Table 4 Comparison of the indigo extraction methods between Hainan Miao and Li dyers on Hainan Island, China
| Â | Indigo-yielding species | Part used | Harvest season | Fermentation duration/h | Amount of lime | Oxygenation method tools | Production frequency/year |
|---|---|---|---|---|---|---|---|
Li | Strobilanthes cusia (Neek) Kuntze | Leaves and stems | All seasons (20%); July–October (80%) | 24 (90%); 24–48 (10%) | 450g (10%); 250–500 g (80%); 500–1000 g (10%) | Homemade bamboo tools | Once (10%); twice (47%); once to twice (33%) |
Indigofera suffruticosa Mill. | Leaves and stems and ripe fruit | July–September (95%); October–November (5%) | 24 (95%); 24–48 (5%) | ||||
Indigofera tinctoria L. | Leaves and stems and ripe fruit | July–September (91%); October–November (9%) | 24 (15%); 24–48 (85%) | ||||
Hainan Miao | Strobilanthes cusia (Neek) Kuntze | Leaves and stems | All seasons (50%); July–December (48%); November–January (2%) | 48–72 (22%); 72–96 (70%); 72–168 (8%) | 250 g (17%); 250–500 g (59%); 200–500 g (24%) | Plastic scoop | Once (44%); once to twice (33%); twice to three times (23%) |
Indigofera suffruticosa Mill. | Leaves and stems | 24–48 (10%); 48–72 (70%); 72–120 (20%) | |||||
Indigofera tinctoria L. | Leaves and stems | 24–48 (14%); 48–72 (73%); 72–120 (11%) | |||||
Persicaria tinctoria (Aiton) H.Gross | Leaves and stems | 24–72 (69%); 72–96 (19%); 72–168 (12%) | |||||
Wrightia laevis Hook.f. | Leaves and young shoots | 24–72 (36%); 72–120 (45%); 72–168 (19%) |