Germination Ecology of Chinese Sprangletop (Leptochloa chinensis) in the Philippines

Abstract

Chinese sprangletop is a grass weed that has the ability to grow in both flooded and upland conditions, which makes it a widespread and abundant weed in rice and many other crops. Experiments were conducted to study the germination of this weed in the Philippines. Germination was strongly stimulated by light and warm fluctuating temperatures, suggesting high emergence of Chinese sprangletop on bare ground such as a crop seedbed. A high level of germination (95%) immediately after seed harvest suggests that the soil seed bank of this species could be depleted by stale-seedbed strategies. Seed burial depth in soil strongly influenced emergence of this weed, and no seedlings emerged from seeds buried at depths of ≥ 0.5 cm. Maximum emergence (80%) from seeds placed on the soil surface suggests that no-till practices would enhance the emergence of seedlings. Seedling emergence from surface-sown seeds was similar (80 to 82%) between saturated and aerobic-moist soil, demonstrating that this weed does not require a saturated soil and that it can emerge from a moist soil. Flooding, even though not continuous or deep, had a suppressive effect on the emergence and dry matter of Chinese sprangletop. Germination responses to light and seed burial depth were different between our study in the Philippines and the study conducted with seeds of an Italian population, suggesting that Chinese sprangletop might be polymorphic. The implications of this information for weed management strategies are discussed.

Effect of different constant and alternative temperatures and light situations on germination behavior of two Purslane (Protulaca oleracea L.) populations

“…For example, Macdonald et al perceived Eupatorium capillifolium seeds are intensively photoblastic and neither of them germinated in darkness; whereas Eupatorium compositifolium seeds were moderately photoblastic and germinated about 12% in the darkness. Also the two broadleaf and tropical species of Corchorus olitorius and Melochia concatenate do not response to light treatments reported by [4]. According to result, the different light/dark periods effect on germination rate showed, the lowest germination rate between Karaj and Ahvaz population under the permanent darkness (0/24), which statistically was no significant difference between two populations ( Figure 6).…”

“…Seed germination is the main factor to thrive weed in the ecological niche, because it is the initial stage for weeds competition [2]. Furthermore seedling establishment is the sensitive point in plants life cycle and the first stage of this cycle is germination, which has determinant role on seedling establishment and development in ecosystem [3,4]. Germination is the consequence of complex interactions between some interior and exterior factors [5].…”

Global Warming and Its Possible Impact on Agriculture in India

“…Interference from C. album caused a reduction in soybean seed yield relative to the weed-free conditions; the reduction increased from 28% to 39% as CO 2 concentration increased. Flooding is commonly the primary cultural means to suppress weeds in rice as water depths of a few centimeters can suppress germination and emergence of a majority of weeds in rice (Chauhan, 2012a;Chauhan and Johnson, 2008, b, 2010. Conversely, with A. retroflexus interference, soybean seed yield losses decreased with increasing CO 2 from Table 2.23 Effect of CO 2 concentration on dry biomass of corn, Rottboellia cochinchinensis, soybean, and Abutilon theophrasti harvested at 12, 24, and 45 days after planting (Patterson and Flint, 1980) 45% to 30%, with no change in the mean biomass of A. retroflexus.…”

Rice Husk Biochar Influences Seedling Emergence of Junglerice (<i>Echinochloa colona</i>) and Herbicide Efficacy

“…Because of small seed size, seedlings of some seeds, for example, Chinese sprangletop [Leptochloa chinensis (L.) Nees] and ludwigia [Ludwigia hyssopifolia (G. Don) Exell. ], may not be able to emerge from a burial depth of 0.5 cm [17][18][19]. However, the addition of biochar to soils may decrease soil compaction and these weed species may easily emerge from such burial depths.…”