Germination ecology of wild onion: a rainfed crop weed

Abstract

-Asphodelus tenuifolius is becoming a more common weed in rain-fed area in Pakistan. Laboratory and greenhouse experiments were conducted to determine the effect of different environmental factors on germination and emergence of A. tenuifolius. Results showed that A. tenuifolius can tolerate a wide range of varying environmental factors. Greatest percentage of germination (80%) was recorded at 15 o C constant temperature; however, considerable germination occurred at 20 and 25 o C. Light for 10 h photoperiod stimulate germination of Asphodelus tenuifolius compared with complete darkness. Germination was totally inhibited at osmotic stress higher than -0.8 MPa. There was no significant difference in germination at pH 6 to 8; however, there was a slightly decrease at pH 9, compared with distilled water. Asphodelus tenuifolius was very sensitive to salinity; however, a few seeds of A. tenuifolius were able to germinate even at 150 mM NaCl concentration. Greatest emergence occurred with seed placed at soil surface and emergence decreased with increase in burial depth. No emergence occurred from 4 cm or greater. This information may aid in developing tools and strategies for management.Keywords: Asphodelus tenuifolius, temperature, water stress, salt stress, pH, seedling emergence, seeding depth. RESUMO -Asphodelus tenuifolius está se tornando uma planta daninha cada vez mais comum em plantio de sequeiro no Paquistão. Foram realizados experimentos no laboratório e na estufa para avaliar a influência de diferentes fatores ambientais na germinação e emergência da Palavras-chave:Asphodelus tenuifolius, temperatura, estresse hídrico, estresse salino, pH, emergência de plântulas, profundidade de semeadura.

Effect of environmental factors on the germination and emergence of Salvia verbenaca L. cultivars (verbenaca and vernalis): An invasive species in semi-arid and arid rangeland regions

“…verbenaca in the highest temperature range. By comparison with these two Salvia verbenaca varieties, some species are more dependent on light as a germination cue, e.g., Galenia pubescens [ 8 ] and Chenopodium album [ 12 ], whereas other species, e.g., Asphodelus tenuifolius are not significantly inhibited by a lack of light [ 13 ]. It is possible that the amount of light may also have an influence on the rate of germination [ 17 ], and whilst this phenomenon was not investigated in this study, it may be of interest for future research into these two S .…”

“…Some weeds have a narrow tolerance range, while others are able to germinate over a wide range of temperatures [ 10 ], [ 9 ]. Water stress may delay or prevent the germination of seeds [ 11 ], and the effect of drought on germination may vary according to weed species or between different populations of same weed [ 12 ], [ 13 ]. Salinity may affect seed germination according to species, genotypes and environmental conditions [ 14 ] and germination may be reduced when salt accumulation exceeds a threshold level [ 15 ], [ 16 ].…”

Germination Ecology of Lathyrus aphaca, a Problematic Weed of Wheat Crop under Semi-Arid Conditions of Pakistan

“…Seed germination/emergence of several weeds species continued without any effect of pH (4.0 to 9.0 pH) in different experiments (Thomas et al, 2006;Chachalis et al, 2008;Wang et al, 2009). Tanveer et al (2014) stated that there was no difference in germination percentage in wild onion (Asphodelus tenuifolius) seeds at pH levels of 6.0-7.5. Approximately 92% germination was recorded in Hyparrhenia hirta at 7.00 pH level, but at pH levels of 5.0 or 9.0, seed germination was reduced (10%) in (Chejara et al, 2008).…”

“…Burial depth or location of weed seeds in the soil seedbank significantly affects viability, germination and emergence (Bebawi et al, 2015). Seeds of green galenia (Galenia pubescens) and Asphodelus tenuifolius exhibited more germination when sown on the soil surface (Tanveer et al, 2014;Mahmood et al, 2016) while amaranthus species showed higher germination and emergence at 1 cm depth (Hao et al, 2017). Therefore, it is obvious that seed germination of different weed species or weed species in genera may respond differently to environmental factors.…”

Germination Ecology of Ivy-Leaved Morning-Glory: an Invasive Weed in Soybean Fields, Iran

“…Also, studying the ecology of seed germination of various species is very useful to recognize and explain plant evolution and ecological adaptation (Baskin et al, 2004). Biological and ecological information, specifically germination ecology of a specific weeds is necessary to develop long-term management strategies (Mennan and Ngouajio, 2006;Nakamura and Hossain, 2009;Ali et al, 2013;Tanveer et al, 2014). Peters et al (2000) reported that knowledge of the influence of environmental factors on the germination and emergence behavior of seeds would be helpful to prevent their invasion to new areas and determine its management practices.…”