ALLELOPATHIC EFFECT AND CONTROL OF CHINESE WEDELIA (Sphagneticola calendulacea)

Abstract

Determination of allelopathic effect and control of chinese wedelia (Sphagneticola calendulacea) was conducted during November 2022 to February 2023 at Sher-E-Bangla Agricultural University, Bangladesh. Experimental results used evaluated in germination percentage and germination inhibition of different crops and to identify how other crops were affected by this weed. Sphagneticola calendulacea was identified using the visual method, and quadrates were used to determine the total biomass and relative biomass of the weeds. The infestation density of Sphagneticola calendulacea were found along roadsides, in fallow land, grasslands, and in some crop fields. The highest abundance of Sphagneticola calendulacea occurred at fallow land. The allelopathic activity of Sphagneticola calendulacea was examined against the seed growth of seventeen crop species including major cereals, pulses, oilseeds, weed seed, and vegetables. 5% aqueous leaf extract and 5% aquas leaf extract with methanol was used to investigate the allelopathic activity of Sphagneticola calendulacea to seeds and post-germinated seeds (both radicle and plumule are emerged) of test species. The following three parameters were used in allelopathic screening methodologies (a) germination percentage (%), (b) radicle length (cm), and (c) plumule length (cm). Results of Petri dishes treated with methanolic extract or leaf extract shown a complete failure of germination (0%) due to the treatment in rice, jute, cowpea, black eyed pea, pea and chickpea. Among the cereals, rice had the greatest reduction in radicle and plumule length (100%) and maize had the lowest (61% and 53%, respectively) compared to the respective control with methanol extract. Whereas, the leaf extract increase growth of radicle and plumule in both rice and wheat and highly decrease in maize and slightly in jute. For controlling this weed Filder (2,4,D-Amine) highly reduce (48%) the total biomass of the Sphagneticola calendulacea than Sunup 480 SL (glyphoset) and Weednil 5EC (Quizaloph-PEthyle)

7% and 8%, respectively. Therefore, an integrated management approach is urgently needed to control the spread of this invasive weed.