Growth ofEchinochloa glabrescensin Response to Rice Cultivar and Density

Abstract

In Asia, Echinochloa glabrescens is one of the most common Echinochloa species in rice production systems. The use of weedcompetitive rice ( Oryza sativa L.) cultivars and rice density are important components of integrated weed management tools, but their use requires understanding the extent to which rice can interfere with E. glabrescens growth and how the weed may respond to this interference. Growth of E. glabrescens was studied in a screenhouse by growing it alone and with 4, 8, and 16 plants of two rice cultivars (Rc222 and Sabita). Sabita was taller than Rc222, but Rc222 had greater biomass than Sabita. E. glabrescens produced greater shoot biomass and seeds plant −1 when grown with Sabita than with Rc222. Increases in rice density progressively reduced the number of leaves, leaf area, shoot biomass, and seed production of E. glabrescens. However, E. glabrescens grown with the highest rice density responded with increased leaf weight ratio, leaf area ratio, and specific stem length. Despite such plasticity, E. glabrescens shoot biomass and seed production decreased by 83% and 88%, respectively, when grown with 16 rice plants (approximately 80 kg seed ha −1 ) compared with its biomass and seed production without crop interference. The results suggest that rice interference alone may significantly reduce the growth of E. glabrescens but may not provide complete control. This highlights the need to integrate different weed management strategies to achieve complete control of E. glabrescens and other weeds in direct-seeded rice systems.

Lowland ecotype Cyperus rotundus L. affects growth and yield of rice under flooded conditions in the Philippines

“…[44]; Echinochloa glabrescens Munro ex Hook. f. [45]; and Amaranthus spinosus L. as well as Ludwigia octovalvis (Jacq.) Raven [46].…”

Assessment of Nitrogen Sources and Management for Sustainable Nitrogen Use in Subtropical Conditions: A Varietal Performance Study on Rice and Weed Growth

“…One of the most significant pests is weed, which cut grain yield in aus rice by 70-80%, transplant aman rice by 30-40%, and boro rice by 22-36% [9]. It was discovered that when nitrogen rates increased, Echinochloa crus-galli's growth and seed production also did so, which reduced the amount of nitrogen available to rice plants [10]. As a result, effective nitrogen management is crucial for determining how nitrogen affects the behavior of weed infestations as well as the development and productivity of rice.…”

Effect of Nitrogen on Weed Infestation and Performance of Boro Rice Under Two Selected Herbicides

“…However, both weed and rice plants compete for nitrogen and in a weed infested field weeds uptake N more rapidly than rice plant, particularly at high nitrogen levels (Nyarko and De Datta., 1993). It was found that, growth and seed production of E. crussgalli increases with increases in nitrogen rate resulting lesser nitrogen availability to the rice plants (Chauhan and Abugho, 2013). Therefore, proper herbicide and dose of nitrogen fertilizer are both critical factors for efficacy in weed management as well as growth and productivity of rice.…”