Abstract
Two field experiments were conducted to investigate rice-weed competition during direct-seeded rice cultivation. A rectangular hyperbolic equation was used to predict rice yield as a function of weed densities. Economic thresholds (ET) of multi-species weeds were estimated considering the cost of weed control and price of rice yield. The dry matter production and intraspecific competition of weeds were 1.13–3.63 g plant−1 and 0.0375–0.0383, respectively. The competition effect of weeds on rice was significant and the competitivity value ranged from 0.0170 to 0.0126. Therefore, the number of panicles m−2, grains panicle−1 and 1,000-grain weight were significantly reduced by the competition of weed species. Considering the weed competitivity, weed control costs and price of grain, the ET values of weeds were 4.72–9.17 plants m−2. These findings will be useful for weed management in direct-seeded rice cultivation.
Highlights
Rice (Oryza sativa L.) is an important staple food in Asia
Because weed and rice seedlings emerge simultaneously and there is no standing water to suppress weeds at the time of crop emergence [1], weed control is an essential and important component of rice production because uncontrolled weeds can lead to rice yield losses as high as 80 % [16]
The infesting weed species belonged to 6 families and 11 genera
Summary
Rice (Oryza sativa L.) is an important staple food in Asia. Growers in many Asian countries (e.g. the Philippines, Bangladesh and India) are shifting their production system from traditional puddle-transplanting rice to direct-seeded rice [3]. Direct-seeded rice (DSR) has several advantages such as being labor intensive and consuming less water [2], but weeds are the main biological constraint in this system. Because weed and rice seedlings emerge simultaneously and there is no standing water to suppress weeds at the time of crop emergence [1], weed control is an essential and important component of rice production because uncontrolled weeds can lead to rice yield losses as high as 80 % [16]. An empirical model of the impact of weed interference on crop yield
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
