Selectivity and Effectiveness of Herbicides in the Grain Sorghum Crop

Pimentel, Guilherme Vieira; Guimarães, D.F.; Moreira, Silvino Guimarães; Ávila, M.O.T.; Martins, Inara Alves; Bruzi, Adriano Teodoro

doi:10.1590/s0100-83582019370100069

Cited by 7 publications

(6 citation statements)

References 10 publications

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“…Galon et al (2016) observed that the herbicide s-metolachlor, when applied solely in a pre-emergence or ready-mix form with atrazine promoted morphological changes in sweet sorghum cultivars, causing tissue swelling and young stem curling, and leading to reduced growth and a failure in the final stand of the crop. This is probably due to the main effect of s-metolachlor occurring at the beginning of plant development, as it is absorbed in the coleoptile region of grasses and in the hypocotyl of dicotyledons (Pimentel et al, 2019). Cottingham and Hatzios (1992) observed the slow growth of maize seedlings in the case of prolonged contact time between the coleoptile and the soil treated with metolachlor.…”

Section: Resultsmentioning

confidence: 99%

“…Moore and Locke (2012) found significant reductions in the root growth of Typha latifolia (L.) which had been subjected to s-metolachlor + atrazine. In sorghum hybrids, reductions of up to 69% in plant stand were caused by the pre-emergence application of s-metolachlor + atrazine (Pimentel et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

“…S-metolachlor belongs to the acetamide group (K3) and is formed by two R isomers and two S isomers, which are present in equal proportions in the herbicide, with the S isomer having a higher herbicidal activity than the R isomer (Lowry et al, 2013). The use of s-metolachlor is noteworthy, mainly with regard to its effectiveness in controlling Commelia benghalensis L. (Pimentel et al, 2019). This herbicide can inhibit the synthesis of proteins, chlorophyll and very long chain fatty acids, in addition to interfering with cell division, thereby inhibiting the growth of target plants (Lowry et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

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Image-based modelling of the effect of s-metolachlor plus atrazine on the soaking kinetics of maize seeds

Santos¹,

Silva²,

Santos³

et al. 2022

Int. Agrophys.

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A b s t r a c t. Pre-emergent herbicides can have negative effects on maize seeds. The objective of this study was to model seed soaking curves through the processing of red-green-blue imagery of maize seeds under the influence of concentrations of s-metolachlor + atrazine on both the soaking kinetics and primary root emission. Seeds were placed to soak for 114 h in Petri dishes containing aqueous solutions of a herbicide containing s-metolachlor (290 g l -1 ) + atrazine (370 g l -1 ) with the following concentrations: 0% (water only), 2, 5, 10, 20 and 50%, based on the recommended dose (4.0 l of the commercial product per hectare). The images were systematically taken from a flatbed scanner with artificial light control. The red excess index was adapted to improve image segmentation. From the binary masks applied, the soaking curves for each herbicide concentration were obtained using estimates of seed intumescence over time. The soaking curves were described by fitting Peleg's model. The herbicide concentration has significant effects on both the absorption rate and primary root emission; the absorption rate was reduced by 50%. A concentration of s-metolachlor (290 g l -1 ) + atrazine (370 g l -1 ) in aqueous solution that is above 20% can fully inhibit seed germination.K e y w o r d s: imbibition curve; Zea mays; herbicide; image processing.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Image-based modelling of the effect of s-metolachlor plus atrazine on the soaking kinetics of maize seeds

Santos¹,

Silva²,

Santos³

et al. 2022

Int. Agrophys.

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“…Herbicide sensitivity greatly vary among crops. Nontarget species, such as vetch, clover, and bean, are sensitive (Palhano, Norsworthy, & Barber, 2018), while sorghum is tolerant to atrazine in the soil (Pimentel et al., 2019).…”

Section: Introductionmentioning

confidence: 99%

Atrazine toxicity to Handroanthus heptaphyllus, a nontarget species from a Brazilian biome threatened by agriculture

Silva

Costa

Megguer

et al. 2021

Environmental Quality Mgmt

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The economic basis of the Brazilian midwest is agriculture, concentrating most of the grain production in the country. With the purpose of increasing yield, farmers have intensified land use and the use of atrazine among other pesticides, which can supposedly compromise human health and photosynthetic metabolism of plant species from Cerrado, such as Handroanthus heptaphyllus. The aim of this study was to determine experimentally the sensitivity level of H. heptaphyllus to atrazine, by measuring gas exchange, chlorophyll a fluorescence, chloroplastidic pigments, and membrane permeability. The experiment was conducted in a factorial scheme. Nine‐month‐old H. heptaphyllus plants were treated with six realistic doses of atrazine: 0, 25, 50, 100, 200, and 400 g a.i. ha–1 (corresponding to 10, 20, 40, 80, and 100% of the commercial dose recommended for corn crops, respectively), with five replications. Evaluations were performed at 12, 36, 84, 180, and 276 h after treatment application. Photosynthesis, the effective quantum yield of photosystem II, and electron transport rate were gradually reduced by the action of atrazine. On the other hand, the nonphotochemical quenching increased gradually, which indicates that this mechanism was not sufficient to avoid oxidative stress and cellular damage in H. heptaphyllus treated plants. Based on these results, we concluded that the action of the herbicide in the photosynthetic reduction occurs by the electron transport rate limitation. Therefore, H. heptaphyllus trees are at risk in Cerrado areas next to agricultural lands.

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“…Due to the inherent difficulties, in the chemical control of sourgrass, and taking into account the scarcity of herbicides registered for sorghum (Pimentel et al, 2019)…”

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confidence: 99%

Interference of Increasing Densities of Sourgrass in Grain Sorghum

Cruvinel

Braz

Simon

et al. 2021

RBMS

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Sourgrass has a high competitive potential, resulting in yield losses of several crops. With the increase of grain sorghum cultivation in the Cerrado, mainly in the second crop, studies are needed to assess the interference of sourgrass on this crop. The objective of this work was to evaluate the interference of increasing densities of sourgrass on the sorghum crop under Cerrado conditions. The field experiment was carried out in a randomized block design, with four replications. Five treatments, composed of densities of 0, 2, 4, 6, and 8 sourgrass plants per m -2 , were evaluated. To simulate the densities of sourgrass, this species was planted in the predecessor crop (soybean) according to the predicted density in each experimental unit, and later, at the time of sowing the sorghum, the sourgrass plants, which were clogged, were cut, in order to simulate the condition provided by mechanized harvesting. During the evaluation of the effect of the treatments on the sorghum crop, the stand and plant height, stalk diameter, panicle length, mass of 100 grains, and yield were measured. The increase in sourgrass density, in coexistence with sorghum, negatively affects all vegetative and reproductive parameters evaluated in the crop. For each sourgrass plant m -2 , in coexistence with sorghum, there was a reduction in yield equivalent to 445 kg ha -1 . The maximum reduction in sorghum yield observed was 87%, in a condition in which the crop was developed in coexistence at the density of 8 sourgrass plants m -2 .

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Selectivity and Effectiveness of Herbicides in the Grain Sorghum Crop

Cited by 7 publications

References 10 publications

Image-based modelling of the effect of s-metolachlor plus atrazine on the soaking kinetics of maize seeds

Image-based modelling of the effect of s-metolachlor plus atrazine on the soaking kinetics of maize seeds

Atrazine toxicity to Handroanthus heptaphyllus, a nontarget species from a Brazilian biome threatened by agriculture

Interference of Increasing Densities of Sourgrass in Grain Sorghum

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