Aspects of Applied Biology 101, 2010 Non Food Uses of Crops The agricultural production of woad and the derivation of indigo

By IAN HOWARD

The Woad Centre, Rawhall Lane, Beetley, Dereham Norfolk NR20 4HH, UK Email: [email protected] www.woad- inc.co.uk

Abstract

Ian and Bernadette Howard have established a company called Woad-inc, (www.woad-inc. co.uk). They were involved with the EU-funded Spindigo project (2000-2003) as growers of woad (Isatis tinctoria) in the UK. They were involved in growing the woad crop on a commercial basis, i.e. planting the seed, taking care of the agronomy, harvesting the leaves and providing accommodation for laboratory-trials, water and electricity. When Spindigo finished in 2003, the company started their own research work to establish a higher yield of indigotin and enriching the purity of the pigment to establish a saleable market product. The high costs involved required a niche market to sustain its unique position as an alternative to the synthetic and in some cases, carcinogenic dyes, which are so popular now. Today, Woad-inc has moved on to provide quality products from natural fibres and toiletries free from chemical preservatives and colourants which are not tested on animals. The company retails through its own shop, by mail order and has a shopping cart for on- line shopping with orders now coming from all over the world. Shows are attended and interest is very upbeat, which gives the impression more people want natural products. Woad-inc is constantly expanding its range of products and welcomes media interest, as advertising is so expensive. An experimental plot of weld (Reseda luteola) is being developed to incorporate a natural yellow into the products.

Key words: Woad, Isatis tinctoria, weld, Reseda luteola, natural fibres, Spindigo

Introduction

This conference covers the non-food use of crops, bringing together research and progress of renewable materials and looking at any new diversification in today's market. Our contribution is to demonstrate the market potential for natural pigments and the use of pharmaceutical and personal care products from woad.

Materials and Methods

Land is allocated in the autumn and prepared by ploughing and cultivation, fertilizer is applied at the rate of 600 kg ha-1. The land is sprayed with a pre-emergence herbicide at approximately 3 L per hectare, depending on soil type, and harrowed in.Woad seed in silicules is drilled at 5 -9 kg ha-'. We trialled threshing the silicules and hulling the chaff to obtain the small seed and

123 purchased a Miniair S air precision vegetable drill to drill the seed but we experienced poor and patchy germination, and so reverted to drilling the seed in the original silicules, using an Accord pneumatic drill. Immediately after drilling is finished, the land is flat rolled and sprayed with herbicide, again at 3 L ha-'. There is no further spraying whatsoever, so no chemical comes into contact with the leaf or plant. We feel this is very important to communicate to our customers. If any weed becomes a problem prior to first leaf cut then we employ hand labour to eliminate the invaders as it is imperative to have a weed free crop. This, again, becomes expensive and affects the end price. We have found that if the weather is such that the plant is slow growing, then weed infestation does become a problem. We do not bother about insect invasion as we do not want any chemical to contact the leaf. In July we like to make our first leaf cut. We use a converted ragwort puller which we believe cuts and treats the leaf kindly. The leaves are transferred to a trailer, avoiding any compaction. We then wash the leaf. This is done because it is essential the leaf is as completely free of soil contamination and foreign bodies. The washed leaves are placed into mesh nets each containing about 80 kg; three nets are used per process, which are placed into dairy wash tanks. Hot water is added and, when the tanks are full and the leaves in the nets are covered with the heated water (some 300 L are used each process), after a short period the nets containing the leaves are lifted out from the tanks and strained. The resulting brown/gold liquid extract is then pumped into an open tank and cooled immediately so that a temperature drop of some 40/50°C is obtained within 3 to 4 min. The method of rapidly reducing the temperature is achieved by using a dairy ice bank converted to procure the lowest possible reduction. Once the extract has cooled, we raise the pH with calcium hydroxide to over 10.5 from a base pH of approximately 6.8. The extract is then passed to another open tank where it is oxidised by circulating the extract using a submerged pump. This oxidized liquid is then passed to a further tank for settling. As the purified product is insoluble in this container, it's then possible to pump off the surplus water. After further water extraction a sludge is obtained, which is filtered through a fine gauze, the solids extracted, dried and then ground to a powder. Not only are the leaves of the plant used for the dye we make woad balls between stages in processing. These balls, which may be the only balls made commercially in the world, are very popular with the old-fashioned dyers and 're-enactment' groups all over. Additionally, woad silicules are threshed, hulled and the seed cold pressed for the oil used in our toiletries.

Results

Since its conception, Woad-inc has aimed to provide quality products. What we have now achieved is a powdered pigment for dyeing, which has been independently assessed as exceptional in purity. We have been able to dye a large selection of fabrics and threads to develop a range of quality textiles. We have established a barn conversion, which contains an area where we can give talks, hold discussions and have workshops, which have proved to be very successful. In our converted barn a shop has been created which sells all our products and is usually met with the comment 'WOW' as people walk in the door. Ian has also found his talks and lectures go down very well, and we have been able to incorporate a small demonstration to give a touch of "the indigo magic" and offer a small sample of our shop items for sale. Our strength has come from market research, which prompted us to go into homewares. We decided to try to keep the natural aspect and promote the slogan "Blue dye with green credentials" which in turn gave us headlines of "Natural Blue colour from the woad plant" and "Exclusive goods dyed without harmful chemicals".

124 We have been successful in what we have done with our products, incorporating bamboo into towels at first, then using bamboo in cone dyed yarn, which boosted the natural aspect for us. We commissioned and offered a limited edition range of bamboo/wool, alpaca/mohair throws and cushions. These were made to be heritage collectable pieces. With imported Italian merino wool we found a proven market for clothing with a modern flair. Cotton and silks dye very easily by hand, offering goods, such as scarves, at the lower price range. Woad balls sell well, and are a good talking point. Our toiletries are enhanced with woad oil, which has the reputation of being soothing to the skin. We use the extracted oil in all our toiletries and we do not use any chemical preservatives or colourants, and they are not tested on animals.

Discussion

There is no doubt we have been in the forefront of the revival of woad in the UK. Cultivating eco-friendly dyes on a large scale is still experimental and has along way to go. There is a difference in taking a product from the garden or hedge or the open fields. In our case we have taken our production to its limits. We have been pioneers and taken woad from the laboratory to a commercial enterprise. However, at the moment, there are no indications that woad and other natural dye plants are sustainable without R&D. One has to look at the situation with realism and common sense. In a world where the anticipated growth of the population is expected to rise dramatically and people have to be fed, it is my experience that farmers who have grown food for generations will continue to do so. They will not change. Natural dye colour production in the UK is extremely costly and we have found it very difficult to educate people to change their habits towards eco-friendly ways, which are expensive to the pocket. There is sufficient expertise in the UK to research what has to be done, but what is really needed is entrepreneurial skills and sound funding. We have been quoted as the alchemists transforming East Anglian fields into liquid gold. This sounds good but the reality is incorrect. We regard what we have done as successful, rewarding and fortunate. The attraction is a 'buzz' and the colours are so variable and not easily repeatable. The UK climate is a big problem for successful woad cultivation. For instance, in the last two years we have only been able to have one harvest and the previous year we managed two cuts, but the second was late and, therefore, the leaf was small.One year we drilled in April, only to find a sharp cold spell upon us and the whole crop vernalized so that only a seed crop was taken. It is no secret that woad likes long, hot sunlit days. The climate can be blamed for the fact that we are at a disadvantage when we are approached by large leading companies to whom we cannot supply bulk orders. This low production also makes the core product expensive. On the other hand, we are working with young designers with small numbers, who have advanced thinking and, hopefully, are entrepreneurs. In the future we must look at the impact natural dyes have on the environment. People are aware of nasty chemicals. We replace all our used leaves back on to fields from whence they came. The waste waters are also pumped on to the fields, not into drainage channels, but these do contain contaminants. Hydrosulfite, for instance, is environmentally undesirable and so are the mordant's used in other dyes that we will want to use. The way to proceed is to do the trials and experiments and learn by errors in the hope of increasing business and awareness. As a business growing and promoting the use of non-food crops we have been approached by InCrops based at the University of East Anglia in Norwich, to join a partnership project designed to stimulate the commercialisation of alternative crops. This group offers verbal support and expertise accessing pre-commercial research, market development and intelligence, crop development and agronomy. They offer knowledge through universities and supply chains. Together we have been able to exchange ideas and hope to develop our knowledge. There are so many avenues we have not

125 touched on yet. There are paints and preservatives to be investigated. There are healing properties potential in the leaf, which contains 30% gamma linolenic acid. Great interest has been shown in the medicinal element since the media looked at the possibility of the presence of the compound glucobrassicin. Also, we would like to think we might be able to make a contribution towards help in cancer research. Indirubin is basically a waste product to us and can be made easily and its medicinal properties as a cancer cure are being researched. The oil from woad seed, although expensive to extract, is presently, relatively undeveloped and needs to be examined for other uses. At the moment, it is very popular in our toiletries. As far as our own situation is concerned, we have taken the business as far as possible in relation to harvesting and processing. These areas need capital funding to expand, but we are very mindful of the fact that our pigment with its high purity is still much sought after. In fact when we are cone dyeing, we work on a ratio of 20 g pigment to colour 1.5 kg of either bamboo or merino wool. This results in a Wedgwood/RAF blue colour, which incidentally is the colour customers seem to prefer.

Acknowledgements

We would like to acknowledge the help and encouragement we have received from, Dr David Cooke, Dr Kerry Gilbert, Prof Philip John, Jenny Balfour Paul, Jill Goodwin, and many more.

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