Potential of Aqueous Extracts from Parts of the Pepper Tree (Schinus molle L.) to Affect Emergence and Seedling Development of Wheat (Triticum sativa L.) and Weeds in a Manure Amended Soil~!2008-09-12~!2008-11-15~!2008-12-05~!

Abstract

Abstract:The allelopathic potential of aqueous extracts from fruits, leaves, roots and bark of the pepper tree (Schinus molle L.) were investigated on emergence and seedling development of wheat (Triticum sativa L.) and agricultural weeds. Different concentrations of the original extract (undiluted, 1:1, 1:3 and water, v/v) were applied to a soil amended with cattle manure in 2-litre pots. Extracts from all the tree parts significantly (p < 0.05) reduced seedling emergence, height and dry matter yields of wheat and weed seedlings compared to the control (water). The inhibitory effects on both wheat and weed seedlings were consistently in the order fruit=leaves >roots>bark. The inhibitory effects were however progressively reduced by diluting the original extracts suggesting that there was reduction in the concentration of the compounds inhibiting the emergence and development of seedlings.The weed population and species composition were negatively affected by tree extracts but improved with dilution of the extracts. It was observed that grass weed species were relatively more adversely affected by the inhibitory compounds in the extracts than broad leaf species at each level of extract dilution. The results confirm the presence of water-soluble compounds in the tissues of the pepper tree which can inhibit seedling emergence and growth of wheat and weed seedlings. It is concluded that the pepper tree posses allelopathic characteristics that may be explored for weed management in agriculture. Further investigations are recommended to elucidate the nature of the phytotoxin, formulation, mode of application and the appropriate economic way of exploiting this potential.

Differential allelopathy between genders of an invasive dioecious tree on desert plants

“…Blends were later filtered and the resulting extracts were used in the germination trials described below. This procedure concurs with those used by other authors that have assessed the allelopathic effects of peppertrees on crops (Materechera and Hae, 2008;Borella et al 2011). Nevertheless, since the inhibitory effects of allelopathic compounds usually depend upon their concentrations (Batish et al, 2002;Materechera and Hae, 2008), a fraction of the extracts was diluted to the half of its original concentration.…”

“…This procedure concurs with those used by other authors that have assessed the allelopathic effects of peppertrees on crops (Materechera and Hae, 2008;Borella et al 2011). Nevertheless, since the inhibitory effects of allelopathic compounds usually depend upon their concentrations (Batish et al, 2002;Materechera and Hae, 2008), a fraction of the extracts was diluted to the half of its original concentration. Thus, for each plant organ we obtained a concentrated extract equivalent to 100 g of plant organs per liter of distilled water, and a diluted extract equivalent 50 g of plant organs per liter of distilled water.…”

“…However, as far as we are aware, these negative effects on crop germination have been only evaluated for fruits and leaves produced by female peppertrees (Anaya and Gomez-Pompa, 1971;Materechera and Hae, 2008;Zahed et al, 2010;Barroso et al, 2011), while the allelopathic potential of male individuals have not received much attention. Therefore, the allelopathic effects of peppertrees on Mexican succulent plants remain unknown, as well as the differential effects that male and female trees may have on these species.…”

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“…The use of allelochemicals by allelopathic plants/plant parts for weed management has received attention in recent times (Weston 1996) in view of their environmental friendly nature as opposed to synthetic chemicals. Hence the use of natural substances from plants is considered as a low input and sustainable approach to integrated weed management, a practice that helps reduce the increasing incidences of herbicide resistance in weeds as well (Mayer & Mayber 1989, Materechera & Hae 2008.…”

“…The allelopathic and herbicidal effectiveness of different plant species have shown to depend on the plant part (Oudhia 2003). Therefore investigations are required to explore plants and respective plant parts with effective allelopathic activity, especially in the control of agricultural weeds (Materechera & Hae 2008). The inhibitory effects of extracts obtained from different seed pericarps and plant parts on seed germination of Fonseka et al (2017) Humaid & Warrag (1999), Kivi et al (2010).…”