Stakeholder and field surveys on weed issues and research needs in rice production in Texas

Abstract

A paper-based survey was conducted from 2015 to 2017 among stakeholders of the Texas rice industry on current weed management challenges and factors influencing management decisions. A total of 108 survey questionnaires were completed by stakeholders at the rice extension meetings conducted in the rice-growing counties of Texas. Additionally, late-season field surveys were conducted prior to harvest in 2015 and 2016 across the rice-growing counties to understand dominant weed escapes occurring in rice fields. Results from the questionnaire survey revealed that rice-fallow-rice was the most common rotation practiced in Texas rice production. Echinochloa spp., Leptochloa spp. and Cyperus spp. were the top three problematic weed issues faced by the respondents. Among the Leptochloa spp., Nealley’s sprangletop, a relatively new species in rice fields, was indicated as an emerging concern. Clomazone was the most frequently used PRE herbicide, whereas quinclorac, propanil, imazethapyr and cyhalofop were the popular POST herbicides. Most respondents (72%) made weed control decisions based on economic thresholds, whereas 63% made decisions based on weed problems from previous years. Eighty-eight percent of respondents expressed moderate to high concern for herbicide-resistant weeds in their operations. Strategies to manage herbicide-resistant weeds and economical weed management practices were among the top suggested research needs. The field survey revealed that junglerice, Nealley’s sprangletop, and hemp sesbania were the top three late-season weed escapes in rice production in Texas, with a frequency of occurrence of 65, 43, and 31%, respectively. Furthermore, average field area infested by a species was the greatest for junglerice (13% area), followed by hemp sesbania (11%) and weedy rice (11%). Findings from the stakeholder and field surveys help direct future research and outreach efforts for sustainable weed management in Texas rice culture.

Echinochloa in mid-southern U.S. and California rice: What is known and what are the knowledge gaps?

“…Nonetheless, it is well recognized that in glyphosate-based cropping systems weed spectrums will adapt or vary in response to changes in production methods or new technologies, especially in crop fields where yearly monoculture is frequently the goal (Reddy and Norsworthy 2010; Webster and Coble 1997; Webster and Sosnoskie 2010), favoring the perpetuation of one or several weed species, including those that have evolved the ability to escape herbicide applications (Norsworthy et al 2013). This observation in mid-South rice may be attributed to the higher prevalence of herbicide resistance in junglerice, as reported by Rouse et al (2018) in Arkansas and by Lui et al (2021) in Texas. It may also reflect its proliferation in the continuous dry seeding and delayed flooding rice culture, as well as the rice-soybean production system practiced in the region, or a combination of all these factors.…”

“…Several anomalous reports in recent years (Lui et al 2021, 2022; Rouse et al 2018; Tahir and Roma-Burgos 2021; Wu et al 2022) raise the question of whether junglerice has become more established than was previously believed in mid-South rice fields, even to the extent that it has indeed surpassed barnyardgrass. The greater representation of junglerice than barnyardgrass in the samples analyzed does not necessarily indicate the greater relative abundance of junglerice.…”

Grass-weed challenges, herbicide resistance status and weed control practices across crop establishment systems in Ireland’s mild Atlantic climate

“…The weed score results based on grid-sampling are presented on a map, on an establishment system basis, for the key grassweed species encountered (Figure 2A). A separate historical Liu et al, (2020), where the first, second, third, fourth and fifth most difficult-to-control species specified by each grower are assigned values of 5, 4, 3, 2 and 1, respectively and summing their values. b Frequency counts calculated as number of farms with grass weeds versus total participating farms (n= 103).…”

“…While grower surveys focusing on problem weeds, weed pressure, resistance awareness and weed control practices have been conducted in the UK, USA, Australia, or elsewhere (e.g. Johnson and Gibson, 2006;Lewellyn et al, 2007;Riemens et al, 2010;Ulber and Rissel, 2018;Hicks et al, 2018;Liu et al, 2020), no such research has been carried out in the Atlanticinfluenced Irish production conditions.…”

Morphophysiological diversity and its association with herbicide resistance in Echinochloa ecotypes

“…More details of the survey methodology can be found in Liu et al (2020). A total of 232 fields were surveyed, but samples were collected only in fields where the Echinochloa escapes were present.…”