Growers of aromatic herbs in Albenga and other parts of Italy might be interested to evaluate the addition of Stevia rebaudiana to their standard assortment in cultivation. Stevia rebaudiana has great economic potential as a natural alternative to sugar and artificial sweeteners. Dry Stevia leaf is up to 30 times sweeter than sucrose. The sweetness mainly derives from two glucoside compounds: stevioside (3-10% of dry leaf weight) and rebaudioside A (1-3%) and the extract is almost completely free from calories. Leaf yields of 2850 kg/ha with a stevioside concentration of 105 mg/g have been achieved in Canada. This is equivalent to 66.2 tonnes per hectare of sugar. The glucoside concentration in Stevia leaves will vary according to the method of propagation, daylength and agronomic practices.

These highly stable glucisides do not darken with cooking and they have been used for other beneficial properties including the control of appetite, hypertension and diabetes. The leaf extract also contains other products including vitamins, minerals and oils. As a sweetener/flavour enhancer it is being used widely in Japan, China, Korea, Israel, Brazil and Paraguay. The plant is harvested whole, just before flowering to obtain maximum glycoside content. The harvested plants are then dried and threshed to remove the stem material. Leaves can be sold in this condition or further processed. While extensive testing and utilization of Stevia in Japan has revealed no harmful effects, in some countries it is only licenced for use as a dietary supplement and a skin care product.

Stevia rebaudiana (Asteraceae), is a short day plant growing up to 1m tall in the wild. It is a perennial herb native to Brazil, Venezuela, Colombia and Paraguay and produces an extensive root system, brittle stems with small elliptical leaves. It will grow naturally on infertile, sandy acid soils with shallow water tables. This is normally in areas like the edge of mashes and grassland communities. Stevia is grown as a perennial in sub-tropical regions but in agronomic situations and in mid to high latitude regions, it is grown as an annual. The plant's natural climate is semi-humid subtropical with temperature extremes from 21 to 43 C, averaging 24 C.

Reproduction in the wild is mainly by seed, but seed production and viability tends to be poor. Production seed yields of up to 8.1 kg/ha have been recorded but it is common to have under 50% germination (black seed germinate much better than tan (brown) seed which is mostly inviable. For the above reason vegetative propagation by stem cuttings or micropropagation of superior clones is preferred.

Young plants or seedlings are sually transplnated into the field when they are 6-7 weeks old. Seeds need to be germinated under glasshoue conditions.

Further research and development needs to be carried out to find optimum growing conditions, seed germination, cultural practices and a land-race (clone) suited to regional climatic zones of Italy. For further information, contact: Dr Rob Fletcher, Email: r.fletcher@mailbox.uq.edu.au www.newcrops.uq.edu.au For other sources of information, the following websites might be useful: www.riverhouse.com.au, http://res.agr.ca/lond/pmrc/faq/menu.html, http://res.agr.ca/lond/pmrc/herbs/stevia.htm, www.healthfree.com/herbgarden/stevia.html Also try: Euganea Floricoltori Coop a r.l. Fax 049 9130377, E-mail: info@euganea.org,