A, The ALLELOPATHIC EFFECT OF AQUEOUS EXTRACT OF CARTHAMUS TINCTORIUS ON GERMINATION AND INITIAL SEEDLING GROWTH OF ORYZA PUNCTATA

ABSTRACT Chemical weed control method creates environmental hazards and residual effects in crops and soil. Alternate approach to control weeds is getting attentions in sustainable production system. Aqueous extract of crop is an important technique to control weed and also environment friendly and cheap. To investigate the herbicidal potential of aqueous extract of winter crop Carthamus tinctorius (safflower) on summer weed Oryza punctata (red rice) seed germination and initial seedling growth, a study was planned in Weed Science Laboratory. In this study, seeds of C. tinctorius were incubated in seven concentrations (0, 0.25, 0.50, 1, 2, 4, and 8%) of different parts i.e. leaves, stem, flower of C. tinctorius. All the tested concentrations of various plant parts of C. tinctorius significantly inhibited the mean emergence time, germination index, germination percentage (%), time taken to 50% germination as well as growth of O. punctata weed. However, maximum mean emergence time (4.73 days), time taken to 50% germination (4.19 days) was noted at 8% concentration and germination index of O. punctata was noted at 0.25% concentration when flower extract was applied. Leaf aqueous extract at the concentration 8% caused the lowest root length (1.53 cm), shoot length (4.51 cm) and fresh weight (54.72 g) of O. punctata. Results suggested leaf and flower extract of C. tinctorius at concentration (8%) can be used potential bio-herbicide for the control of red rice. Key words: Allelopathy, seedling growth, inhibitory, weed growth, plant parts, promotor