g DM m⁻² at 3 and 6 kg/ha, respectively. Mean crown diameter declined from 26 mm at 0.75 down to 18 mm at 6 kg/ha.

In the grazing trial the four grazing treatments were replicated five times. Grazing plots were 480 or 890 m². Replicates of the grazing treatments were sequentially grazed by ewe hoggets (35-50 kg live weight). There were ten grazing cycles starting from 25 January 1993 and finishing in February 26 1994. Pre- and post- herbage mass, plant components and plant population were measured. Taproot and crown measurements were recorded in March and July 1993 and March 1994. Volunteer white clover appeared in early spring and it was also measured.

The hard grazing treatments produced more high quality feed (leaf) than the lax grazing treatments. Total pre-grazing dry matter yields of chicory were 1620, 2840, 2080 and 3045 g DM m⁻² year⁻¹ under hard frequent (HF), lax frequent (LF), hard infrequent (HI), and lax infrequent (LI), respectively. From the latter leaf yields represented 90 and 37% in the HF and LI treatments, respectively. In March 1994 taproots weighed less under hard or frequent grazing than under lax or infrequent grazing. Mean crown diameter was significantly greater (18.9 mm, P< 0.000) under infrequent than under frequent grazing (15.9 mm). Chicory crown diameter was also smaller under hard grazing (16.5 mm, P< 0.003) than lax grazing (18.2 mm). Number of crown buds per taproot varied (P< 0.044) from 2.5 to 2.2 under frequent and infrequent grazing, respectively. When chicory was heavily grazed crown buds numbered 3.2 but reduced to 1.5 under lax grazing. Volunteer white clover was most productive in the laxly grazed plots and appeared to reduce chicory population and yields. Sclerotinia spp fungus also appeared to cause more chicory plant death in laxly grazed plots.

It was concluded that pure chicory should be sown in a range of 1.5-3 kg seed/ha. Chicory sowing rates lower than 1.5 kg/ha are recommended for binary or complex mixture with clovers or winter active grasses. Some grazing strategies are discussed regarding chicory as a versatile pasture herb which can tolerate different grazing managements so long as the plant is spelled between grazings. Hard grazing in spring is recommended to control primary reproductive stems. Longer spelling in autumn may be important for maintenance of taproot reserves.