#bioherbicides

Studies were carried out to scrutinize allelopathic potential of aqueous extracts of Parthenium hysterophorus L. on germination and growth of maize crop. Seed germination, seedling growth and biomass production was also examined. Distilled water was use as a control treatment. Completely randomized design (CRD) was used along with five treatments and three replications. Results revealed that there is significant difference among treatments applied. All extracts of Parthenium stimulate germination of maize when compared with control. Among the treatments applied seed treatment has very pronounced result on germination percentage, germination index, and mean germination time and germination energy. Whereas seedling parameters are positively affected by application of root extracts except for seedling vigor index and shoot dry weight. However, Shoot extracts has also encouraging outcomes on emergence energy and emergence percentage. It was suggested that further experimentation was needed to explore the stimulatory role of Parthenium on maize so that this weed can be used as bioherbicide.

This study proposes the evaluation of the phenolic composition of leaves and stems extracts of Rosa canina (Dog rose) and their herbicidal abilities measured using assays of germination rate (G) and germination speed (GI) of lactuca sativa (Lettuce), phalaris truncata and raphanus raphanistrum seeds and assays of its seedling growth. Leaves and stems of dog rose were rich in total phenolics and total flavonoïds with comparative contents. Whereas flavones/flavonols were abundant in leaves extracts and in traces in stems extracts. G and GI of target species seeds and root and shoot length of its plants were reduced from the lowest concentration of both extracts. Reductions of G and GI were more important in presence of leaves dog rose extracts compared to those noted with stems extracts. Raphanus raphanistrum was the most sensitive target species to both extracts. G and GI of this weed were canceled from 30g/l of leaves extract. Root and shoot growth of target species were more inhibited in presence of dog rose leaves extracts. Inhibitions reached 100% from concentrations of 40g/l, 60g/l and 90g/l respectively for wild radish, canary grass and lettuce. The findings allow us to demonstrate that leaves and stems from dog rose could be a prospective residual vegetable source of valuable phytochemicals, for future applications in the field of agroecology and biological weed control.