Abstract:
An experiment was conducted during the period of January-June, 2017 at the Agricultural
Chemistry Laboratory and net house (field condition) to investigate the phytotoxic effects of
ten medicinal plants (cirota, bohera, anantamul, nagesshor, ashok, arjun, bashok, akandho,
darucini and rosundi) aqueous extract on germination and seedling growth efficiency of five
selective plants, three dicot (cauliflower, broccoli and tomato) and two monocot (foxtail millet
and barnyard grass) under both condition. The aqueous extracts of medicinal plants at six
different concentrations (control, 0.001, 0.003, 0.01, 0.03 and 0.1 g/ml) were examined on five
plant species in the laboratory condition and concentrations (control, 1, 2, 3, 4 and 5 g/ml) were
examined only for bashok extract on five plant species in the net house (field condition).
Result indicated that the germination efficiency, plumule length (cm) and radicle length (cm)
and dry weight of plants were completely inhibited at the highest concentration of aqueous
extracts (0.1g/ml) where at least inhibition was observed at control. There was a clearly
observed variation of treatment effect between the monocot and dicot plants where monocot
plants (foxtail millet and barnyard grass) showed great treatment effects than dicot plants
(cauliflower, broccoli and tomato) and out of three dicot plants, the least variation of treatment
effect was found in tomato because of its larger seed size and hard seed coat . Among the (leaf
& flower) aqueous extract of ten medicinal plants, the treatment effect of cirota, bashok and
rosundi caused the greatest variation in the germination percentages, plumule length, radicle
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length and dry weight of five selective plants but mostly in foxtail millet and barnyard grass.
Thus, phototoxic effects of cirota, bashok and rosundi may reduce weed competition with crops
by significantly affecting the germination and seedling growth of foxtail millet and barnyard
grass.
