Information and Recommendation: July 2015 Dealing with Problems of Tropane Alkaloids in Weeds

Recommendation: Dealing with problem-weeds with TA’s: RAPUNZEL Naturkost; Created by: Strategic Sourcing; Date: 07/2015; Version 2 1

INTRODUCTION

Since the end of 2014, the governmental agencies increased analysis for tropane alkaloid of arable crops. These alkaloids are found naturally in various plants, particularly in night-shade plants e.g. in thorn apple (Datura stramonium) or henbane (Hyoscamus niger) (above all the tropane alkaloids scopolamine and atropine). These nightshade plants also grow on arable land. In recent years, the presence of these plants seems to have increased in some regions. These weeds can accidentally be included at harvest and can cause a contamina-tion of the crop. Investigations revealed especially for the thorn apple to be a problem weed. With this information sheet, we focus on thorn apple. BACKGROUND Toxicity of tropane alkaloids:

For risk assessment, the European Food Safety Authority EFSA published an acute reference dose (ARfD). Referring to the sum of atropine and scopolamine (group ARfD) as health-related reference value amounting to 0.016 micrograms/kg body weight (BW), this value is currently taken as basis for risk assessment. Link: http://www.efsa.europa.eu/de/efsajournal/pub/3386.htm The sap of a weed plant or single seeds can already lead to a contamination of the crop, making the crops no longer marketable. IDENTIFICATION

Should you be unsure about the identification of those problem weeds your local advisor of an organic farming association or a public authority may certainly help you.

Thorn apple (Datura Stramonium)

Pic 1: Thorn apple, young plant. Lanzeolated cotyletons. Source: Rapunzel, MM

- The thorn apple prefers a humid, rich-in humus and nitrogen- soil and also a warm climate. - It is an annual plant. The green plant grows from bushy to upright depending on the available space (0.20 to 1.5m). The stems are forked and bald. - In the youth phase (from the 2-leaf-stage on), the plants are easy to be confused with other plants (for example with the white goosefoot, see Pic. 2).

Pic 2: Left: Thorn apple, white stem base, Plant more stable and resistant ; Right: White goosefoot: violett stembase, Plant soft. Source Rapunzel, BA

Information and Recommendation: July 2015 Dealing with Problems of Tropane Alkaloids in Weeds

Recommendation: Dealing with problem-weeds with TA’s: RAPUNZEL Naturkost; Created by: Strategic Sourcing; Date: 07/2015; Version 2 2

Pic .3: Thorn apple: Plant height 1m, Source: Rapunzel, MM

Pic .4: Thorn apple: Blossoms and fruits (Blossoms <10 cm) Source: Rapunzel, BA - In the adult plant leaves are toothed, about hand size, dark green on the surface and grey-green on the underside. - Thorn apple germinates approximately in May (depending on climate) and forms blossoms from June to October. These open only towards the night. - Self-pollination. - The trumpet-shaped flowers are five-pointed. The flowers are yellowish to white. - Capsules grow at the stem axils, where they stand straight up. The capsules are normally spiky from outside. They spiky capsules are about 2-4 cm long and 1.5-3.5 cm wide. When ripe, the capsule opens up. One capsule contains up to 500 black kidney-shaped seeds. - Thousand-kernel-weight is 7-11 g. - Animals usually spread the seeds.

- The thorn apple has a very sweet and strong odor, which is usually perceived as unpleasant (somewhat reminiscent of elderberry leaves, but is much stronger). The smell can already be smelt from several meters away. Sources: - https://de.wikipedia.org/wiki/Gemeiner_Stechapfel - Own research of Rapunzel Henbane (Hyoscyamus niger)

Pic 5: Henbane, young plant. Round cotyledons Source: Julius Kühn Institut (JKI)

Pic 6: Henbane, blossom. Source: JKI - Henbane is significantly less common than thorn apple (Source: Bundesamt für Naturschutz BfN).

Information and Recommendation: July 2015 Dealing with Problems of Tropane Alkaloids in Weeds

Recommendation: Dealing with problem-weeds with TA’s: RAPUNZEL Naturkost; Created by: Strategic Sourcing; Date: 07/2015; Version 2 3

- Henbane is, as the name implies a herbaceous plant that grows 30-60 cm high. - - The leaves are egg-shaped and toothed. - Henbane can germinate annually or biennially. - Funnel-shaped flowers are yellowish-white, purple veined. The flowers grow in the leaf axils. Blossoms from June to October. - The fruit is a bulbous 1.5 cm long capsule. - The seed is grey-brown, furrowed, about 1 to 1.3 mm in size. - Thousand-kernel-weight: 0.65 g (Source: JKI Institute). Source:https://de.wikipedia.org/wiki/Schwarzes_Bilsenkraut REGION - ENVIRONMENT

The mentioned plants seem to spread more in recent years in some regions due to climate change: from South-Eastern Europe to North- Western Europe. Especially in Austria, Hungary, Ukraine and Romania, higher incidences especially of the thorn apple have been reported. In Germany, thorn apple has been increasingly detected both on arable land in Eastern Bavaria and in Eastern Germany. In addition, experts report an entry of seeds on arable land from permanent landscaped flower strips and extensification areas. A high awareness of farmers is important. E.g., potential weeds are found on brownfields, flower strips, on roadsides. CULTURES

An increased incidence of problem weeds has been observed in the following crops:

- late germinating (e.g. maize, millet, amaranth, sunflower, buckwheat)

- crops that are easy suppressed by weeds (e.g. flax)

- fast drying crops (e.g. soybean)

Even if ground-covering crops are put in crop rotation, attention has to be paid on: - dissemination and establishment of problem weeds. - open areas (open spaces, where no cultivated plants have risen).

Pic 7: Thorn apple in maize: Universität für Bodenkultur, Prof. Glauninger WEED CONTROL

"Nip it in the bud": This is one of the most important rules concerning these types of weeds. A high awareness of the farmers is necessary! If small plants (e.g. spread by birds) are safely removed at an early stage, there is no further spread. The easiest way is to remove problem plants manually before inflorescence. Important is to wear gloves, as the substances e.g. from thorn apple can penetrate the skin. A strict cure is probably the only solution with heavily affected areas. E.g. since thorn apple only germinates in May, it may be advisable in some cases to leave the land for one year from production and safely remove accumulating problem crops by appropriate tillage. This recommendation reflects our current knowledge. However in accordance with good farming practice: it is the farmer’s responsibility to make sure with appropriate measures that the crop is free of critical tropane alkaloids.

Information and Recommendation: July 2015 Dealing with Problems of Tropane Alkaloids in Weeds

Recommendation: Dealing with problem-weeds with TA’s: RAPUNZEL Naturkost; Created by: Strategic Sourcing; Date: 07/2015; Version 2 4

HARVEST

Accidently co-harvested weeds may lead to a contamination

- one one hand by foreign seeds (e.g. thorn apple): This seems to be the case in millet-

- Or by green plants (e.g. Datura Inoxia): Through late germination at harvest, the weeds are still in a green state and therefore very juicy. combine harvester, the plant sap of the weed can contaminate the crop.

Thorn apple contains the alkaloids atropine, scopolamine and hyoscyamine (up to 0.6% in dry matter) in all plant parts.

Pic 8: Combine harvester at work, Source: Rapunzel, MM

PROCESSING – CLEANING

A cleaning out of relevant foreign seeds by conventional cleaning methods (incl. optical remover) is possible in case of e.g. thorn apple. However, a cleaning out does not seem to be generally sufficient to avoid contamination. Already the contact with plant parts or immature weed seeds can lead to a contamination.

Pic 9: Seeds: Thorn apple seeds in comparison to Maize and millet seeds, Source: JKI CROP ROTATION

It is important to implement a diverse crop rotation. Winter and summer crops should alternate. ANALYSIS

Until about mid-2014 there were still some uncertainties concerning the analysis results on tropane alkaloids. Since the EU demanded increased analysis of tropane alkaloids, based on the EFSA recommendations some laboratories were working on improving the reliability of the analysis results. Since the end of 2014, a good reliability from experienced laboratories can be expected. For inquiries, please directly contact your cultivation consultants. We are looking forward to hearing from you concerning more information, questions etc. Contact at Rapunzel Naturkost GmbH: Barbara Altmann Email: barbara.altmann@rapunzel.de Phone: +498330 529-1255