Phytotoxic effects of the essential oils on greenhouse-grown
bean, tomato, pepper, cucumber and aubergine plants as host plant
were determined by means of a bioassay. The highest concentration
of the essential oils used in the experiment (15gml−1) was dissolved
in DMSO–water solution (1%, v/v). These emulsions (10 ml
for each plant) were sprayed uniformly with a glass atomizer on
the surface of whole plant leaves, fruits and flowers of plants in
fruiting stages. The plants in each pot, sprayed uniformly with
10 ml of DMSO–water solution (1%), were used as negative control
groups. Sprayed plants were randomly placed on a greenhouse
bench. The differences in the appearance of treated plants compared
with healthy controls were considered as the indication of
phytotoxicity.