Agronomic implications of paraquat ban in Brazil

Abstract

Background

Paraquat is a broad spectrum herbicide used particularly in burndown, in pre-plant of row crops and in the pre-harvest desiccation of some crops. In Brazil, paraquat was re-evaluated by Anvisa, leading to a prohibition of production and sales on September 22, 2020, and used until July 31, 2021.

Objective

The objective of this review is to characterize the use of paraquat in Brazil and describe the status in other countries, particularly the agronomic implications of its ban, possible replacements, and scenarios.

Review

The use of paraquat is important for weed management in different production systems. Owing to its toxicity, its use has been re-evaluated in several countries. For pre-harvest desiccation of soybeans, diquat, glufosinate, and some combinations with Protox inhibitors are highlighted as alternatives to paraquat. For pre-harvest desiccation of common beans, diquat, saflufenacil, and glufosinate could be used; however, only glufosinate could be used for wheat. For managing broadleaves weeds, glufosinate, saflufenacil, carfentrazone, and diquat are effective alternatives. Diquat may be less effective in controlling Conyza spp. resistant to paraquat. For grasses control, glufosinate, in addition to ACCase inhibitors and possible mixtures, may be helpful. Although pre-emergent herbicides are not classified as desiccant herbicides, they contribute to weed management. The adoption of herbicide-tolerant crops, mechanical control, and cover crops can be added as agricultural practices for integrated weed management.

Conclusions

Due to the ban on paraquat, challenges arise, and the most often suggested replacements are glufosinate, diquat, and Protox inhibitors; however, grass control will be of greater concern.

Bipyridylium; weeds; pre-harvest; herbicides

1.Introduction

Paraquat is a non-selective, broad-spectrum, photosystem I electron diversion (group 22), which can be used in burndown applications (Zobiole et al., 2018; Kalsing et al. 2020), in the pre-harvest desiccation of some crops (Bellaloui et al., 2020; Pereira et al., 2020), in interrow application (Costa et al., 2013) and in non-agriculture areas (e.g., under electric transmission lines, railways, and roadsides). However, it has been banned in several countries (Camargo et al., 2020; Kim, Kim, 2020; Tsai, 2020).

Paraquat is highly toxic to mammals (Baltazar et al., 2013a) and has moderate to high acute oral toxicity, high acute inhalation toxicity, and low dermal toxicity. Moreover, it has severe ocular and moderate skin irritant potential (Kim, Kim, 2020). Once ingested, paraquat causes highly acute toxicity in humans, and survival depends on the amount consumed and the time until treatment begins (Gil et al., 2008). Studies have suggested an association between exposure to paraquat and Parkinson’s disease (Tamano et al., 2019; Tangamornsuksan et al., 2019). Given its toxicity, paraquat was used for suicide or attempted suicide in Asian countries such as South Korea and Taiwan. Due to the ban on the molecule in these countries, suicidal rates were reduced (Kim, Kim, 2020; Tsai, 2020). There is no specific antidote for paraquat poisoning (Kumar et al., 2016).

In Brazil, the Anvisa promote a re-evaluation of paraquat from 2008 to 2017 due to its high toxicity (Agência Nacional de Vigilância Sanitária, 2017). In 2017, after the review, paraquat was temporarily banned. Due to lack of alternatives for replacement of paraquat in the field, the decision was revised, and a usage restriction was issued from September 22, 2017, to September 22, 2020, when paraquat was permanently banned (Camargo et al., 2020). However, although with several restrictions, stocked paraquat use was allowed in the 2020/21 growing season (until July 31, 2021) (Agência Nacional de Vigilância Sanitária, 2020a).

As of September 22, 2020, with the ban on the production, commercialization, and the use of paraquat as of 2021, Brazil is experiencing a substantial agronomic impact due to the extensive use of paraquat in the production systems. Thus, this study aims to characterize the previous use of paraquat in Brazil, the situation in other countries, and particularly the agronomic implications of its ban in the country, possible replacements, and impact.

2.Paraquat: mode of action and historical aspects

Paraquat and diquat are bipyridylium herbicides with photosystem I electron diversion mode of action. They have contact action, limited translocation and rapid leaf absorption, with a broad spectrum of weed control (Bromilow, 2004; Rodrigues, Almeida, 2018). Herbicides in this group act as false electron acceptors in photosystem I, producing reactive oxygen species. Plant death occurs due to the destruction of fatty acids in thylakoids and other membranes by producing free radicals, which cause, necrosis, and finally, plant death. Symptoms can be observed within a few hours after application, under bright light conditions, and plant death can occur in up to one day (Bromilow, 2004; Hawkes et al., 2014). Paraquat has a high sorption coefficient (Koc) (Amondham et al., 2006; Muhamad et al., 2011). This strong bond significantly limits its bioavailability in the soil; therefore, it is not toxic to plant roots under normal application conditions, that help explain lack of effectiveness on weeds at pre-emergence. Although it is not bioavailable for roots in the soil, due to its high Koc, paraquat has a half-life of approximately six years (Pateiro-Moure et al., 2009) and with low degradation by microorganisms (Roberts et al., 2002). These aspects can prolong its persistence in the soil and contaminate other environments, such as water bodies (Huang et al., 2019). Regarding the vapor pressure, it has a negligible value at room temperature, practically non-volatile (Sartori, Vidrio, 2018).

Bipyridylium compounds were first recognized as herbicides in 1954 in the United Kingdom by the Imperial Chemical Industries (ICI) (Cronshey, 1961; Funderburk, Lawrence, 1964; Akhavein, Linscott, 1968). Diquat was the first to be discovered. In 1955, paraquat salts were also considered active. Paraquat, a known chemical since 1882, has been used since 1932 under the name of methyl viologen as an oxy-reduction indicator (Bromilow, 2004).

Paraquat was vital to establish the non-till system in agriculture, one of the primary conservation grain production systems. The non-till system was initially developed by ICI and partners, which involved paraquat and the use of special equipments to drill in non-tilled soils. No-till and paraquat were introduced in the United States in 1960, with the first reports of commercial use of no-till between 1962 and 1966 (Ekboir, 2003). In Brazil, the technology began to be tested in the 1970s, with the first experiments carried out in Londrina (state of Paraná) and Passo Fundo (state of Rio Grande do Sul), between and 1972-1974, using paraquat (Wiles, Hayward, 1981). After the first studies, between the end of the 1970s and the beginning of the 1980s, other herbicides, mainly glyphosate, were used, and paraquat use declined in no-till (Ekboir, 2003; Bolliger et al., 2006).

The development and adoption of the no-till system are essential for conserving soils in areas of grain crops in Brazil, generating agricultural, environmental, and social benefits (Freitas, Landers, 2014). Therefore, paraquat is of great importance to implement the system. In addition, the increase in the use of paraquat in pre-sown burndown application in the 1990s became one of the main uses of this herbicide. It is effective for weed control and desiccation of previous crops (Neves et al., 1999; Argenta et al., 2001).

With the adoption of transgenic crops tolerant to glyphosate, the consequent increase in the use of this herbicide, and its application in post-emergence on these crops, glyphosate-resistant weed biotypes have been observed. Thus, other herbicides have become even more critical to reduce the selection pressure for new resistant biotypes and for their control. Therefore, paraquat use increased for pre-sowing burndown of soybeans and other crops, as an alternative or combined with glyphosate, to control grasses such as Digitaria insularis (Marochi et al., 2018) and broadleaves such as Conyza spp. (Cesco et al., 2019), both of which can be resistant to glyphosate.

3.Overview of paraquat use in Brazil and other countries

As previously mentioned, paraquat was banned on September 22, 2020; however, products in stock could be used in the 2020/21 growing season, with restrictions (Agência Nacional de Vigilância Sanitária, 2020a). A total ban was implemented on July 31, 2021, and paraquat could not be used in any crop or region in Brazil.

Nowadays, paraquat is banned in more than 50 countries worldwide, including China, South Korea, the European Union, and the United Kingdom. In other countries such as the United States, Australia, Colombia, Chile, Uruguay, and Japan, paraquat is under re-evaluation and/or use in strictly controlled use (Baltazar et al., 2013b; Camargo et al., 2020; Kim, Kim, 2020; Tsai, 2020).

Paraquat was banned in South Korea in 2012. One of the reasons for the ban was many number of suicides by ingesting paraquat. The paraquat ban significantly impacted agricultural practices and was replaced mainly by glyphosate, glufosinate, and some Protox inhibitors. Although there was a reduction (46.1%) in the total number of suicides from pesticide ingestion (with the paraquat ban), there was an increase in suicide attempts with other pesticides (Kim, Kim, 2020) demonstrating the complexity of this topic.

In Sri Lanka, the most rigid restrictions on the use and import of paraquat were established in 2008, with a definitive ban in 2014 (Marambe, Herath, 2020). The decision to ban paraquat did not generate significant arguments because detailed studies were performed on its health risks, which led to this decision. Due to the restrictions, there has been a considerable increase in the use of glyphosate, which was banned in Sri Lanka in 2015. The ban on glyphosate in Sri Lanka has impacted agricultural practices and discussions. In contrast to paraquat, many researchers and farmers claim that the studies that led to the glyphosate ban were not scientifically proven and conclusive.

With the ban of paraquat in Brazil, it is necessary to understand the situations in which it is used, the implications of its prohibition, and alternatives to its use. In Brazil, paraquat is one of the most used pesticides. According to Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis – Ibama (2022), in 2019, paraquat was the seventh most commercialized pesticide (16,398.14 t active ingredient – a.i.) and the fourth most commercialized herbicide, behind atrazine, 2,4-D, and glyphosate, which was the most commercialized with 217,592.24. More than 10,000 tons of a.i. paraquat have been sold each year since 2015 until 2019, with an increase, particularly in recent years. In 2020, there was a lower sale of paraquat (8,120.21 t a.i.) since it was banned from 22 September. Further information on the pesticides sales in Brazil between 2011 and 2020, particularly paraquat, is presented in Table 1. These data reinforce the importance of paraquat in Brazilian agriculture; therefore, it becomes even more essential to characterize the use of paraquat in the country, the implications of its ban, and the alternatives for its replacement.

Table 1
Sales of pesticides, total of herbicide and paraquat in Brazil in the period 2011-2020.

Year	Pesticides	Herbicides	Paraquat
	tons (ai)	tons (ai)	tons (ai)	L (cp)*
2011	419,528.63	221,329.57	4,275.38	21,376.88
2012	476,554.86	298,872.07	5,249.54	26,247.69
2013	495,772.60	303,573.23	6,792.69	33,963.45
2014	508,556.84	294,915.53	8,404.76	42,023.79
2015	521,525.40	314,452.55	10,536.60	52,683.01
2016	541,861.09	322,755.10	11,638.19	58,190.94
2017	539,944.95	315,573.38	11,756.39	58,781.97
2018	549,280.44	338,838.14	13,199.97	65,999.84
2019	620,537.98	369,578.94	16,398.14	81,990.70
2020	685,745.68	413,833.41	8,120.21**	40,601.05**

• c.p.: commercial product
• * Estimate based on a concentration of 200 g ai L^-1.
• ** Ban of paraquat sales on 22 September 2020.
IBAMA (2022)

4.Pre-harvest desiccation

Paraquat is widely used for pre-harvest desiccation in various crops, such as cotton, rice, potatoes, sugarcane, maize, and soybeans (Rodrigues, Almeida, 2018; Ministério da Agricultura, Pecuária e Abastecimento, 2022). A complete list of crops with herbicides registered for pre-harvest desiccation are presented in Table 2. In this method of use, paraquat was applied at the physiological maturity of the crops (Rodrigues, Almeida, 2018), as it is a contact herbicide with very limited translocation, application at the appropriate stage ensures non-accumulation in food. The maximum residue limits, in mg kg^-1 of paraquat, was 0.5 for rice, 0.2 for cotton, potatoes, and 0.1 for sugarcane, maize, and soybeans, respectively (Agência Nacional de Vigilância Sanitária, 2020b).

Table 2
Herbicides registered in Brazil for application pre-harvest.

Herbicide	Crops with registration
Paraquat*	Cotton, rice, potato, sugarcane, maize, and soybean
Glufosinate	Potato, sugarcane, barley, peas, bean, chickpea, lentil, soybean, and wheat
Diquat	Potato, bean, and soybean
Saflufenacil	Cotton, potato, bean, sunflower, and soybean
Carfentrazone	Cotton and sugarcane
Flumioxazin	Bean and soybean

Rodrigues and Almeida (2018)
• * Banned on July 31, 2021.

Pre-harvest desiccation of soybeans can standardize plant maturity, predict harvest, control weeds, and minimize the loss in grain quality (Boudreaux, Griffin, 2011; Toledo et al., 2012; Lamego et al., 2013). In addition to paraquat, other herbicides have been used for this purpose. Some studies have reported the efficacy of glufosinate (Delgado et al., 2015), diquat (Finoto et al., 2017; Araújo et al. 2018), carfentrazone (Pereira et al., 2015), saflufenacil (Zuffo et al., 2020) and flumioxazin (Carvalho, 2017). Zagonel (2005) observed equivalent efficacies for the application of diquat (200 g a.i. ha^-1), paraquat (200 g a.i. ha^-1), and glufosinate (200 g a.i. ha^-1) for the desiccation of soybean without reducing yield. In addition, some combinations of glufosinate with protox-inhibiting herbicides, such as carfentrazone, flumioxazin, and saflufenacil, can be promising for pre-harvest desiccation in soybeans. For the use of protox-inhibiting herbicides in this modality, attention must be paid to the moment/stage of application, considering the growth habit of soybeans, avoiding the anticipation of products with pronounced and rapid contact effects.

Although paraquat has no registry for pre-harvest bean desiccation in Brazil, this herbicide was occasionally used for this purpose by farmers. The effectiveness of paraquat in this modality has been highlighted in several studies (Pinto et al., 2014; Goffnett et al., 2016). Saflufenacil has been evaluated in some studies; in general, it is a good defoliant; however, it can interfere with the quality of seeds or bean yield (Goffnett et al., 2016; Castoldi et al., 2019; Silva et al., 2020), requiring adequate positioning to achieve the expected performance. Other options for paraquat include glufosinate (Soltani et al., 2013; Goffnett et al., 2016; Castoldi et al., 2019), diquat (Soltani et al., 2013; McNaughton et al., 2015) and flumioxazin (Soltani et al., 2013). Therefore, diquat and glufosinate, particularly, should have increased in the pre-harvest desiccation of beans.

Paraquat has not been registered in Brazil for pre-harvest desiccation of wheat; however, the effectiveness of paraquat in pre-harvest desiccating of wheat has been observed in some studies (Krenchinski et al., 2017; Perboni et al., 2018). However, desiccation in this crop is a very complex treatment. The efficiency, quality of seeds, and productivity can be affected by the stage of application, herbicide, and cultivar, among other elements. Krenchinski et al. (2017) reported that reductions in wheat yield were found for desiccation with glufosinate, paraquat, glyphosate, clethodim, and diquat; only the carfentrazone did not reduce yield in both locations of the experiments.

Only glufosinate at a dose of 350 g a.i. ha^-1 has a registration for wheat desiccation (Rodrigues, Almeida, 2018; Ministério da Agricultura, Pecuária e Abastecimento, 2022). Other studies provide evidence of its potential safety. The application of glufosinate (400 g a.i. ha^-1) pre-harvest, at the milky to soft dough grain, soft dough to hard dough grain, or hard grain did not reduce wheat yield, even without any residue in grains for application in the hard grain stage (Perboni et al., 2018). Thus, this herbicide will continue to be used to manage pre-harvest desiccation in wheat to achieve standardization objectives, weed control, quality improvement, and reduction of yield losses.

Among the other crops in which pre-harvest desiccation is usual, the possible scenarios in potato crop (Solanum tuberosum) are worth mentioning. The herbicides glufosinate, saflufenacil, and diquat are effective for this purpose (Ferebee et al., 2019) and are registered in Brazil (Ministério da Agricultura, Pecuária e Abastecimento, 2022). These herbicides should be considered good alternatives to paraquat in the desiccation of potato plants.

5.Weed management

Paraquat is a contact herbicide that rapidly affects susceptible weeds and controls a broad spectrum of weeds. In the recent history of paraquat and Brazilian agriculture, the primary use of paraquat is in burndown on pre-sowing of several crops. In weed control, in advance of soybean, the main agricultural crop in Brazil, paraquat is predominantly used in applications immediately before or immediately after sowing soybeans. Paraquat is widely used in off-season management and is more used in the second or third sequential application. The last one before or immediately after sowing, it is used alone or combined with a pre-emergent herbicide (Figure 1). Table 3 presents the direct and possible substitutions in systems involving soybeans.

Figure 1
Exemplification of applications in burndown soybean pre-sowing.

Table 3
Herbicides for potential use in soybean pre-sowing burndown, to replace paraquat, for weeds that are difficult to control in Brazil.

Weed	Herbicide	References supporting the indication
Conyza spp.	Glufosinate	Oliveira Neto et al. (2010), Frene et al. (2018), Tahmasebi et al. (2018), Albrecht et al. (2020c)
	Diquat1	Gitsopoulos et al. (2018), Pinho et al. (2019), Zobiole et al. (2019), Albrecht et al. (2020a)
	Saflufenacil2	Dalazen et al. (2015), Zimmer et al. (2018), Cesco et al. (2019), Hedges et al. (2019), Piasecki et al. (2020)
Digitaria insularis	Glufosinate	Melo et al. (2012), Gemelli et al. (2013)
	ACCase3	Correia et al. (2015), Cassol et al. (2019), Vilela et al. (2019), Bianchi et al. (2020)
	Glyphosate4	Correia and Durigan (2009), Bianchi et al. (2020)
Eleusine indica	Glufosinate	Ulguim et al. (2013), Alcantara et al. (2016)
	ACCase5	Ulguim et al. (2013), Alcantara et al. (2016), Vilela et al. (2019)
	Glyphosate4	Ulguim et al. (2013), Minozzi et al. (2017)
Lolium spp.	Glufosinate	Schneider et al. (2015)
	Glyphosate4	Christoffoleti et al. (2005), Pereira et al. (2017)
	ACCase5	Roman et al. (2004), Christoffoleti et al. (2005), Pereira et al. (2017)
	ALS6	Trusler et al. (2007), Pereira et al. (2017)
Amaranthus spp.	Glufosinate	Sarangi et al. (2019), Takano et al. (2020a)
	Diquat	Dudic et al. (2020)
	Saflufenacil2	Sarangi et al. (2019)
	Glyphosate4	Norsworthy et al. (2008), Sarangi et al. (2019), Dudic et al. (2020)
	ALS6	Norsworthy et al. (2008), Chahal et al. (2018), Sarangi et al. (2019)
	Carfentrazone	Legleiter and Bradley (2008), Norsworthy et al. (2008)
	Flumioxazin	Norsworthy et al. (2008)
Spermacoce spp.	Glufosinate	Gallon et al. (2019), Kalsing et al. (2020)
	Saflufenacil2	Fadin et al. (2018), Gallon et al. (2019)
	Carfentrazone	Martins and Christoffoleti (2014)
	Flumioxazin	Fadin et al. (2018), Carbonari et al. (2020)
	ALS	Ramires et al. (2011), Martins and Christoffoleti (2014), Fadin et al. (2018)
Richardia brasiliensis	Glufosinate	Gallon et al. (2019), Kalsing et al. (2020)
	Diquat	Sharpe and Boyd (2019)
	Saflufenacil2	Vitorino et al. (2012), Gallon et al. (2019)
	Carfentrazone	Monquero et al. (2001), Gallon et al. (2019)
	Flumioxazin	Monquero et al. (2001), Gallon et al. (2019)
	ALS	Gallon et al. (2019), Kalsing et al. (2020)
Commelina spp.	Glufosinate	Brito et al. (2017), Ferreira et al. (2017)
	Diquat	Rodrigues and Almeida (2018)
	Saflufenacil2	Castro et al. (2017), Santos Junior et al. (2019)
	Carfentrazone	Maciel et al. (2011), Ferreira et al. (2017), Krolikowski et al. (2017)
	Flumioxazin	Silva et al. (2019), Carbonari et al. (2020)
	ALS	Maciel et al. (2011), Ramires et al. (2011)
Ambrosia artemisiifolia	Glufosinate	Barnes et al. (2017), Ganie and Jhala (2017)
	Saflufenacil2	Vink et al. (2012), Van Wely et al. (2014)
	Carfentrazone	Vink et al. (2012)
	Flumioxazin	Niekamp and Johnson (2001), Barnes et al. (2017)
	ALS	Van Wely et al. (2014), Ganie and Jhala (2017)
Andropogon bicornis	ACCase	Azevedo et al. (1999)

• ¹When there is no paraquat-resistant. ²Preferably associated with glyphosate. ³Herbicides from the group of ACCase inhibitors, in the case of D. insularis, especially clethodim, haloxyfop and quizalofop when rhizomatous. ⁴When there is no resistance to glyphosate. ⁵Herbicides from the ACCase inhibitor group when there is no resistance to them. ⁶ALS-inhibiting herbicides, when there is no resistance to them, in the case of L. multiflorum, especially imidazolinones and sulfonylureas.

Paraquat is widely used to control species such as Conyza spp., in Brazil and other countries, during the off-season and in pre-sowing, after the application of glyphosate plus other herbicides (Santos et al., 2015; Zobiole et al., 2018; Cesco et al., 2019; Flessner, Pittman, 2019; Soltani et al., 2020). In recent years, there has been a reduction in the effectiveness of paraquat in controlling Conyza spp. in Brazil. Cases of Conyza sumatrensis biotypes resistant to paraquat have been reported, and some biotypes have multiple resistance to paraquat and other herbicides (Pinho et al., 2019; Zobiole et al., 2019; Albrecht et al., 2020a).

There are 72 cases of weed biotypes resistant to paraquat worldwide (Table 4), in which Conyza bonariensis, C. canadensis, and C. sumatrensis represent 21 cases of biotypes resistant to this herbicide (Heap, 2022). In addition to the cases in Brazil, C. sumatrensis is reported to be resistant to paraquat and multiple herbicides in Paraguay (Albrecht et al., 2020b). These reports indicate that the performance of paraquat is decreasing because of its repeated use and increases selection pressure, highlighting the need for its replacement in the management of resistant weeds.

Table 4
Reported cases of weed species biotypes resistant to paraquat, diquat, and multiple, worldwide (March 2022).

Weed	Paraquat	Paraquat and diquat	Multiple
Alopecurus japonicus	1	-	-
Amaranthus blitum ssp. oleraceus	1	-	-
Bidens Pilosa	1	-	-
Convolvulus arvensis	1	-	-
Conyza bonariensis	3	1	1
Conyza canadensis	5	-	2
Conyza sumatrensis	5	1	3
Crassocephalum crepidioides	1	-	-
Cuphea carthagenenis	1	-	-
Eleusine indica	6	-	4
Epilobium ciliatum	2	-	-
Erigeron philadelphicus	1	-	-
Gamochaeta pensylvanica	2	-	-
Hedyotis verticillata	-	-	1
Hordeum murinum ssp. glaucum	-	2	-
Hordeum murinum ssp. leporinum	1	1	-
Ischaemum rugosum	1	-	-
Landoltia punctata	-	1	-
Lepidium virginicum	-	-	-
Lolium perenne ssp. multiflorum	-	-	2
Lolium rigidum	1	-	3
Mazus fauriei	1	-	-
Mazus pumilus	1	-	-
Mitracarpus hirtus	-	1	-
Poa annua	2	-	-
Sclerochloa dura	1	-	-
Solanum americanum	2	-	-
Solanum nigrum	3	-	-
Solanum ptycanthum	1	-	-
Vulpia bromoides	-	1	-
Youngia japonica	1	1	-

Heap (2022)

Thus, for the management of Conyza spp., even without paraquat banning, it would be necessary to use alternative herbicides in the pre-sowing burndown of soybeans. The ban on paraquat reinforces the need for the characterization and configuration of new management. Therefore, glufosinate has been highlighted (Eubank et al., 2008; Frene et al., 2018; Tahmasebi et al., 2018; Albrecht et al., 2020c; Cantu et al., 2021). Saflufenacil can also be used as an alternative for the control of Conyza spp. (Zimmer et al., 2018; Hedges et al., 2019). Some studies have indicated a synergistic effect of combinations of saflufenacil and glyphosate in the control of Conyza spp. (Dalazen et al., 2015; Piasecki et al., 2020), or even combined with the glufosinate mentioned above, in the control of other species that are difficult to control, such as Amaranthus palmeri (Takano et al., 2020a). These and other studies indicate that glufosinate and saflufenacil are important alternatives to paraquat in pre-sowing burndown, in the managing Conyza spp. and other weeds, particularly broadleaves, including the combination of these molecules, is very effective.

The synergistic effect of mixtures, such as glufosinate and protox-inhibiting herbicides, such as saflufenacil and carfentrazone, is a possible replacement for paraquat. Due to the paraquat ban, mixture is necessary for weed resistance management. Weeds proved to be resistant, demand more sophistication in chemical control, and strategies for integrated weed management.

Another potential substitute for paraquat in pre-sowing burndown is diquat, mainly for the managing of broadleaf weeds (Travlos, Chachalis, 2010; Gitsopoulos et al., 2018). However, to control Conyza spp., in plants with high resistance to paraquat, these herbicides have the same mechanism of action and the same chemical group (bipyridylium); therefore, the performance of the control was below the required level. For grasses such as Digitaria insularis, Eleusine indica, and Lolium multiflorum, diquat is not an excellent alternative for management. Generally, diquat has low efficacy but can be increased when combined with adjuvants; however, it still has unsatisfactory levels of control (Gitsopoulos et al., 2014). Its combination with ACCase-inhibiting graminicides and others still needs to be better elucidated for consistent application in the field.

Glufosinate, which can control Conyza spp. and other weeds, is also effective in the control of Digitaria sanguinalis (Aulakh, Jhala, 2015), D. insularis (Melo et al., 2012; Gemelli et al., 2013), and L. multiflorum (Schneider et al., 2015) and is promising for use in other grasses, when at an adequate stage for control or management in sequential applications. ACCase-inhibiting herbicides are prominent in managing these grasses (Correia et al., 2015; Vilela et al., 2019), in addition to ALS inhibitors and contact herbicides (Silva et al., 2017).

Paraquat is important for the control of grasses, particularly L. multiflorum (Pereira et al., 2017). However, when it was no longer an option, and considering the cases of resistance to glyphosate and ACCase inhibitors, in Brazil, of D. insularis (Carvalho et al., 2011; Takano et al., 2020b), E. indica (Vidal et al., 2006; Takano et al., 2017), and L. multiflorum (Roman et al., 2004; Vargas et al., 2016), the possibilities are becoming scarce. Therefore, combining herbicides and other tactics in grass management during pre-sowing is a requirement.

The combination of chemical control with mowing effectively controls D. insularis as an alternative, particularly for perennial plants (Correia et al., 2015; Raimondi et al., 2020). All possible control strategies must be used and associated with the diversification of production systems. Therefore, mechanical control practices, such as mowing or mechanical weeding, are potentially more requested in the field.

Diversifying tactics and observing the requirement for herbicide combinations within chemical control will demand greater technical accuracy applying such practices in the field. An example of these emerging challenges, whether in the replacement of paraquat or another herbicide due to resistance, is the need to avoid incompatible and antagonistic mixtures. The benefits of mixtures of herbicides can be significant and synergistic, which is desirable; however, problems can become more and reoccur. The low performance of combinations of herbicides with an immediate contact effect, such as diquat, with systemic herbicides, has been reported (Wehtje et al., 2008). In addition, there is antagonism between ACCase inhibitors and synthetic auxins (Underwood et al., 2016; Webster et al., 2019; Bauer et al., 2021) or between ACCase inhibitors and ALS inhibitors.

Although they are not classified as burndown herbicides, pre-emergent herbicides contribute to managing weeds, such as D. insularis and Conyza spp. The use of these herbicides has already been recommended even without the ban of paraquat. Due to the cases of resistance and its prohibition, pre-emergent herbicides have become more significant. Therefore, the pre-emergent herbicides are considerable in control, diminishing emergence flows from the soil seed bank, contributing to the prolongation of the period before interference in the crop and is essential in the management of resistance (by reducing the pressure of selection).

To control D. insularis and other grassy weeds, the herbicides s-metolachlor, flumioxazin, imazethapyr, sulfentrazone, clomazone can be used (Drehmer et al., 2015), with effective control in management systems with cover crops (Marochi et al., 2018). In addition, the initial growth-inhibiting herbicides, such as pendimethalin and trifluralin, or commercial premixes, such as flumioxazin/imazethapyr, sulfentrazone/diuron, and imazapic/imazapyr, can be used for weed control. In the case of grasses, pre-emergent herbicides are essential alternatives in the rotation of mechanisms of action to avoid the possible selection pressure for resistance and to help preserve the few herbicide molecules still effective in the post-emergence of some species.

To manage Conyza spp. and other eudicot weeds, herbicides can be highlighted, either with action in pre- or post-emergence, ALS inhibitors (cloransulam, chlorimuron, diclosulam, imazethapyr, imazapic) (Braz et al., 2017; Cesco et al., 2019). In addition, pre-emergent protox-inhibiting herbicides, such as flumioxazin and sulfentrazone (Zimmer et al., 2018). Furthermore, some commercial premixes are already available to the producer or soon available, such as sulfentrazone/diuron, imazethapyr/flumioxazin, saflufenacil/imazethapyr, among others (Albrecht et al., 2020c). Moreover, non-chemical measures, such as cover crops and straw formation, should be highlighted for the management of Conyza spp. (Campiglia et al., 2015; Guareschi et al., 2020), and other weeds.

New herbicide-resistant crops technologies must be included in the management strategy. The technologies Enlist E3™ (tolerance to 2,4-D, glyphosate, and glufosinate), Roundup Ready™ 2 Xtend™ (dicamba and glyphosate), Liberty Link^® GT27™ (glufosinate, glyphosate, and isoxaflutole) will bring options for weed management in the pre- or post-emergence stages of the crop. For maize, combining technologies with the possibility of using glyphosate, glufosinate, haloxyfop, and 2,4-D will be useful. All these herbicides, in different situations, with various transgenic events (current and to come), can be used with other tools, providing alternative management in the absence of paraquat.

Therefore, replacing paraquat with another herbicide is not always possible, with equivalent results and similar costs. The use of herbicides that require more significant investment and the need for herbicide mixtures, with action in pre- or post-emergence, will be a routine in many scenarios, particularly in the absence of paraquat, single or multiple resistance to herbicides is identified in the target population. Possible increases in the cost of herbicides are justified because of potential losses due to weed interference. Herbicide-tolerant transgenic crops can be used as auxiliary tools, allowing the inclusion of new herbicides, including post-emergence of the crop, generating specific compensatory effects due to the lack of paraquat and resistance management. However, there will never be nor have there been single solutions, and it is increasingly necessary to include other controls, such as cultural and mechanical. In integrated weed management, the combination of control strategies within good agricultural practices is vital.

6.Conclusions

Paraquat has been widely used herbicide, with many notable advantages and benefits. Nevertheless, its banning forces new approaches, caused by necessary adjustments in the positioning of substitute herbicides in pre-harvest desiccation and weed management. The substitutes for pre-harvest desiccation of different crops are diquat, glufosinate, and protox-inhibiting herbicides. For weed management, there is higher diversity, including glufosinate, diquat, saflufenacil, and numerous possible mixtures. However, the most significant challenge is finding alternatives for grasses weed control.

References

• Agência Nacional de Vigilância Sanitária - Anvisa. [Paraquat: monographic index]. Brasília: Agência Nacional de Vigilância Sanitária; 2020b. Portuguese
• Agência Nacional de Vigilância Sanitária - Anvisa. [Resolution CBD No. 428, of October 7, 2020. Amends resolution CBD No. 177, of September 21, 2017, which provides for the ban on the active ingredient paraquat in pesticide products in the country and on transitional measures to mitigate risks, to address the use of stocks held by Brazilian farmers of products based on the active ingredient paraquat for crop management in the 2020/2021 crop year]. Diário Oficial União. Oct 8, 2020a.
• Agência Nacional de Vigilância Sanitária - Anvisa. [Vote of the board of sanitary regulation No. 56, of September 19, 2017. Analyzes the toxicological reassessment of the active ingredient paraquat]. Brasília: Agência Nacional de Vigilância Sanitária; 2017. Portuguese
• Akhavein AA, Linscott DL. The dipyridylium herbicides, paraquat and diquat. In: Gunther FA, editor. Residue reviews. vol. 23. New York: Springer; 1968. p. 97-145.
• Albrecht AJP, Albrecht LP, Silva AFM, Ramos RA, Corrêa NB, Carvalho MG et al. Control of Conyza spp. with sequential application of glufosinate in soybean pre-sowing. Cienc Rural. 2020c;50(9):1-9. Available from: https://doi.org/10.1590/0103-8478cr20190868
  » https://doi.org/10.1590/0103-8478cr20190868
• Albrecht AJP, Pereira VGC, Souza CNZ, Zobiole LHS, Albrecht LP, Adegas FS. Multiple resistance of Conyza sumatrensis to three mechanisms of action of herbicides. Acta Sci Agron. 2020a;42:1-9. Available from: https://doi.org/10.4025/actasciagron.v42i1.42485
  » https://doi.org/10.4025/actasciagron.v42i1.42485
• Albrecht AJP, Thomazini G, Albrecht LP, Pires A, Lorenzetti JB, Danilussi MTY et al. Conyza sumatrensis resistant to paraquat, glyphosate and chlorimuron: confirmation and monitoring the first case of multiple resistance in Paraguay. Agriculture. 2020b;10(12):1-11. Available from: https://doi.org/10.3390/agriculture10120582
  » https://doi.org/10.3390/agriculture10120582
• Alcantara R, Fernandez P, Smeda RJ, Alves PL, De Prado R. Response of Eleusine indica and Paspalum distichum to glyphosate following repeated use in citrus groves. Crop Prot. 2016;79:1-7. Available from: https://doi.org/10.1016/j.cropro.2015.09.027
  » https://doi.org/10.1016/j.cropro.2015.09.027
• Amondham W, Parkpian P, Polprasert C, Delaune RD, Jugsujinda A. Paraquat adsorption, degradation, and remobilization in tropical soils of Thailand. J Environ Sci Health Part B. 2006;41(5):485-507. Available from: https://doi.org/10.1080/03601230600701635
  » https://doi.org/10.1080/03601230600701635
• Araújo DL, Lazzari MP, Dutra R, Lajus CR, Klein C, Cericato A, Sordi A et al. [Influence of soybean desiccation periods on its germination potential and yield components]. Rev Bras Cienc Agrar. 2018;13(4):1-6. Portuguese. Available from: https://doi.org/10.5039/agraria.v13i4a5584
  » https://doi.org/10.5039/agraria.v13i4a5584
• Argenta G, Silva PRF, Fleck NG, Bortolini CG, Neves R, Agostinetto D. [Effects of mechanical and chemical management of black oat on maize grown in succession and on alexandergrass control]. Pesq Agropec Bras. 2001;36(6):851-60. Portuguese. Available from: https://doi.org/10.1590/S0100-204X2001000600002
  » https://doi.org/10.1590/S0100-204X2001000600002
• Aulakh JS, Jhala AJ. Comparison of glufosinate-based herbicide programs for broad-spectrum weed control in glufosinate resistant soybean. Weed Technol. 2015;29(3):419-30. Available from: https://doi.org/10.1614/WT-D-15-00014.1
  » https://doi.org/10.1614/WT-D-15-00014.1
• Azevedo DMP, Romam ES, Lisboa SM. [Controlo f weed grass species in rubber plantation]. Rev Cienc Agrar. 1999;(31):21-8.
• Baltazar MT, Dinis-Oliveira RJ, Duarte JA., Lourdes Bastos M, Carvalho F. Paraquat research: do recent advances in limiting its toxicity make its use safer? Br J Pharmacol. 2013b;168(1):44-5. Available from: https://doi.org/10.1111/j.1476-5381.2012.02017.x
  » https://doi.org/10.1111/j.1476-5381.2012.02017.x
• Baltazar MT, Dinis-Oliveira RJ, Guilhermino L, Lourdes Bastos M, Duarte JA, Carvalho F. New formulation of paraquat with lysine acetylsalicylate with low mammalian toxicity and effective herbicidal activity. Pest Manag Sci. 2013a;69(4):553-8. Available from: https://doi.org/10.1002/ps.3412
  » https://doi.org/10.1002/ps.3412
• Barnes ER, Knezevic SZ, Sikkema PH, Lindquist JL, Jhala AJ. Control of glyphosate-resistant common ragweed (Ambrosia artemisiifolia L.) in glufosinate-resistant soybean [Glycine max (L.) Merr]. Front Plant Sci. 2017;8:1-10. Available from: https://doi.org/10.3389/fpls.2017.01455
  » https://doi.org/10.3389/fpls.2017.01455
• Bauer FE, Albrecht AJP, Albrecht LP, Silva AFM, Barroso AAM, Danilussi MTY. Digitaria insularis control by using herbicide mixtures application in soybean pre-emergence. Rev Fac Nac Agron Medellín. 2021;74(1):9403-11. Available from: https://doi.org/10.15446/rfnam.v74n1.89032
  » https://doi.org/10.15446/rfnam.v74n1.89032
• Bellaloui N, Bruns HA, Abbas HK, Fisher DK, Mengistu A. Effects of harvest-aids on seed nutrition in soybean under midsouth USA conditions. Plants. 2020;9(8):1-16. Available from: https://doi.org/10.3390/plants9081007
  » https://doi.org/10.3390/plants9081007
• Bianchi L, Anunciato VM, Gazola T, Perissato SM, Dias RC, Tropaldi L et al. Effects of glyphosate and clethodim alone and in mixture in sourgrass (Digitaria insularis). Crop Prot. 2020;138:105322. Available from: https://doi.org/10.1016/j.cropro.2020.105322
  » https://doi.org/10.1016/j.cropro.2020.105322
• Bolliger A, Magid J, Amado JCT, Neto FS, Santos Ribeiro MF, Calegari A et al. Taking stock of the Brazilian “zero-till revolution”: a review of landmark research and farmers’ practice. Adv Agron. 2006;91:47-110. Available from: https://doi.org/10.1016/S0065-2113(06)91002-5
  » https://doi.org/10.1016/S0065-2113(06)91002-5
• Boudreaux JM, Griffin JL. Application timing of harvest aid herbicides affects soybean harvest and yield. Weed Technol. 2011;25(1):38-43. Available from: https://doi.org/10.1614/WT-D-10-00045.1
  » https://doi.org/10.1614/WT-D-10-00045.1
• Braz GBP, Oliveira Junior RS, Zobiole LHS, Rubin RS, Voglewede C, Constantin J et al. Sumatran fleabane (Conyza sumatrensis) control in no-tillage soybean with diclosulam plus halauxifen-methyl. Weed Technol. 2017;31(2):184-92. Available from: https://doi.org/10.1017/wet.2016.28
  » https://doi.org/10.1017/wet.2016.28
• Brito IPFS, Marchesi BB, Silva IPFE, Carbonari CA, Velini ED. Variation in the sensitivity of wandering jew plants to glufosinate ammonium. Rev Caatinga. 2017;30(3):595-601. Available from: https://doi.org/10.1590/1983-21252017v30n307rc
  » https://doi.org/10.1590/1983-21252017v30n307rc
• Bromilow RH. Paraquat and sustainable agriculture. Pest Manag Sci. 2004;60(4):340-9. Available from: https://doi.org/10.1002/ps.823
  » https://doi.org/10.1002/ps.823
• Camargo ER, Zapiola ML, Avila LA, Garcia MA, Plaza G, Gazziero DLP et al. Current situation regarding herbicide regulation and public perception in South America. Weed Sci. 2020;68(3):232-9. Available from: https://doi.org/10.1017/wsc.2020.14
  » https://doi.org/10.1017/wsc.2020.14
• Campiglia E, Radicetti E, Mancinelli R. Cover crops and mulches influence weed management and weed flora composition in strip-tilled tomato (Solanum lycopersicum). Weed Res. 2015;55(4):416-25. Available from: https://doi.org/10.1111/wre.12156
  » https://doi.org/10.1111/wre.12156
• Cantu RM, Albrecht LP, Albrecht AJP, Silva AFM, Danilussi MT, Lorenzetti JB. Herbicide alternative for Conyza sumatrensis control in pre-planting in no-till soybeans. Adv Weed Sci. 2021;39:1-9. Available from: https://doi.org/10.51694/AdvWeedSci/2021;39:000012
  » https://doi.org/10.51694/AdvWeedSci/2021;39:000012
• Carbonari CA, Gomes GLGC, Krenchinski FH, Simões PS, Castro EB, Velini ED. Dynamics and efficacy of sulfentrazone, flumioxazin, and isoxaflutole herbicides applied on eucalyptus harvest residues. New Forest. 2020;51(4):723-37. Available from: https://doi.org/10.1007/s11056-019-09756-3
  » https://doi.org/10.1007/s11056-019-09756-3
• Carvalho FT. Eficácia do flumioxazin aplicado na dessecação pré-colheita da soja e efeito residual no controle de plantas daninhas no milho safrinha. Cult Agron. 2017;26(4):683-93. Available from: https://doi.org/10.32929/2446-8355.2017v26n4p683-693
  » https://doi.org/10.32929/2446-8355.2017v26n4p683-693
• Carvalho LB, Cruz-Hipolito H, González-Torralva F, Alves PLCA, Christoffoleti PJ, Prado R. Detection of sourgrass (Digitaria insularis) biotypes resistant to glyphosate in Brazil. Weed Sci. 2011;59(2):171-6. Available from: https://doi.org/10.1614/WS-D-10-00113.1
  » https://doi.org/10.1614/WS-D-10-00113.1
• Cassol M, Mattiuzzi MD, Albrecht AJP, Albrecht LP, Baccin LC, Souza CNZ. Efficiency of isolated and associated herbicides to control glyphosate-resistant sourgrass. Planta Daninha. 2019;37:1-8. Available from: https://doi.org/10.1590/S0100-83582019370100060
  » https://doi.org/10.1590/S0100-83582019370100060
• Castoldi C, Radunz L, Galon L, Aspiazú I, Forte C, Scariot M et al. Physiological quality of carioca bean seeds submitted to the application of desiccant herbicides in two periods. Planta Daninha 2019;37:1-3. Available from: https://doi.org/10.1590/S0100-83582019370100154
  » https://doi.org/10.1590/S0100-83582019370100154
• Castro EB, Carbonari CA, Velini ED, Ben R, Belapart D, Gomes GLGC et al. [Spray deposition and control effectiveness of glyphosate and saflufenacil associated with adjuvants]. Rev Bras Herb. 2017;16(2):103-11. Portuguese. Available from: https://doi.org/10.7824/rbh.v16i2.508
  » https://doi.org/10.7824/rbh.v16i2.508
• Cesco VJS, Nardi R, Krenchinski FH, Albrecht AJP, Rodrigues DM, Albrecht LP. Management of resistant Conyza spp. during soybean pre-sowing. Planta Daninha 2019;37:1-9. Available from: https://doi.org/10.1590/S0100-83582019370100039
  » https://doi.org/10.1590/S0100-83582019370100039
• Chahal PS, Irmak S, Gaines T, Amundsen K, Jugulam M, Jha P et al. Control of photosystem II-and 4-hydroxyphenylpyruvate dioxygenase inhibitor-resistant Palmer amaranth (Amaranthus palmeri) in conventional corn. Weed Technol. 2018;32(3):326-35. Available from: https://doi.org/10.1017/wet.2017.111
  » https://doi.org/10.1017/wet.2017.111
• Christoffoleti PJ, Trentin R, Tocchetto S, Marochi A, Galli AJB, López-Ovejero RF et al. Alternative herbicides to manage Italian ryegrass (Lolium multiflorum Lam) resistant to glyphosate at different phenological stages. J Environ Sci Health B. 2005;40(1):59-67. Available from: https://doi.org/10.1081/LESB-200034221
  » https://doi.org/10.1081/LESB-200034221
• Correia NM, Acra LT, Balieiro G. Chemical control of different Digitaria insularis populations and management of a glyphosate-resistant population. Planta Daninha. 2015;33(1):93-101. Available from: https://doi.org/10.1590/S0100-83582015000100011
  » https://doi.org/10.1590/S0100-83582015000100011
• Correia NM, Durigan JC. [Chemical management of adult Digitaria insularis with glyphosate alone and mixture with chlorimuron-ethyl or quizalofop-p-tefuril in a no-tillage field]. Bragantia 2009;68(3):689-97. Portuguese. Available from: https://doi.org/10.1590/S0006-87052009000300016
  » https://doi.org/10.1590/S0006-87052009000300016
• Costa NV, Neunfeld TH, Ohland T, Piano JT, Klein J. Directed-spray application of paraquat and diuron in physic nut plants. Planta Daninha 2013;31(4):987-96. Available from: https://doi.org/10.1590/S0100-83582013000400025
  » https://doi.org/10.1590/S0100-83582013000400025
• Cronshey JFH. A review of experimental work with diquat and related compounds. Weed Res. 1961;1(1):68-77. Available from: https://doi.org/10.1111/j.1365-3180.1961.tb00007.x
  » https://doi.org/10.1111/j.1365-3180.1961.tb00007.x
• Dalazen G, Kruse ND, Machado SLO, Balbinot A. [Synergism of the glyphosate and saflufenacil combination for controlling hairy fleabane]. Pesq Agropec Trop. 2015;45(2):249-56. Portuguese. Available from: https://doi.org/10.1590/1983-40632015v4533708
  » https://doi.org/10.1590/1983-40632015v4533708
• Delgado CML, Coelho CMMD, Buba GP. Mobilization of reserves and vigor of soybean seeds under desiccation with glufosinate ammonium. J Seed Sci. 2015;37(2):154-61. Available from: https://doi.org/10.1590/2317-1545v37n2148445
  » https://doi.org/10.1590/2317-1545v37n2148445
• Drehmer MH, Zagonel J, Ferreira C, Senger M. [Herbicides efficacy applied in pre-emergency to control Digitaria insularis in bean]. Rev Bras Herb. 2015;14(2):141-7. Portuguese. Available from: https://doi.org/10.7824/rbh.v14i2.395
  » https://doi.org/10.7824/rbh.v14i2.395
• Dudic M, Meseldzija M, Ljevnaic-Masic B, Rajkovic M, Markovic T, Begovic R et al. Weed composition and control in apple orchards under intensive and extensive floor management. Chil J Agric Res. 2020;80(4):546-60. Available from: https://doi.org/10.4067/S0718-58392020000400546
  » https://doi.org/10.4067/S0718-58392020000400546
• Ekboir JM. Research and technology policies in innovation systems: zero tillage in Brazil. Res Policy. 2003;32(4):573-86. Available from: https://doi.org/10.1016/S0048-7333(02)00058-6
  » https://doi.org/10.1016/S0048-7333(02)00058-6
• Eubank TW, Poston DH, Nandula VK, Koger CH, Shaw DR, Reynolds DB. Glyphosate-resistant horseweed (Conyza canadensis) control using glyphosate-, paraquat-, and glufosinate-based herbicide programs. Weed Technol. 2008;22(1):16-21. Available from: https://doi.org/10.1614/WT-07-038.1
  » https://doi.org/10.1614/WT-07-038.1
• Fadin DA, Tornisielo VL, Barroso AAM, Ramos S, Reis FC, Monquero PA. Absorption and translocation of glyphosate in Spermacoce verticillata and alternative herbicide control. Weed Res. 2018;58(5):389-96. Available from: https://doi.org/10.1111/wre.12329
  » https://doi.org/10.1111/wre.12329
• Ferebee JH, Cahoon CW, Flessner ML, Langston DB, Arancibia R, Hines TE et al. Comparison of diquat, glufosinate, and saflufenacil for desiccation of ‘Dark Red Norland’Potato. HortTech. 2019;29(5):643-8. Available from: https://doi.org/10.21273/HORTTECH04327-19
  » https://doi.org/10.21273/HORTTECH04327-19
• Ferreira SD, Salvalaggio AC, Moratelli G, Vasconcelos ED, Costa NV. Commelina species control with desiccants alone and in mixtures. Planta Daninha. 2017;35:e017165664. Available from: https://doi.org/10.1590/S0100-83582017350100074
  » https://doi.org/10.1590/S0100-83582017350100074
• Finoto EL, Sediyama T, Albuquerque J, Soares MBB, Galli JA, Cordeiro J et al. Anticipation and harvest delay in oil and protein contents of soybean seeds, grow crops Valiosa RR. Sci Agropecu. 2017;8(2):99-107. Available from: https://doi.org/10.17268/sci.agropecu.2017.02.02
  » https://doi.org/10.17268/sci.agropecu.2017.02.02
• Flessner ML, Pittman KB. Horseweed control with preplant herbicides after mechanical injury from small grain harvest. Agron J. 2019;111(6):3274-80. Available from: https://doi.org/10.2134/agronj2019.03.0174
  » https://doi.org/10.2134/agronj2019.03.0174
• Freitas PL, Landers JN. The transformation of agriculture in Brazil through development and adoption of zero tillage conservation agriculture. Int Soil Water Conserv Res. 2014;2(1):35-46. Available from: https://doi.org/10.1016/S2095-6339(15)30012-5
  » https://doi.org/10.1016/S2095-6339(15)30012-5
• Frene RL, Simpson DM, Buchanan MB, Vega ET, Ravotti ME, Valverde PP. Enlist E3™ Soybean sensitivity and Enlist™ herbicide-based program control of Sumatran fleabane (Conyza sumatrensis). Weed Technol. 2018;32(4):416-23. Available from: https://doi.org/10.1017/wet.2018.29
  » https://doi.org/10.1017/wet.2018.29
• Funderburk Jr HH, Lawrence JM. Mode of action and metabolism of diquat and paraquat. Weeds 1964;12(4):259-64. Available from: https://doi.org/10.2307/4040748
  » https://doi.org/10.2307/4040748
• Gallon M, Trezzi MM, Pagnoncelli Junior FB, Pasini R, Viecelli M, Cavalheiro BM. Chemical management of broadleaf buttonweed and Brazilian pusley in different application methods. Planta Daninha 2019;37:1-11. Available from: https://doi.org/10.1590/S0100-83582019370100098
  » https://doi.org/10.1590/S0100-83582019370100098
• Ganie ZA, Jhala AJ. Glyphosate-resistant common ragweed (Ambrosia artemisiifolia) in Nebraska: confirmation and response to postemergence corn and soybean herbicides. Weed Technol. 2017;31(2):225-37. Available from: https://doi.org/10.1017/wet.2016.26
  » https://doi.org/10.1017/wet.2016.26
• Gemelli A, Oliveira Júnior RS, Constantin J, Braz GBP, Campos Jumes TM, Gheno EA et al. Estratégias para o controle de capim-amargoso (Digitaria insularis) resistente ao glyphosate na cultura milho safrinha. Rev Bras Herb. 2013;12(2):162-70. Available from: https://doi.org/10.7824/rbh.v12i2.201
  » https://doi.org/10.7824/rbh.v12i2.201
• Gil HW, Kang MS, Yang JO, Lee EY, Hong SY. Association between plasma paraquat level and outcome of paraquat poisoning in 375 paraquat poisoning patients. Clin Toxicol. 2008;46(6):515-8. Available from: https://doi.org/10.1080/15563650701549403
  » https://doi.org/10.1080/15563650701549403
• Gitsopoulos TK, Damalas CA, Georgoulas I. Improving diquat efficacy on grasses by adding adjuvants to the spray solution before use. Planta Daninha. 2014;32(2):355-60. Available from: https://doi.org/10.1590/S0100-83582014000200013
  » https://doi.org/10.1590/S0100-83582014000200013
• Gitsopoulos TK, Damalas CA, Georgoulas I. Optimizing diquat efficacy with the use of adjuvants. Phytoparasitica. 2018;46(5):715-22. Available from: https://doi.org/10.1007/s12600-018-0698-y
  » https://doi.org/10.1007/s12600-018-0698-y
• Goffnett AM, Sprague CL, Mendoza F, Cichy KA. Preharvest herbicide treatments affect black bean desiccation, yield, and canned bean color. Crop Sci. 2016;56(4):1962-9. Available from: https://doi.org/10.2135/cropsci2015.08.0469
  » https://doi.org/10.2135/cropsci2015.08.0469
• Guareschi A, Cechin J, Bianchi MA, Kruse ND, Piccinini F, Pinheiro RT et al. Cover plants as a suppression and increasing tool to hairy fleabane control. Rev Bras Cienc Agrar. 2020;15(2):1-8. Available from: https://doi.org/10.5039/agraria.v15i2a7522
  » https://doi.org/10.5039/agraria.v15i2a7522
• Hawkes TR. Mechanisms of resistance to paraquat in plants. Pest Manag Sci. 2014;70(9):1316-23. Available from: https://doi.org/10.1002/ps.3699
  » https://doi.org/10.1002/ps.3699
• Heap I. The international herbicide-resistant weed database. Weedscience. 2022[Access March 21, 2022]. Available at: http://www.weedscience.org/
  » http://www.weedscience.org/
• Hedges BK, Soltani N, Robinson DE, Hooker DC, Sikkema PH. Control of glyphosate-resistant Canada fleabane in Ontario with multiple effective modes-of-action in glyphosate/dicamba-resistant soybean. Can J Plant Sci. 2019;99(1):78-83. Available from: https://doi.org/10.1139/cjps-2018-0067
  » https://doi.org/10.1139/cjps-2018-0067
• Huang Y, Zhan H, Bhatt P, Chen S. Paraquat degradation from contaminated environments: Current achievements and perspectives. Front Microbiol. 2019;10:1-9. Available from: https://doi.org/10.3389/fmicb.2019.01754
  » https://doi.org/10.3389/fmicb.2019.01754
• Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis - Ibama. [Pesticides marketing reports]. Brasília: Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis; 2022[access March 21, 2022]. Portuguese. Available from: http://ibama.gov.br/agrotoxicos/relatorios-de-comercializacao-de-agrotoxicos
  » http://ibama.gov.br/agrotoxicos/relatorios-de-comercializacao-de-agrotoxicos
• Kalsing A, Rossi CVS, Lucio FR, Minozzi GB, Goncalves FP, Valeriano R. Efficacy of control of glyphosate-tolerant species of the Rubiaceae family through double-knockdown applications. Planta Daninha. 2020;38:1-9. Available from: https://doi.org/10.1590/S0100-83582020380100023
  » https://doi.org/10.1590/S0100-83582020380100023
• Kim JW, Kim DS. Paraquat: toxicology and impacts of its ban on human health and agriculture. Weed Sci. 2020;68(3):208-13. Available from: https://doi.org/10.1017/wsc.2019.70
  » https://doi.org/10.1017/wsc.2019.70
• Krenchinski FH, Cesco VJS, Rodrigues DM, Pereira VGC, Albrecht AJP, Albrecht LP. Yield and physiological quality of wheat seeds after desiccation with different herbicides. J Seed Sci. 2017;39(3):254-61. Available from: https://doi.org/10.1590/2317-1545v39n3172506
  » https://doi.org/10.1590/2317-1545v39n3172506
• Krolikowski V, Carvalho FT, Teodoro PE. Morpho-physiological behavior of Commelina benghalensis in response to herbicides aplied in post-emergency. Biosci J. 2017;33(2):268-75. Available from: https://doi.org/10.14393/BJ-v33n2-32845
  » https://doi.org/10.14393/BJ-v33n2-32845
• Kumar H, Singh VB, Meena BL, Gaur S, Singla R. Paraquat poisoning: a case report. J Clin Diagn Res. 2016;10(2):1-2. Available from: https://doi.org/10.7860/JCDR/2016/15858.7204
  » https://doi.org/10.7860/JCDR/2016/15858.7204
• Lamego FP, Gallon M, Basso CJ, Kulczynski SM, Ruchel Q, Kaspary TE et al. Pre-harvest application and effects on yield and physiological quality of soybean seeds. Planta Daninha. 2013;31(4):929-38. Available from: https://doi.org/10.1590/S0100-83582013000400019
  » https://doi.org/10.1590/S0100-83582013000400019
• Legleiter TR, Bradley KW. Glyphosate and multiple herbicide resistance in common waterhemp (Amaranthus rudis) populations from Missouri. Weed Sci. 2008;56(4):582-7. Available from: https://doi.org/10.1614/WS-07-204.1
  » https://doi.org/10.1614/WS-07-204.1
• Maciel CDG, Poletine JP, Amstalden SL, Gazziero DLP, Raimondi MA, Lima GRG et al. Glyphosate tank mixtures controlling Commelina benghalensis, Tridax procumbens and Cenchrus echinatus in soybean Roundup Ready®. Rev Ceres. 2011;58(1):35-42. Available from: https://doi.org/10.1590/S0034-737X2011000100006
  » https://doi.org/10.1590/S0034-737X2011000100006
• Marambe B, Herath S. Banning of herbicides and the impact on agriculture: the case of glyphosate in Sri Lanka. Weed Sci. 2020;68(3):246-52. Available from: https://doi.org/10.1017/wsc.2019.71
  » https://doi.org/10.1017/wsc.2019.71
• Marochi A, Ferreira A, Takano HK, Oliveira Junior RS, Lopez-Ovejero RF. Managing glyphosate-resistant weeds with cover crop associated with herbicide rotation and mixture. Cienc Agrotecnol. 2018;42(4):381-94. Available from: https://doi.org/10.1590/1413-70542018424017918
  » https://doi.org/10.1590/1413-70542018424017918
• Martins BAB, Christoffoleti PJ. Herbicide efficacy on Borreria densiflora control in pre-and post-emergence conditions. Planta Daninha. 2014;32(4):817-25. Available from: https://doi.org/10.1590/S0100-83582014000400017
  » https://doi.org/10.1590/S0100-83582014000400017
• McNaughton KE, Blackshaw RE, Waddell KA, Gulden RH, Sikkema PH, Gillard CL. Effect of five desiccants applied alone and in combination with glyphosate in dry edible bean (Phaseolus vulgaris L.). Can J Plant Sci. 2015;95(6):1235-42. Available from: https://doi.org/10.4141/cjps-2015-098
  » https://doi.org/10.4141/cjps-2015-098
• Melo MSC, Rosa LE, Brunharo CACG, Nicolai M, Christoffoleti PJ. [Chemical control alternatives for sourgrass (Digitaria insularis) resistant to glyphosate]. Rev Bras Herb. 2012;11(2):195-203. Portuguese. Available from: https://doi.org/10.7824/rbh.v11i2.145
  » https://doi.org/10.7824/rbh.v11i2.145
• Ministério da Agricultura, Pecuária e Abastecimento (BR). [Agrofit: System of phytosanitary pesticides]. Brasília: Ministério da Agricultura, Pecuária e Abastecimento; 2022[Access March 22, 2022]. Portuguese. Available from: http://agrofit.agricultura.gov.br/agrofit_cons/principal_agrofit_cons
  » http://agrofit.agricultura.gov.br/agrofit_cons/principal_agrofit_cons
• Minozzi GB, Christoffoleti PJ, Monquero PA, Zobiole LHS, Pereira GR, Duck L. [Control in soybean pre plant of volunteer glyphosate and ammonium glufosinate tolerant cotton and Eleusine indica]. Rev Bras Herb. 2017;16(3):183-91. Portuguese. Available from: https://doi.org/10.7824/rbh.v16i3.547
  » https://doi.org/10.7824/rbh.v16i3.547
• Monquero PA, Christoffoleti PJ, Santos CTD. [Glyphosate combined with alternative herbicides for vegetation management]. Planta Daninha. 2001;19(3):375-80. Portuguese. Available from: https://doi.org/10.1590/S0100-83582001000300010
  » https://doi.org/10.1590/S0100-83582001000300010
• Muhamad H, Ismail BS, Sameni M, Mat N. Adsorption study of 14 C-paraquat in two Malaysian agricultural soils. Environ Monit Assess. 2011;176(1-4):43-50. Available from: https://doi.org/10.1007/s10661-010-1565-6
  » https://doi.org/10.1007/s10661-010-1565-6
• Neves R, Fleck NG, Vidal RA. [Establishment of corn seeding time interval after desiccation of oats with herbicides]. Cienc Rural. 1999;29(4):603-8. Portuguese. Available from: https://doi.org/10.1590/S0103-84781999000400005
  » https://doi.org/10.1590/S0103-84781999000400005
• Niekamp JW, Johnson WG. Weed management with sulfentrazone and flumioxazin in no-tillage soyabean (Glycine max). Crop Prot. 2001;20(3):215-20. Available from: https://doi.org/10.1016/S0261-2194(00)00129-0
  » https://doi.org/10.1016/S0261-2194(00)00129-0
• Norsworthy JK, Griffith GM, Scott RC, Smith KL, Oliver LR. Confirmation and control of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in Arkansas. Weed Technol. 2008;22(1):108-13. Available from: https://doi.org/10.1614/WT-07-128.1
  » https://doi.org/10.1614/WT-07-128.1
• Oliveira Neto AM; Guerra N, Dan HA, Braz GBP, Jumes TMC, Santos G et al.[ Conyza bonariensis management with glyphosate + 2,4-D and glufosinate according to development stage]. Rev Bras Herb. 2010;9(3):73-80. Portuguese. Available from: https://doi.org/10.7824/rbh.v9i3.87
  » https://doi.org/10.7824/rbh.v9i3.87
• Pateiro-Moure M, Nóvoa-Muñoz JC, Arias-Estévez M, López-Periago E, Martínez-Carballo E, Simal-Gándara J. Quaternary herbicides retention by the amendment of acid soils with a bentonite-based waste from wineries. J Hazard Mat. 2009;164(2-3):769-75. Available from: https://doi.org/10.1016/j.jhazmat.2008.08.071
  » https://doi.org/10.1016/j.jhazmat.2008.08.071
• Perboni LT, Agostinetto D, Vargas L, Cechin J, Zandoná RR, Farias HDS. Yield, germination and herbicide residue in seeds of preharvest desiccated wheat. J Seed Sci. 2018;40(3):304-12. Available from: https://doi.org/10.1590/2317-1545v40n3191284
  » https://doi.org/10.1590/2317-1545v40n3191284
• Pereira IS, Soares LH, Cabral EMA, Fontana DC, Umburanas RC, Santos LLS et al. Harvest-aid herbicides influence soybean seed yield, quality and oxidative metabolism. Rev Bras Cienc Agrar. 2020;15(2):1-7. Available from: https://doi.org/10.5039/agraria.v15i2a7022
  » https://doi.org/10.5039/agraria.v15i2a7022
• Pereira LV, Carvalho LB, Dal Magro T. [Chemical control of Lolium multiflorum: effect of biotype and time of spraying]. Rev Cienc Agrovet. 2017;16(3):338-41. Portuguese. Available from: https://doi.org/10.5965/223811711632017338
  » https://doi.org/10.5965/223811711632017338
• Pereira T, Coelho CMM, Souza CA, Mantovani A, Mathias V. [Chemical desiccation for early harvest in soybean cultivars]. Semina Cienc Agrar. 2015;36(4):2383-94. Portuguese. Available from: https://doi.org/10.5433/1679-0359.2015v36n4p2383
  » https://doi.org/10.5433/1679-0359.2015v36n4p2383
• Piasecki C, Carvalho IR, Avila LA, Agostinetto D, Vargas L. Glyphosate and saflufenacil: Elucidating their combined action on the control of glyphosate-resistant Conyza bonariensis Agriculture. 2020;10(6):1-16. Available from: https://doi.org/10.3390/agriculture10060236
  » https://doi.org/10.3390/agriculture10060236
• Pinho CF, Leal JFL, Souza AS, Oliveira GFPB, Oliveira C, Langaro AC et al. First evidence of multiple resistance of Sumatran fleabane (Conyza sumatrensis (Retz.) E.Walker) to five-mode-of-action herbicides. Aust J Crop Sci. 2019;13(10):1688-97. Available from: https://doi.org/10.21475/ajcs.19.13.10.p1981
  » https://doi.org/10.21475/ajcs.19.13.10.p1981
• Pinto MAB, Basso CJ, Kulczynski SM, Bellé C. Productivity and physiological quality of seeds with burn down herbicides at the pre harvest of bean crops. J Seed Sci. 2014;36(4):384-91. Available from: https://doi.org/10.1590/2317-1545v36n4997
  » https://doi.org/10.1590/2317-1545v36n4997
• Raimondi RT, Constantin J, Mendes RR, Oliveira Junior RS, Rios FA. Glyphosate-resistant sourgrass management programs associating mowing and herbicides. Planta Daninha. 2020;38:1-11. Available from: https://doi.org/10.1590/S0100-83582020380100033
  » https://doi.org/10.1590/S0100-83582020380100033
• Ramires AC, Constantin J, Oliveira Júnior RS, Guerra N, Alonso DG, Raimondi MA. [Glyphosate associated with other herbicides for control of Commelina benghalensis and Spermacoce latifolia]. Semina Cienc Agrar. 2011;32(3):883-95. Portuguese. Available from: https://doi.org/10.5433/1679-0359.2011v32n3p883
  » https://doi.org/10.5433/1679-0359.2011v32n3p883
• Roberts TR, Dyson JS, Lane MC. Deactivation of the biological activity of paraquat in the soil environment: a review of long-term environmental fate. J Agric Food Chem. 2002;50(13):3623-31. Available from: https://doi.org/10.1021/jf011323x
  » https://doi.org/10.1021/jf011323x
• Rodrigues BN, Almeida FS. [Herbicide guide]. 7th ed. Londrina; 2018. Portuguese.
• Roman ES, Vargas L, Rizzardi MA, Mattei RW. [Resistance of italian ryegrass (Lolium multiflorum) to glyphosate]. Planta Daninha. 2004;22(2):301-6. Portuguese. Available from: https://doi.org/10.1590/S0100-83582004000200018
  » https://doi.org/10.1590/S0100-83582004000200018
• Santos FM, Vargas L, Christoffoleti PJ, Martin TN, Mariani F, Silva DRO.[ Alternative herbicides to control Conyza sumatrensis (Retz.) E. H. Walker resistant to and EPSPs inhibitors]. Rev Ceres. 2015;62(6):531-8. Portuguese. Available from: https://doi.org/10.1590/0034-737X201562060004
  » https://doi.org/10.1590/0034-737X201562060004
• Santos Junior A, Freitas FCL, Santos IT, Silva DC, Paixão GP, Sediyama CS. Management of Commelina benghalensis with saflufenacil in shaded environments. Planta Daninha. 2019;37:1-8. Available from: https://doi.org/10.1590/S0100-83582019370100051
  » https://doi.org/10.1590/S0100-83582019370100051
• Sarangi D, Stephens T, Barker AL, Patterson EL, Gaines TA, Jhala AJ. Protoporphyrinogen oxidase (PPO) inhibitor–resistant waterhemp (Amaranthus tuberculatus) from Nebraska is multiple herbicide resistant: confirmation, mechanism of resistance, and management. Weed Sci. 2019;67(5):510-20. Available from: https://doi.org/10.1017/wsc.2019.29
  » https://doi.org/10.1017/wsc.2019.29
• Sartori F, Vidrio E. Environmental fate and ecotoxicology of paraquat: a California perspective. Toxicol Environ Chem. 2018;100(5-7):479-517. Available from: https://doi.org/10.1080/02772248.2018.1460369
  » https://doi.org/10.1080/02772248.2018.1460369
• Schneider T, Vargas L, Agostinetto D. Alternative control of ryegrass biotypes resistants to clethodim. Rev Bras Herb. 2015;14(3):243-7. Available from: https://doi.org/10.7824/rbh.v14i3.424
  » https://doi.org/10.7824/rbh.v14i3.424
• Sharpe SM, Boyd NS. Utility of glufosinate in postemergence row middle weed control in Florida plasticulture production. Weed Technol. 2019;33(3):495-502. Available from: https://doi.org/10.1017/wet.2019.6
  » https://doi.org/10.1017/wet.2019.6
• Silva JN, Costa EM, Pereira LS, Gonçalves ECZ, Zuchi J, Jakelaitis A. Cowpea yield and quality after application of desiccating herbicides. J Seed Sci. 2020;42:1-11. Available from: https://doi.org/10.1590/2317-1545v42228204
  » https://doi.org/10.1590/2317-1545v42228204
• Silva PV, Barbosa GC, Ferrari A, Tronquini SM, Monquero PA. Chemical control strategies of Commelina benghalensis in coffee crop. Coffee Sci. 2019;14(2):231-9.
• Silva WT, Karam D, Vargas L, Silva AF. Alternatives of chemical control for sourgrass (Digitaria insularis) on maize crop. Rev Bras Milho Sorgo. 2017;16(3):578-86. Available from: https://doi.org/10.18512/1980-6477/rbms.v16n3p578-586
  » https://doi.org/10.18512/1980-6477/rbms.v16n3p578-586
• Soltani N, Blackshaw RE, Gulden RH, Gillard CL, Shropshire C, Sikkema PH. Desiccation in dry edible beans with various herbicides. Can J Plant Sci. 2013;93(5):871-7. Available from: https://doi.org/10.4141/cjps2013-061
  » https://doi.org/10.4141/cjps2013-061
• Soltani N, Shropshire C, Sikkema PH. Glyphosate-resistant Canada fleabane control with three-way herbicide tankmixes in soybean. Am J Plant Sci. 2020;11(9):1478-86. Available from: https://doi.org/10.4236/ajps.2020.119107
  » https://doi.org/10.4236/ajps.2020.119107
• Tahmasebi BK, Alebrahim MT, Roldán-Gómez RA, Silveira HM, Carvalho LB, Alcántara-de la Cruz R et al. Effectiveness of alternative herbicides on three Conyza species from Europe with and without glyphosate resistance. Crop Prot. 2018;112:350-5. Available from: https://doi.org/10.1016/j.cropro.2018.06.021
  » https://doi.org/10.1016/j.cropro.2018.06.021
• Takano HK, Beffa R, Preston C, Westra P, Dayan FE. Glufosinate enhances the activity of protoporphyrinogen oxidase inhibitors. Weed Sci. 2020a;68(4):324-32. Available from: https://doi.org/10.1017/wsc.2020.39
  » https://doi.org/10.1017/wsc.2020.39
• Takano HK, Melo MS, Lopez-Ovejero RF, Westra PH, Gaines TA, Dayan FE. Trp2027Cys mutation evolves in Digitaria insularis with cross-resistance to ACCase inhibitors. Pest Biochem Physiol. 2020b;164:1-6. Available from: https://doi.org/10.1016/j.pestbp.2019.12.011
  » https://doi.org/10.1016/j.pestbp.2019.12.011
• Takano HK, Oliveira Júnior RS, Constantin J, Braz GBP, Gheno EA. Goosegrass resistant to glyphosate in Brazil. Planta Daninha. 2017;35:1-9. Available from: https://doi.org/10.1590/S0100-83582017350100013
  » https://doi.org/10.1590/S0100-83582017350100013
• Tamano H, Nishio R, Morioka H, Furuhata R, Komata Y, Takeda A. Paraquat as an environmental risk factor in Parkinson’s disease accelerates age-related degeneration via rapid influx of extracellular Zn 2+ into Nigral dopaminergic neurons. Mol Neurobiol. 2019;56(11):7789-99. Available from: https://doi.org/10.1007/s12035-019-01642-5
  » https://doi.org/10.1007/s12035-019-01642-5
• Tangamornsuksan W, Lohitnavy O, Sruamsiri R, Chaiyakunapruk N, Norman Scholfield C, Reisfeld B et al. Paraquat exposure and Parkinson’s disease: a systematic review and meta-analysis. Arch Environ Occup Health 2019;74(5):225-38. Available from: https://doi.org/10.1080/19338244.2018.1492894
  » https://doi.org/10.1080/19338244.2018.1492894
• Toledo MZ, Cavariani C, França Neto JDB. [Physiological quality of soybean seeds harvested at two periods after glyphosate desiccation]. Rev Bras Sem. 2012;34(1):134-42. Available from: https://doi.org/10.1590/S0101-31222012000100017
  » https://doi.org/10.1590/S0101-31222012000100017
• Travlos IS, Chachalis D. Glyphosate-resistant hairy fleabane (Conyza bonariensis) is reported in Greece. Weed Technol. 2010;24(4):569-73. Available from: https://doi.org/10.1614/WT-D-09-00080.1
  » https://doi.org/10.1614/WT-D-09-00080.1
• Trusler CS, Peeper TF, Stone AE. Italian ryegrass (Lolium multiflorum) management options in winter wheat in Oklahoma. Weed Technol. 2007;21(1):151-8. Available from: https://doi.org/10.1614/WT-06-038.1
  » https://doi.org/10.1614/WT-06-038.1
• Tsai WT. Status of herbicide use, regulatory management and case study of paraquat in Taiwan. Environ Dev Sustain. 2020;22(3):2673-83. Available from: https://doi.org/10.1007/s10668-018-0293-x
  » https://doi.org/10.1007/s10668-018-0293-x
• Ulguim AR, Vargas L, Agostinetto D, Magro TD, Westendorff NR, Holz MT. [Management of goose grass on transgenic soybean, resistant to glyphosate]. Pesq Agropec Bras. 2013;48(1):17-24. Portuguese. Available from: https://doi.org/10.1590/S0100-204X2013000100003
  » https://doi.org/10.1590/S0100-204X2013000100003
• Underwood MG, Soltani N, Hooker DC, Robinson DE, Vink JP, Swanton CJ et al. The addition of dicamba to POST applications of quizalofop-p-ethyl or clethodim antagonizes volunteer glyphosate-resistant corn control in dicamba-resistant soybean. Weed Technol. 2016;30(3):639-47. Available from: https://doi.org/10.1614/WT-D-16-00016.1
  » https://doi.org/10.1614/WT-D-16-00016.1
• Van Wely AC, Soltani N, Robinson DE, Hooker DC, Lawton MB, Sikkema PH. Control of glyphosate and acetolactate synthase resistant common ragweed (Ambrosia artemisiifolia L.) in soybean (Glycine max L.) with preplant herbicides. Am J Plant Sci. 2014;5(26):3934. Available from: https://doi.org/10.4236/ajps.2014.526412
  » https://doi.org/10.4236/ajps.2014.526412
• Vargas L, Schneider T, Agostinetto D, Bianchi MA. Geographic distribution of ryegrass resistent to the clethodim herbicide in Rio Grande do Sul. Planta Daninha. 2016;34(2):365-76. Available from: https://doi.org/10.1590/S0100-83582016340200018
  » https://doi.org/10.1590/S0100-83582016340200018
• Vidal RA, Portes ES, Lamego FP, Trezzi MM. Eleusine indica resistance to ACCase inhibitors. Planta Daninha. 2006;24:163-71. Available from: https://doi.org/10.1590/S0100-83582006000100021
  » https://doi.org/10.1590/S0100-83582006000100021
• Vilela XS, Medeiros FCL, Gonçalves AH, Silva LC. Quizalofop-p-ethyl controlling sourgrass (Digitaria insularis) and goosegrass (Eleusine indica) in infested coffee areas. Coffee Sci. 2019;14(4):530-7.
• Vink JP, Soltani N, Robinson DE, Tardif FJ, Lawton MB, Sikkema PH. Glyphosate-resistant giant ragweed (Ambrosia trifida L.) control with preplant herbicides in soybean [Glycine max (L.) Merr.]. Can J Plant Sci. 2012;92(5):913-22. Available from: https://doi.org/10.4141/cjps2012-025
  » https://doi.org/10.4141/cjps2012-025
• Vitorino HS, Martins D, Costa SIA, Marques RP, Souza GSF, Campos CF. [Effectiveness of herbicides on weed control in castor beans]. Arq Inst Biol. 2012;79(1):127-31. Portuguese.
• Webster EP, Rustom SY, McKnight BM, Blouin DC, Teló GM. Quizalofop-p-ethyl mixed with synthetic auxin and ACCase-inhibiting herbicides for weed management in rice production. Int J Agron. 2019;2019:1-8. Available from: https://doi.org/10.1155/2019/6137318
  » https://doi.org/10.1155/2019/6137318
• Wehtje G, Altland JE, Gilliam CH. Interaction of glyphosate and diquat in ready-to-use weed control products. Weed Technol. 2008;22(3):472-6. Available from: https://doi.org/10.1614/WT-07-181.1
  » https://doi.org/10.1614/WT-07-181.1
• Wiles TL, Hayward DM. The principles and practice of weed control for notillage soyabean in southern brazil using the bipyridyl herbicide. Trop Pest Manag. 1981;27(3):388-400. Available from: https://doi.org/10.1080/09670878109413810
  » https://doi.org/10.1080/09670878109413810
• Zagonel, J. Herbicide application timing in preharvest desiccation of soybean cultivars with different growth habits. J Environ Sci Health B. 2005;40(1):13-20. Available from: https://doi.org/10.1081/pfc-200034198
  » https://doi.org/10.1081/pfc-200034198
• Zimmer M, Young BG, Johnson WG. Herbicide programs utilizing halauxifen-methyl for glyphosate-resistant horseweed (Conyza canadensis) control in soybean. Weed Technol. 2018;32(6):659-64. Available from: https://doi.org/10.1017/wet.2018.60
  » https://doi.org/10.1017/wet.2018.60
• Zobiole LHS, Krenchinski FH, Pereira GR, Rampazzo PE, Rubin RS, Lucio FR. Management programs to control Conyza spp. in pre-soybean sowing applications. Planta Daninha. 2018;36:1-8. Available from: https://doi.org/10.1590/S0100-83582018360100076
  » https://doi.org/10.1590/S0100-83582018360100076
• Zobiole LHS, Pereira VGC, Albrecht AJP, Rubin RS, Adegas FS, Albrecht LP. Paraquat resistance of Sumatran fleabane (Conyza sumatrensis). Planta Daninha. 2019;37:1-8. Available from: https://doi.org/10.1590/S0100-83582019370100018
  » https://doi.org/10.1590/S0100-83582019370100018
• Zuffo A, Aguilera JG, Carvalho ER, Teodoro PE. Harvest times with chemical desiccation and the effects on the enzymatic expression and physiological quality of soybean seeds. Rev Caatinga. 2020;33(2):361-70. Available from: https://doi.org/10.1590/1983-21252020v33n209rc
  » https://doi.org/10.1590/1983-21252020v33n209rc

• Funding
  This research received no external funding.

Edited by

Approved by:

Editor in Chief: Carol Ann Mallory-Smith

Associate Editor: Carlos Eduardo Schaedler

Publication Dates

• Publication in this collection
  29 July 2022
• Date of issue
  2022

History

• Received
  12 May 2021
• Accepted
  17 May 2022