Abstract:
A Pot culture experiment under green house condition was conducted to study the allelopathic effect of
Lantana camara (L.) and Parthenium hysterophorus (L.) weeds on germination and growth behaviour of
Thespesia populnea (L.) tree species. The experiment was laid out in Randomized Complete Block Design
(RCBD) and replicated thrice. Combination of two invasive weed species viz., Lantana camara and
Parthenium hysterophorus) and four concentration levels of aqueous extract viz., 10, 20, 30 and 40% were
assigned as main treatments with application of normal water as control. The results revealed that,
application of whole plant aqueous extract of Parthenium hysterophorus at higher (40%) concentration
significantly recorded lower seed germination percentage (26.7), germination value (3.0), germination
index (0.14), germination relative index (5.7) in Thespesia species than at lower concentration of
Parthenium hysterophorus and Lantana cam ara weed species. Whereas, number of days required for the
germination of Thespesia seed was maximum (9.05 days) in application of aqueous extract of Parthenium
hysterophorus at 40% concentration. Thespesia seedlings growth and growth behaviour were also
significantly inhibited by the whole plant aqueous extract of Parthenium weed at higher concentration,
which reduced shoot length (12.6cm), root length (9.2cm), dry weight (12.6 mg plant1), dry weight based
vigour index (338) and chlorophyll content (15.7 pmol chlorophyll nr2) at 60 days after sowing.
