OECD 227: Terrestrial Plant Test - Vegetative Vigour Test


Non-target plants, i.e. plants in natural and semi-natural habitats within the agricultural land such as hedgerows, field borders, meadows and other small biotopes may unintentionally be exposed to to plant protection products.
The OECD guideline 227 assesses the potential effects on plants following deposition of the test item on the seedlings at the 2-4 true leaf stage.

Study Design

Plant species

The plant species selected for the test should derive from different plant families to consider the taxonomic diversity and should give reliable and reproducible results. Usually six to ten plant species are chosen according to the specific properties of the test item and the intended use. Among them could be for example Allium cepa (onion), Zea mays (corn), Brassica napus (oilseed rape), Cucumis sativus (cucumber), Glycine max (soybean), Helianthus annuus (sunflower), Solanum lycopersicon (tomato) or Stellaria media (common chickweed).

Test rates

Test rates are usually determined in a range-finding pre-test. The rates for the pre-test are calculated based on the maximum application rate used in the field.










Course of the test

Plants are grown from seeds to the 2- to 4- true leaf stage. The sowing takes place on different dates to ensure that all species are in this stage at the application day. The test item is then sprayed onto the seedlings. The test item concentration has to be confirmed analytically. After the application, the plants are evaluated weekly for effects (phytotoxticity) in comparison to water treated control plants for 21 days. At the test end the endpoints are measured and recorded.

Growth Conditions

The studies are performed in a growth chamber with controlled, optimized test conditions for standardised studies. The temperature is 22 °C during the light period and 18 °C during the dark period (mean 22 °C ± 10 °C) and humidity is 70% ± 25%. During the photoperiod of 16 hours light the intensity is 350 ± 50 µE/m2/s.
For special needs, more differentiated studies and research these conditions can be adapted within a wide range.


Endpoints are mortality and shoot fresh weight. If the test is conducted as multiple rate test, effects on fresh weight are reported as ERX (Effective Rate) for each species individually or as NOER (No Observed Effect Rate) in case of a limit test.
Additional parameters that can be assessed are shoot height and shoot dry weight. Effects on these parameters are reported as ERX for each species individually.
Phytotoxicity (e.g. chlorosis, necrosis, deforamtion) and growth stages (BBCH code) are recorded. If the test is conducted as multiple rate test an ERX (effective rate) caluation on phytotoxicity is possible.

Guidelines and Literature

  • OECD Guidelines for the Testing of Chemicals No. 227 “Terrestrial Plant Test: Vegetative Vigour Test”