Phytotoxic effects of Euphorbia dracunculoides: a weed of rainfed chickpea-chickpea cropping system

Abstract

Phytotoxic effect occurs when plants release chemicals that inhibit neighoubouring plants. Phytotoxic effects of aqueous extracts of different parts of Euphorbia dracunculoides L. (green spurge) at two concentrations, and its infested soil were investigated on germination and seedling growth of chickpea (Cicer arietinum L.). The fruit extract at 1:20 (w/v) concentration caused maximum reduction (12%) in germination of chickpea seeds while leaf extract at 1:10 (w/v) concentration resulted in maximum mean germination time value and minimum germination index of chickpea seeds. All the traits of chickpea seedling growth including emergence were adversely affected by the aqueous extracts at both concentrations. Further, the inhibition of chickpea seedling growth was more pronounced with 1:10 (w/v) concentration whereas the lower concentration (1:20 w/v) showed stimulatory effect on shoot length, seedling vigor index and chlorophyll contents of chickpea seedlings. The leaf extract at 1:10 (w/v) concentration proved most harmful to seedling growth and chlorophyll contents (76% reduction) of chickpea. Soil beneath the E. dracunculoides plants significantly reduced emergence (23%), seedling vigor index (55%) and chlorophyll content (19%) of chickpea but a significant increase in N (6%), P (16%) and K (4%) contents of chickpea seedlings was recorded. Thus it can be concluded that E. dracunculoides contains compounds in its tissues which may cause phytotoxic effects on chickpea under field conditions. Additional key words: Cicer arietinum; emergence; germination; green spurge; phytotoxicity; seedling growth. ResumenEfectos fitotóxicos de Euphorbia dracunculoides, una mala hierba del sistema de cultivo garbanzo-garbanzo de secanoSe produce un efecto fitotóxico cuando las plantas liberan sustancias químicas que producen inhibiciones en las plantas próximas. Utilizando extractos acuosos a dos diferentes concentraciones de distintas partes de Euphorbia dracunculoides L., así como del suelo infestado, se investigaron sus efectos fitotóxicos sobre la germinación y crecimiento de plántulas de garbanzo (Cicer arietinum L.). Extractos del fruto 1:20 (p/v) provocaron la máxima reducción (12%) en la germinación de las semillas de garbanzo, mientras que extractos de hoja 1:10 dieron el máximo valor del tiempo medio de germinación y el mínimo en el índice de germinación. Todos los caracteres de crecimiento de las plántulas de garbanzo, incluyendo la emergencia, fueron perjudicados por los extractos acuosos a ambas concentraciones. Además, la concentración 1:10 inhibió el crecimiento de las plántulas de garbanzo de forma más pronunciada, mientras que la 1:20 mostró un efecto estimulante sobre la longitud de brotes y el índice de vigor y contenido de clorofila de las plántulas de garbanzo. El extracto de hoja 1:10 resultó más perjudicial para el crecimiento de plántulas y el contenido de clorofila (76% de reducción). Suelo extraído debajo de las plantas de E. dracunculoides redujo significativamente la emergencia (23%), el índice...

Response of Some Plant Species Towards the Allelopathy of Two Types of Chickpea (Cicer Arietinum L.) Seed Extracts

“…The maximum reduction in germination percentage of plant species at 4.00 mg/ml concentration could be due to more inhibitory effect of phytotoxic or allelochemicals present in seeds. An indirect relationship between a minor germination percent and allelopathic inhibition may be the consequence of alteration in the water uptake and synthesis of gibberellic acid, which regulates de novo amylase production during seed germination (Tawaha and Turk, 2003;Shanee et al, 2011;Muzell Trezzi et al, 2016;Tahir et al, 2018).…”

“…The significant decreasing in shoot and root elongation of plant species seedlings by different concentrations of seed extracts could be caused by the presence of ethanol soluble inhibitors (Yun and Kil, 1992;Shanee et al, 2011). These inhibitors include numerous substances like phenolic, terpenoids, organic acids, or alkaloids and essential compounds which act as allelochemicals and influence germination and seedling growth.…”

Germination Ecology of Two Troublesome Weeds of Arid Chickpea: Euphorbia dracunculoides and Astragalus Species

“…It is usually 15-40 cm tall and its stem is often much branched from the base (Wang et al, 2014). This species has been reported in cultivated and sandy fields of Pakistan, Egypt, Iraq, Kuwait, Saudi Arabia, Afghanistan, India, and tropical Africa (Shanee et al, 2011). Euphorbia dracunculoides density of 40 plants m -2 can cause chickpea grain yield losses by up to 63% (Tanveer et al, 2015).…”

“…Euphorbia dracunculoides has been previously studied for its phytotoxicity (Shanee et al, 2011). However, those studies did not address the germination ecology of E. dracunculoides.…”

Implications of weeds of genus euphorbia for crop production: a review

“…To date, more than 60 C 4 species have been detected within the genus (Downtown, 1975;Raghavendra & Das, 1978), and 18 species have been reported to have CAM physiology (Szarek, 1979). The extensively investigated species of Euphorbia includes Euphorbia dentata (toothed spurge) in corn, soybean and sunflower (Juan et al, 1996; E. esula (leafy spurge) in range and recreational lands (Dunn, 1979;Steenhagen & Zimdahl, 1979;Singh et al, 2000), monocrop land habitats (Selleck et al, 1962); E. dracunculoides (dragon spurge) in wheat, chickpea and mustard (Singh et al, 1995;Ponia et al, 1997;Shanee et al, 2011); E. geniculata ( painted spurge) in orchards of loquat, mango, guava, citrus group, grapes and ber (Zizyphus jajuba) (Sindhu & Bir, 1987), soybean and chickpea (Jain & Tiwari, 1993;Mishra & Singh, 2003); E. granulata (prostrate spurge) in lawn, cultivated field, onion (Hussain, 1980;Sadaqa et al, 2010); E. helioscopia (sunspurge) in wheat, lentil, chickpea, potato and pea (Ghafoor & Shad, 1990;Tanveer et al, 2010;Bharat & Kachroo, 2007 and as a medicinal plant (Jiangbo et al, 2010); E. heterophylla (wild poinsettia or painted spurge) in Kersting's ground bean (Macrotyloma geocarpa), soybean, cowpea, cotton, sugarcane, peanut (Harger & Naster, 1980;Akobundu & Agyaka, 1987;Eniola & Fawusi, 1989;Adelusi & Akamo, 2006); E. hierosolymitana (spurge) in wheat, orchards (Romman et al, 2010); E. hirta (Pill-bearing spurge) in rice -mung+sesame system (Ramanjaneyulu et al, 2006); chilli, maize, mustard (B. juncea) (Sandhu et al, 1999;Rajput et al, 2003;Singh & Agarwal, 2004;Kumar et al, 2009;…”