Potential Allelopathic Candidates for Land Use and Possible Sustainable Weed Management in South Asian Ecosystem

Abstract

Weed management is one of the significant challenges of field crops since weeds pose a remarkable threat to crop productivity in South Asian countries, including Bangladesh. Allelopathy, a phenomenon whereby secondary metabolites produced and released by one plant species influence the growth and development of other species can be exploited in sustainable management. The focus of this study was to evaluate potential allelopathic plant species which can be further explored as alternatives to synthetic herbicides or incorporated as part of integrated weed management in sustainable agriculture. Two hundred fifty-two plant samples from 70 families were collected from Bangladesh and evaluated with the sandwich bioassay. Thirty-one percent of the samples showed significant allelopathic potential on lettuce radicle elongation. Among the species that showed substantial inhibition, more than 7% of the samples showed higher inhibition (HI) and 25% showed moderate inhibition (MI) on lettuce radicle. Fruit pulps of Couroupita guianensis (95.4%), fruits of Phyllanthus emblica (95.4%), and Acacia concinna (95.4%) showed the highest inhibition on lettuce radicle elongation. In contrast, the leaf of Bombax insigne had growth promoting activity by stimulating radicle (23%) and hypocotyl (80%) elongation of lettuce seedlings. This result suggested that the species with significant plant growth inhibitory potential may play a vital role as an alternative to the increasing use of synthetic herbicides for sustainable weed management in agricultural land.

Evaluation of Potential Volatile Allelopathic Plants from Bangladesh, with Sapindus mukorossi as a Candidate Species

“…The dish pack (DP) method [29] is a reliable and established bioassay for detecting the presence of volatile allelochemicals. This method was adopted [29][30][31][32][33] for the evaluation of a large number of plant samples, to identify volatile allelopathic plants. For this study, the DP method was adopted to evaluate the volatile allelopathic potential of 103 plant samples (March-June 2018).…”

“…The statistical analysis was performed by evaluating the mean (M), standard deviation (SD), and the standard deviations value (SDV), using a frequency distribution curve for Microsoft Excel Ekuseru-Toukei 2012 by a special program (Social Survey Research Information Co. Ltd.). The concept of the SDV has been used by previous reports [28][29][30][31][32] to evaluate the criteria of allelopathic activity among the samples. The criterion of the standard deviation value (SDV) was used to estimate the range of significant effects of the species.…”

First Broad Screening of Allelopathic Potential of Wild and Cultivated Plants in Turkey

“…The method has been adopted [2,12,15] widely to screen large numbers of plants and successfully determined the allelopathic activities of plant materials under laboratory conditions. The method is a reliable, sensitive and less time-consuming bioassay method [2,12,[15][16][17]72,73]. It has been used primarily for the screening of medicinal plants [2,[12][13][14]68].…”

“…The means (M), standard deviations (SD) and the standard deviations variances (SDV) using bell curve for Microsoft Excel by a special program (from Social Survey Research Information Co. Ltd) were calculated. The concept of the SDV, which has been used by previous studies [2,[12][13][14]16,17,72], was applied for the evaluation of allelopathic activity among samples. The criterion of SDV was estimated for the range of significant effects of the species.…”

“…The sandwich method was developed to determine the allelopathic activity through plant leachates [2,12] and has been widely used [2,[12][13][14]. The method is reliable and less time-consuming under laboratory conditions that could be used in extensive screening in the identification of potential allelopathic species [2,12,[15][16][17]. This study focused on medicinal plants from Turkey, which is one of the countries with the richest plant diversity in the Mediterranean region [18,19].…”