Allelopathy is a phenomenon of direct or indirect, beneficial or adverse effects of a plant on its own or another plant through the release of chemicals into the environment. This experiment was carried out to determine the allelopathic effect of Cyperus rotundus L. (purple nutsedge) tuber aqueous extract on seed germination and initial growth of Glycine max L. (soybean) seedlings. The experiment was performed in completely randomized (CRD) design with five replications, using a range of concentrations of aqueous tuber extracts of nutsedge, i.e.: 0%, 5%, 10%, 15%, 20% and 25%. The petri dish experiment showed that with increase of the tuber extract concentration, a significant increase was noted in mean germination time (MGT), significant decreases in germination index (GI), growth tolerance index (GTI), wet weight seedling, dry weight seedling and  length of soybean seedling.

ABSTRAK Telah dilakukan transesterifikasi minyak goreng bekas menggunakan katalis CaO/MCM-41 dari lumpur Lapindo dengan metode sonokimia. Pemisahan lumpur Lapindo dilakukan dengan metode refluks menggunakan HCl 6 M dan NaOH 6 M. Lumpur hasil refluks kemudian dianalisis dengan XRF dan digunakan sebagai sumber silika dalam sintesis MCM-41. MCM-41 disintesis dengan metode sonokimia selama 150 menit dan dianalisis menggunakan XRD, FT-IR, TEM, dan GSA. Katalis Ca diembankan pada MCM-41 menggunakan metode impregnasi basah dengan variasi pengembanan 1,15; 1,29; 2,39; dan 3,25% (b/b)

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Stelechocarpus burahol is one of the medicinal plants that contains flavonoids. The study was carried out to know flavonoid production of cultures in vitro S. burahol from mesocarp explants. Mesocarp explants were cultured on MS medium containing different combination and concentration of plant growth regulators i.e. picloram (5, 7.5 and 10 mg/L) and 2, 4-D (10, 15 and 20 mg/L) under dark condition. Induction of callus formation started on the 20.29 th to the 29.86 th days. Medium supplemented with Picloram and dark state proved to be the best condition for optimum callus induction from mesocarp explants of S. burahol. Callus grown on medium with the addition of 7.5 mg/l Picloram produces the highest flavonoid. The maximum production of the secondary metabolite was obtained from 8 weeks old callus. However, by the time of callus ageing, its output has declined. It could be concluded that callus cultures from mesocarp S. burahol can be used for flavonoid production.