II. International Agricultural, Biological & Life Science Conference, Edirne, Turkey, 1 - 03 September 2020, pp.228
Weeds compete with the crop plants for available nutrients and moisture in soil, space and light.
Therefore, the physiological activities and growth of crops are negatively affected in the
presence of weeds. Using of the allelopathic effects of the plant substances is a new strategy to
struggle with weeds. The aim of this study was to investigate the alleophatic effect of water
extract of Helichrysum pallasii (SPRENGEL) LEDEB. on germination of tomato
(Lycopersicon esculentum Mill. cv. S.C. 2121) and common purslane (Portulaca olearecea L.
cv. BT Yeşilkulak) plants. Seeds were surface sterillized with 5 % of sodium hypochloride for
10 minutes and washed with sterile distilled water. Additionally, seeds were treated with 70 %
of ethanol and washed with sterile distilled water. We tested four different concentrations of
Helichrysum pallasii water extract: 5 mg/mL, 10 mg/mL, 20 mg/mL and 40 mg/mL. Sterile
distilled water was used as a control application. 10 seeds of tomato and 20 seeds of portulaca
were planted in to glass jars including two layers of filter paper. Filter papers were wetted with
5 mL of extracts for each application and sterile distilled water for control. Jars were incubated
in controlled growth room (16/8 hours light/dark photoperiod and 25 + 1 °C) for one week. This
study was conducted on at least three replicates for each application. Statistical analyses were
performed using by GraphPad Prism 8.0.1 package program One -Way Anova analysis. At the
end of the study, germination rate was calculated and shoot and root lengths were measured.
Germination rate of tomato plant treated with 10 mg/mL, 20 mg/mL and 40 mg/mL extract was
significantly lower than control and 5 mg/mL extract. Especially, 40 mg/mL of extract
prevented germination of the tomato seeds. The Helichrysum extract did not significantly affect
the portulaca germination. According to shoot length results of tomato, 5 mg /mL, 10 mg/mL
and 20 mg/mL Helichrysum extract caused importantly decrease in shoot length according to
control. Additionally, shoot length of tomato was significantly affected depends on increasing
extract concentrations. Similar results were determined for tomato root length. Importantly
decrease in shoot length of common purslane was measured in only 20 mg/mL extract
application compared to others. The all concentrations of the water extract of Helichrysum
negatively affected root length of common purslane according to control. According to our
results, the water extract of Helichrysum may have a weed control potential.