Backyard Aquaponics
A place to discuss aquaponics

9.1 Yacon (Polymnia sonchifolia)

9.1.1 Background

Yacon is a South American plant of the sunflower family which produces edible tubers that can be eaten raw or cooked. The plant has been in New Zealand for many years and the interest is now in the specific carbohydrates which occur in tubers.

The carbohydrates are fructo-oligosaccharides which are most suitable for use as prebiotic nutraceuticals to manipulate the hindgut microflora from undesirable species to healthy species in intensive livestock and poultry rearing and lessen or replace the use of antibiotics.

The use of prebiotic feed formulations for this purpose is not yet practised in New Zealand but has been proven experimentally overseas.

9.1.2 Market situation

The development of an industry growing and processing yacon is dependent on clinical trials being undertaken in New Zealand to prove the effectiveness of the prebiotic method of disease control.

The carbohydrates in yacon may also have a place as a sweetener in beverages but this use is also as yet underdeveloped.

9.1.3 Agronomic requirements

Yacon grows up to 2 m tall as a herbaceous perennial. The crowns are planted in mid spring with tubers forming in autumn and being ready to harvest in winter. The tubers are attached to the crown of the plant, and when lifting the crowns the tubers need to be broken off.

In trial programmes this has been undertaken by hand and mechanisation of this process needs to be developed. The crowns also need to be saved as replanting stock. With the present state of knowledge, labour input is high.

The crop is underdeveloped agronomically and without effective weed control herbicides. The crop is underdeveloped agronomically and without effective weed control herbicides.

9.1.4 Taranaki's potential advantage

Yacon would grow well in the warm moist conditions of Taranaki. However, at the present time comparatively little is known about the agronomy of the crop and environmental influences on its growth and quality.

9.1.5 Postharvest and transport

Yacon tubers need to be washed after lifting and then dried. Cool storage of fresh tubers is necessary to prevent sugar breakdown. Once dried, the product would need to be milled to enable it to be used in feed formulations.

9.1.6 Future possibilities

The use of prebiotics in intensive livestock production in New Zealand is unsubstantiated and not practised. If clinical trials provide a positive direction for their use, then the production of yacon could develop into a significant industry. The prebiotic approach to livestock production could also increase in significance under an 'organic' farming umbrella.

Pics below are the harvest of one plant.. And one fairly hard to see plant in the background...