Response of weedy rice (Oryzaspp.) germplasm from Arkansas to glyphosate, glufosinate, and flumioxazin

Abstract

Weedy rice (Oryzaspp.) is one of the most competitive weeds in rice (Oryza sativaL.) production. Rapid growth, high tillering, enhanced ability to uptake fertilizers, asynchronous maturation, seed shattering, and high seedbank longevity makeOryzaspp. more competitive than cultivated rice and highly persistent.Oryzaspp. may be a source of useful traits for crop improvement such as herbicide tolerance. Greenhouse studies were conducted to evaluate the response of 54Oryzaspp. accessions collected between 2008 and 2009 from Arkansas to glyphosate, glufosinate, and flumioxazin applied at field rates. Rice cultivars ‘CL163’ and ‘REX’ were included for comparison. Accessions B20, B2, and S11 and B49, B51, and S59 showed reduced sensitivity to glyphosate and flumioxazin, respectively. These accessions had less than 40% injury 5 wk after treatment (WAT). Rice cultivars (CL163 and REX) were sensitive to both glyphosate and flumioxazin, with more than 95% plant mortality at 5 WAT. On average, blackhull accessions were more tolerant to glyphosate and flumioxazin than strawhull accessions. Dose–response analysis of B20, B2, and S11 confirmed 3- to 8-fold higher tolerance of these accessions to glyphosate. AllOryzaspp. and cultivated rice were not affected by glufosinate applied at 874 g ai ha−1(1X) and were controlled 100% by 1,311 g ai ha−1(1.5X).Oryzaspp. lines with reduced sensitivity to glyphosate and flumioxazin will be studied further for use in rice crop improvement.

Relationship between weedy rice (Oryza sativa) infestation level and agronomic practices in Italian rice farms

“…The ordinal logistic regression underlined that the use of the stale seedbed practice was correlated with the O. sativa infestation, and the two-step cluster analysis showed that the surveyed farms were mainly grouped based on the application of this technique. The majority of the farms that adopted the stale seedbed practice were characterized by a higher O. sativa infestation level than those that did not use it, which means that this technique was mainly applied where there were more serious O. sativa infestations, due to its high efficacy (Shrestha et al 2019). The present study also highlighted that farmers in the Italian ricegrowing area surveyed often rely on the stale seedbed technique to control O. sativa, as well as on the use of imazamox coupled with Clearfield® rice varieties.…”

Crop Diversification for Improved Weed Management: A Review

“…Among the global herbicide-resistant weed cases, most were reported in the USA, followed by Australia, Canada, China, and Brazil [18]. In addition to this, some weeds have developed resistance to multiple modes of action while others have (developed decreased sensitivity to herbicides [21][22][23]. Both target-site and non-target-site mutations in the herbicide-resistant weeds have been reported [24,25].…”

Off-season management with herbicides as an alternative to reduce weed infestation in paddy rice production systems

“…The decision to increase the rate in the herbicides clomazone and oxyfluorfen was a successful practice, emphasizing that this decision was made because these herbicides were selective for waterseeded rice when used in smaller rates (Cavero et al, 2011;Agrofit, 2019). Similarly, Shrestha et al (2019) demonstrated that flumioxazin at a rate of 72 g ha -1 was effective in controlling 51 genotypes of weedy rice. The efficiency of S-metolachlor in the control of Oliveira Neto AM, Guerra N, and Noldin JA.…”