Allelopathy in wheat (Triticum aestivum)

Abstract

SummaryWheat (Triticum aestivum) allelopathy has potential for the management of weeds, pests and diseases. Both wheat residue allelopathy and wheat seedling allelopathy can be exploited for managing weeds, including resistant biotypes. Wheat varieties differ in allelopathic potential against weeds, indicating that selection of allelopathic varieties might be a useful strategy in integrated weed management. Several categories of allelochemicals for wheat allelopathy have been identified, namely, phenolic acids, hydroxamic acids and short‐chain fatty acids. Wheat allelopathic activity is genetically controlled and a multigenic model has been proposed. Research is underway to identify genetic markers associated with wheat allelopathy. Once allelopathic genes have been located, a breeding programme could be initiated to transfer the genes into modern varieties for weed suppression. The negative impacts of wheat autotoxicity on agricultural production systems have also been identified when wheat straws are retained on the soil surface for conservation farming purposes. A management package to avoid such deleterious effects is discussed. Wheat allelopathy requires further study in order to maximise its allelopathic potential for the control of weeds, pests and diseases, and to minimise its detrimental effects on the growth of wheat and other crops.

Evaluation of allelopathic potential of safflower genotypes (Carthamus tinctorius L.)

“…According to his results, safflower stem extract showed lower inhibitory effects on seed germination and root and shoot length of wild barley than leaf and root. Wu et al (2000bWu et al ( , 2001) also reported that allelochemicals are differently distributed in wheat with roots having a much higher level of allelochemicals than the stem. According to the findings of Nimbal et al (1996), Czarnota et al (2003) and Yang et al (2004), sorgoleone, an allelochemical of sorghum, constituted more than 80% of root exudate composition but none was found in immature and mature leaves and stems of sorghum.…”

Efecto alelopático de extractos acuosos foliares de diez ecotipos de trigo (Triticum aestivum L.) sobre Rumex acetosella L.

“…Tanto la planta como sus residuos pueden ser aprovechados para el manejo de la vegetación no deseada (Wu et al, 2001a). Estos compuestos alelopáticos denominados aleloquímicos se definen como sustancias químicas inhibitorias o fitotóxicas liberadas activamente por las plantas a través de diversas vías (Kogan, 1992;Ormeño, 1997) como son volatilización (principalmente desde hojas), lixiviación (desde follaje o raíces, por medio de lluvia, rocío o niebla), exudación (a través de las raíces) y descomposición de la materia orgánica por microorganismos (Ormeño, 1997;An et al, 1998;Wu et al, 1999;.…”

Wheat Herbage Amendments Alter Emergence Dynamics, Seedling Growth of Lambsquarter and Soil Properties

“…Numerous phytotoxic compounds or allelochemicals produced by wheat are phenolic acids, hydroximic acid, and short and long chain fatty acids (Wu et al, 2001;Ma, 2005). These compounds are phytotoxic for weeds as well as other crop plants (Wu et al, 2001). Allelopathic potential varies among cultivars of the same species (Anjum & Bajwa, 2010), plant parts (Qasem & Foy, 2001), and also with plant age (Wu et al, 2000), and phenological and environmental conditions (Rice, 1984).…”

“…Numerous phytotoxic compounds or allelochemicals produced by wheat are phenolic acids, hydroximic acid, and short and long chain fatty acids (Wu et al, 2001;Ma, 2005). These compounds are phytotoxic for weeds as well as other crop plants (Wu et al, 2001).…”