Weedy rice (Oryza sativa f. spontanea) problems and management in wet direct-seeded rice (O. sativa L.) in the Mekong Delta of Vietnam

Managing Water and Soils to Achieve Adaptation and Reduce Methane Emissions and Arsenic Contamination in Asian Rice Production

“…Direct seeding of rice has been practiced for many years in the Mekong Delta of Vietnam, where farmers appreciate the smaller labor requirement, the shorter time required to establish the rice crop, and the smaller water requirement, in comparison with transplanting seedlings from a nursery [222]. In a survey of 102 farm households in three districts of Can Tho Province, participants reported grain yields ranging from 6270 to 7310 kg per ha in 2012 and from 6790 to 8850 kg per ha in 2013, with profits ranging from USD 658 to 1184 per ha in 2012 and from USD 758 to 1268 per ha in 2013, on direct seeded rice fields [222].…”

“…In a survey of 102 farm households in three districts of Can Tho Province, participants reported grain yields ranging from 6270 to 7310 kg per ha in 2012 and from 6790 to 8850 kg per ha in 2013, with profits ranging from USD 658 to 1184 per ha in 2012 and from USD 758 to 1268 per ha in 2013, on direct seeded rice fields [222]. Managing weeds is a time consuming and costly effort when seeding the fields directly, but the yields and profits reported in the survey are among the highest observed in Asian rice production settings [222]. Weed management strategies include manual and mechanical weeding, the use of herbicides, and rotating herbicides with manual or mechanical weeding [223].…”

Economic Benefits of Controlling Red Rice: A Case Study of the United States

“…At current yield growth rates, only a 42% expansion in the supply of rice, a staple food for more than half of the world's population, is possible-instead of the 100% expansion needed to meet the projected demand by 2050 [4]. Compounding the problem, producers in Asia, where 90% of the global rice production occurs, are shifting away from transplanting rice to direct seeding [8,9]. This shift in production systems eliminates the weed suppression advantages of transplanted rice and exposes rice producers to potentially higher yield losses due to weed competition from red rice, in particular.…”

Reducing Herbicide Use Through Cropping System Diversification: A Case Study at the Iowa State University Marsden Farm, and Some Recommendations for the Mekong Delta of Vietnam

“…However, direct seeding techniques applied in the region provide a better environment for weed growth than do transplanting techniques (Dung and Dung, 1999). The most commonly applied weed control approach in the Mekong Delta is herbicides and the next most popular means is handweeding (Chauhan et al, 2015). Even though weed resistance to herbicides in rice in Vietnam has not been well documented (Azmi et al, 2005;Khanh et al, 2006), the current rice farming intensity and associated management practices are likely to result in a similar profile of weed resistance to herbicides in the Mekong Delta as has been noted in other rice-based regions in…”

“…Given the available weed management methods such as chemical and mechanical tactics and crop rotation (Chauhan et al, 2015), and current socio-economic context (Ives, 2013;Paris et al, 2009), weed control in the Mekong Delta region is likely to become more dependent on herbicides. Hand-weeding is five times more expensive than herbicide spraying in Vietnam (Moody, 1992).…”