Phytotoxic Activity of Parthenium Against Wheat and Canola Differ With Plant Parts and Bioassays Techniques

Abstract

-Phytotoxic effects of invasive weed Parthenium hysterophorus were studied by using whole plant, leaf and root aqueous extracts at 0, 2.5, 5.0, 7.5 and 10% (w/v) concentrations against germination and early seedling growth of wheat and canola. Studies were carried out both in Petri plates with filter paper as substratum placed in controlled conditions and soil-filled plastic pots placed in open environments. Pronounced variation was noted for phytotoxic activity of different plant parts of parthenium, aqueous extract concentrations, test species, and bioassay techniques. Aqueous parthenium extracts either inhibited or delayed the germination and suppressed seedling growth of test species over control. For both test species, all the germination attributes were suppressed to a greater extent in Petri plates than in plastic pots. Leaf extracts were more suppressive to germination of test species than whole plant and root extracts. Increasing extract concentration beyond 2.5% caused significant reduction in seedling dry biomass of both test species. Aqueous parthenium extract diminished chlorophyll contents of wheat and canola by 32-63% and 29-69%, respectively. Nevertheless, an increase of 9-172% and 22-60% in phenolic contents of wheat and canola was recorded. Canola appeared to be more susceptible than wheat at all extract concentrations. Present study concluded that bioassays conducted under controlled condition using filter paper as substratum may be misleading due to over estimation of allelopathic response and variation in potential of receiver and donor species. Furthermore, it implies that threshold concentrations of allelochemicals for test species in Petri plates are rarely reached under field conditions. Keywords: allelopathic inhibition, aqueous extracts, bioassay techniques, germination dynamics, parthenium, phenolics, seedling growth. Palavras-chave: inibição alelopática, extratos aquosos, técnicas de bioensaios, dinâmica de germinação, parthenium, compostos fenólicos, crescimento de plântulas. RESUMO -Foram estudados os efeitos fitotóxicos da planta daninha invasora

Allelopathic Effect of Parthenium hysterophorus on Germination and Growth of Some Important Crops and Weeds of Economic Importance

“…The results revealed that C. arietinum was more prone to the higher concentration of parthenium extract. Species-specific difference in sensitivity to aqueous leaf extracts of fresh and dry leaf material of P. hysterophorus was reported in previous studies (Meirse et al, 1987;Khaliq et al, 2016). The results indicated that areas highly infested with parthenium can accumulate a greater amount of allelochemicals and, thus, can pose harmful effects for wheat and other crops (Khaliq et al, 2016).…”

Evaluating Slow Pyrolysis of Parthenium hysterophorus Biochar: Perspectives to Acidic Soil Amelioration and Growth of Selected Wheat (Triticum aestivum) Varieties

“…Various studies have been conducted on the toxic effect of the P. hysterophorus on a wide range of crops. For instance, studies showed that extracts of the weed at lower concentrations (2.5–4%) significantly diminished seed germination, seedling biomass, and chlorophyll content of wheat by 60–75% [ 6 , 7 ] and grain yields of sorghum and maize by 40–97% and 30–60%, respectively [ 5 ]. However, different studies proposed that parthenium biochar can be used as green manure, compost, biocontrol, and soil amelioration that improve the soil physical, chemical, and biological properties and is a source of readily available plant micro- and macronutrients [ 8 – 10 ].…”

Inhibitory impact of Daraikh (Melia Azedarach) leaves litter on wheat (Triticum aestivum) seedling

“…al.Inhibitory Impact ofWhite Cedar… leavesproduce more allelochemicals which may prove lethal to economic crops. Khaliq et al (2016)…”