Summary
Chicory (Cichorium intybus L.) is a perennial herb and member of the family Asteraceae. It is considered native to the mediterranean region. thongh it had spread throughout much of Europe and into central Asia before being used by man. The release of the New Zealand cultivar Puna in 1984 spurred considerable interest in using this species as a pasture herb. Initial results suggested it was capable of high rates of forage and livestock production. Early work in Australia supported that view and suggested chicory was also productive under dry seasonal conditions. Chicory could fill a very useful role in providing greater quantities of quality forage over summer when most other species have limited growth. The aim of this project was to develop the agronomic practices to use chicory to fill the summer feed gap in the high rainfall zone of temperate Australia.
The specific objectives were to:
i) Compare chicory and lucerne for elite lamb production.
ii) Determine the grazing management practices for chicory pastures to ensure optimal persistence and productivity.
iii) Determine the appropriate mixtures for chicory pastures for optimal productivity and weed management.
iv) Determine suitable herbicides for early post-emergent use, optimal sowing rate, response to nitrogen fertiliser and other management factors to complete a management package for chicory.
The ability of chicory to finish elite lambs was compared with lucerne in an experiment at Cowra over two years. Four groups of lambs were used. Lamb growth rates of 200-300 g d-l were recorded. Lambs grew as well or better on chicory as lucerne and most met market specifications. The differences between pasture species were greater with cryptorchid than ewe lambs. Semi-winter active lucerne cultivars though can have a longer growing season. There could be problems with feed standards as chicory samples showed lower (apparent) values for ME, protein and digestibility than were measured for lucerne in contrast to that expected from the animal performance data.
There was evidence that intake rates were initially higher on chicory than lucerne, but the average intake rate for a group of lambs was similar for both species. The role of differences in mineral content is unknown. The use of chicory for lamb production will depend upon the region involved and the pasture alternatives available. From the Cowra study we concluded that where lucerne can be grown well, it is still one of the better options for finishing lambs, as chicory offered no extra production. However, where lucerne starts to become marginal, yet soils still have some depth and rainfall is above 600 mm, chicory is a very viable option. We suspect from earlier work that chicory will retain green leaf longer during dry summers than lucerne, but we have not been able to collect adequate data on that during this project. Chicory does require some summer rainfall and, or irrigation, plus moderate moisture stored at depth to be productive. Chicory management and adaptability is likely to be more flexible than is the case for lucerne. Special purpose chicory pastures would be better for finishing lambs than most perennial grass based pastures in central NSW as they would produce larger quantities of nutritious green leaf ovr summer. Chicory would fit within those zones already defined as suitable for elite lamb production over summer.
A long-term experiment investigated the grazing management of chicory; Treatments ranged from continuous grazing to combinations of short grazings with long rest periods. After five years there was effectively no chicory left in the continuously grazed treatment. Chicory persisted best in treatments with the longer rest periods. In general, chicory appears more sensitive to the frequency of grazing than the intensity. Chicory is thought to be more tolerant to grazing tactics than luceme. A controlled environmeut comparison of the response to defoliation showed that young chicory plants were more tolerant than lucerne,but not as tolerant as perennial ryegrass. From these results we recommend that chicory be rotationally grazed in a four paddock system where two rnles would apply most of the time and a third in special circumstances:
1. First, livestock grazing periods on any giveu area of chicory should not exceed two weeks. At each grazing, chicory can be defoliated to remove the green leaf, but some residual stubble e.g. 50+mm must remain to minimise damage to the crowns.
2. Second, once the 'new' area of chicory (i.e. the next paddock to be grazed in the rotation) reaches 300-500 rnhI in height, stock should be moved onto that area even if the paddock they are in hasn't been fully utilised. In a four-paddock system, the application of these rules would mean that when chicory is growing fast and stocking rates are appropriate, animals would be moved at least once a week and a three-week rest would apply. When growth rates are slow, animals would only move once a fortnight to extend the rest period to six weeks. The optimal stocking rates will vary with seasonal conditions and between districts.
3. The third rule would apply only when a decline in plant density is noted. If the chicory plant density dropped to 20 plants m-2 then a combination of longer rest intervals (e.g. six weeks) and short, less intense grazing intervals one week), should be imposed to enable seed set and for some recruitment to occur.In dry years, little recruitment is likely to occur, but reduced grazing pressure would still be important to enhance the survival of chicory. In wetter years where the available forage often exceeds livestock requirements, it may be azing management'. The conclusiou was that chicory might be of most An experiment over four years investigated the interactions, competitive relations and response to plant density of chicory, white clover and perennial ryegrass. This showed that maximum productivity of chicory mixtures was achieved at densities of 50-60 plants m-2
This often requires a high sowing rate i.e. 3-4 kg ha-I . Lower sowing rates are likely to result in reduced pasture and livestock productivity, especially over the first two summers. White clover is a very suitable species to sow with chicory as both species behave in a consistently complementary fashion. There was very little evidence that chicory and white clover were competitive. An initial low sowing rate of white clover (e.g. np to I kg ha-J ) would help maximise establishment of chicory. Additional white clover could be sown later if necessary. White clover survived dry summers better in mixtures with chicory than in monoculture. Chicory is more competitive with grasses than legumes. Perenuial ryegrass did not establish very well when sown with chicory. However, there may not be any need to sow grasses as annual grass species voluntarily invade the sward, providing some additional forage over winter.If additional competition was expected from broadleaf species some grass could be included in the mixture, but it may be better to insure good weed control and maintain a high sowing rate of chicory. If chicory is being sown to provide some additional forage in the early years of a pasture with the intention that it is replaced with perennial grass species then a lower sowing rate of chicory would be appropriate.
This use of chicory was not tested in this project. but observations of commercial pastures indicate it is possible to do this. In such cases perennial grasses would be included in the original mixture. Legumes could be left out of such mixtures and sown later to avoid reducing the establishment of grasses and chicory. However, such mixtures may not be as productive as a special pnrpose chicory pasture. A short-term study over one summer examined the early growth of chicory when sown with white or subterranean clover or lucerne along with the effect of supplementary nitrogen. Plots were sown in early spring. White clover was the more productive legume, being less effected by chicory competition than the other species. There was only a limited response to applied nitrogen and this was attributed to the high levels of available soil nitrogen at the site.
These experiments were not able to resolve how best to use nitrogen in the long-term management of chicory pastures. In general the productivity of chicory will depend upon the supply of nitrogen and there is the suspicion that it is able to utilise more nitrogen at depth in the soil than other pasture species. Once this is used then additional nitrogen will be required to snstain production. Additional studies investigated a range of herbicides for broadleaf weed control in chicory. Both seedlings and mature plants were tested. Some herbicides had a small effect on chicory productivity and plant numbers, but several satisfactory chemicals were identified. The better strategy is to remove the risk of weeds before sowing chicory.
This project has significantly advanced our understanding of the productivity, management and utilisation of chicory. Future work with chicory will need to resolve the nitrogen requirements for sustained production, the appropriate analyses and role of minerals in nutritive value, tolerance to pH and salinity,optimal sowing methods and reliable means of regenerating chicory pastures.
