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It has been difficult to control Eleusine indica (L.) Gaertn and Spermacocea latifolia Aubl. in cotton and soybean crops due to their herbicide resistance or tolerance to glyphosate. Thus, this study's objective was to evaluate the herbicide efficacy applied in pre-emergence, associated with desiccant herbicide in sequential application, in these species. The experiments for S. latifolia and E. indica were conducted separately in a greenhouse. The experimental design was completely randomized, with 4 replications, in a 6 x 3 factorial. The first factor consisted of pre-emerging herbicides applied two days after the sowing of each species, diclosulam (35 g a.i./ha), s-metolachlor (600 g a.i./ha), pyroxasulfone (200 g a.i./ha) + flumioxazin (200 g a.i./ha), diuron (2000 g a.i./ha), trifluralin (600 g a.i./ha), and the treatment without herbicide. The second factor consisted of the application of diquat (200 g a.i./ha), ammonium glufosinate (400 g a.i./ha), or the absence of sequential application. The results revealed that only for the diclosulam herbicide a sequential application with desiccants was necessary for an effective control of E. indica. The other herbicide applied in pre-emergence showed high efficacy (> 90%) in E. indica control when applied individually. Regarding S. latifolia chemical control, the herbicides s-metolachlor (80.04%), pyroxasulfone + flumioxazin (100%), diclosulam (82.08%) and diuron (89.58%), applied in pre-emergence, presented a satisfactory control at 42 days after emergence. The sequential applications promoted better control of S. latifolia to trifluralin and diuron. In conclusion, there are pre-emergence options for the effective control of E. indica and S. latifolia. However, sequential application can be an important tool for improving the control of some weed species, such as those studied in this work, by certain herbicides.

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ABSTRACT: In order to study alternative ways of control of Dermatobia hominis fly larvae, three processes were tested: T1, cypermethrin 5% + chlorpyrifos 7% + citronellal 0.5% (Pour on); T2, trichlorfon powder dissolved at 2% in burnt oil passed on the nodules; T3, manual larva extraction. The study was conducted at Instituto de Zootecnia in Nova Odessa, São Paulo State, Brazil. In a dairy herd of 176 animals, 29 with at least one larvae were found, distributed in the three treatments. Each treatment’s efficacy percentage was based on the number of live botflies present after 14 days. The animals were observed on days +4, +7, +14 and +21, and new botflies and abscesses were annotated. All treatments presented high effectiveness (above 98%). New botflies were already seen in the first week after applying the three treatments, and on day 21, two abscesses in each chemical treatment were observed. Larva extraction was 100% effective, with no originating abscesses, and should be encouraged in small and medium-sized properties and those with resistant botflies to chemical products.

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This work was carried out with the objective of check the resistance of populations of Digitaria insularis to the herbicide glyphosate in the municipalities of Jaboticabal and Itápolis (SP). The experiment was carried out in a greenhouse, in a 2 x 7 factorial scheme, in a randomized block design was used, with four replications. Were evalueted two populations of Digitaria insularis and seven doses of glyphosate (0D, 1/4D, 1/2D, D, 2D, 4D and 8D, where D is the recommended dose of 450 g ha-1 of acid equivalent). Visual evaluations of control were evaluated at 5, 10, 15 and 20 days after herbicide application (DAA), and, at the end, the dry mass of the plants. The control and fresh weight reduction estimates were fitted to a non-linear log-logistic regression model and the I50, I80 and RF of the populations were calculated. The highest control scores were achieved 20 days after application and the highest amounts of dry mass were from treatments with lower doses. The two populations of Digitaria insularis, from Jaboticabal and Itápolis, were considered to have low resistance to the herbicide glyphosate, indicating the existence of selection pressure for the herbicide glyphosate. [ABSTRACT FROM AUTHOR]

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ABSTRACT In view of the increase in the infested areas and the difficulty in controlling Chamaesyce hirta (L.) Millsp (garden spurge) there is growing interest in identifying herbicides that can be applied in pre and post-emergence, helping to reduce infestation and to provide species control. The objective of this work was to evaluate efficient alternatives of herbicides applied in pre and post emergence aiming at the control of Chamaesyce hirta. Three experiments were carried out in a greenhouse in a completely randomized design with four replications. The first with the application of herbicides in pre-emergence, the second with the application of herbicides in post-emergence when the plants of C. hirta had two to four true leaves fully expanded, and the third experiment, also with the post-emergence application at the flowering and branching stage of the plants. For herbicides applied in pre-emergence, at 28 days after application (DAA), all herbicides evaluated were considered effective for the control of Chamaesyce hirta, showing results above 90%. Several herbicides were efficient in controlling the species with two to four leaves, however, in the flowering stage, there is greater difficulty in control, showing the importance of the plant stage at the time of application.

In this study, we evaluated the effectiveness of insecticides sprayed by contact as well as seeds treatment for controlling the burrower bug Cyrtomenus mirabilis (Perti, 1830) (Hemiptera: Cydnidae) under laboratory conditions. In the first experiment, the insecticides were sprayed onto the insects (direct contact). Insect mortality evaluation started 24h after insecticide application and repeated every two days up to 20 days. In the second experiment, peanut seeds were treated with insecticides. The mortality of insects was evaluated at 10, 15, and 20 days after installation. The mixture of fipronil and alpha-cypermethrin in direct contact was the most efficient treatment to control nymphs and adults of C. mirabilis. Regarding the seed treatment, fipronil was the most efficient for controlling adults of C. mirabilis while for nymphs, all insecticides were highly effective.

Abstract The objective was to evaluate the residual action of the insecticides acetamiprid + etofenprox, spinetoram, indoxacarb and methoxyfenozide on the predator Chrysoperla externa Hagen, 1861 (Neuroptera: Chrysopidae). The bioassays followed the methodologies proposed by the International Organization for Biological and Integrated Control (IOBC). The insecticides were sprayed on grapevine plants cv. Burgundy, using the maximum recommended field dosage for fruit trees. Larvae and adults of the predator were exposed to leaves containing the insecticide residues, at 3, 10, 17, 24 and 31 days after spraying, to determine the residual effect on the following biological parameters: mortality, fecundity and fertility. Based on the toxicity observed during the bioassays, the insecticides were classified according to the IOBC persistence scale. Spinetoram was classified as moderately persistent to larvae and slightly persistent to adults, indoxacarb also he was consideredpersistent for larvae and as a short-lived for the adult stage of the lacewing, thus showing the difference in susceptibility between the stages of development of C. externa. The insecticides acetamiprid + etofenprox and methoxyfenozide are the most suitable for ecologically safe application, in areas where the predator occurs because they are classified as short-lived insecticides for the larval and adult stages of C. externa.

Copyright of Diversitas Journal is the property of Diversitas Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this work isw to evaluate the isolated and combined effect of two biofertilizers (Vitaflex and Maxfert) and a low-toxicity nematicide (fluensulfone) in the management of Meloidogyne exigua in arabica coffee in a cultivated field in the region of Iúna, southern Espírito Santo. The experimental design was randomized blocks, with 9 treatments and four replications. Each experimental unit consisted of 8 plants and the evaluation was carried out in the six central plants. The following treatments were tested: T1- Control (negative control); T2- Rugby (15 L/ha) (Positive control); T3-Nimitz (1.0 L/ha); T4- Vitaflex (10 L/ha); T5- Maxfert (20 L/ha); T6- Vitaflex 10 L/ha + Nimitz (1.0 L/ha); T7- Maxfert 20 L/ha + Nimitz 1.0 L/ha; T8- Vitaflex 10 L/ha + Maxfert 20 L/ha; and T9- Vitaflex 10 L/ha + Maxfert 20 L/ha + Nimitz 1.0 L/ha. Each product was applied following the respective technical recommendations. Before starting the experiment, soil and roots were collected to quantify the initial population of M. exigua present in the area. At 45 days, soil and root samples were taken from 0 cm to 30 cm deep in the rhizosphere region, totaling 1 kg of soil and 200 g of roots for each sample. These were identified and packed in plastic bags for processing, extraction and quantification of juvenile M. exigua. The extraction of nematodes from the soil was carried out according to the method of Jenkins (1964) and from the roots by the technique of Hussey and Barker (1973), as modified by Bonetti and Ferraz (1981). To meet the ANOVA assumptions, the data were transformed to x-1 and analyzed using the R statistical software. The means of the data were compared by the Scott-Knott test at 5% probability (R Development Core Team, 2009). All treatments reduced the number of M. exigua in the root system and the soil. The isolated application of Nimitz, Vitaflex, and Maxfert caused a greater reduction of the nematode population in the roots, while the isolated application of Maxfert and the combination between Vitaflex + Maxfert promoted greater reduction of the nematodes in the soil The combination between Vitaflex + Nimitz and Maxfert + Nimitz also presented satisfactory results in comparison with the control, indicating the good potential of the combined use nematicides and biofertilizers for the management M. exigua. We conclude that both the isolated and associated use of chemical and biological nematicides proved to be efficient in reducing the population of M. exigua in arabica coffee grown in the field. This information strengthens the possibility of managing this pathogen, which in some cases has been causing large damages to this crop.

ABSTRACT Droplet size is one of the most important factors that affect spray deposition and weed control through the use of herbicides. The aim of this study was to evaluate the influence of the droplet size on the spray deposition and control of Euphorbia heterophylla and Urochloa ruziziensis by using glyphosate. The treatments included spraying glyphosate with fine, medium, coarse, very coarse, and ultra-coarse droplet sizes to determine the deposition, uniformity of distribution, visual control, and dry weight reduction (DWR). The treatments were compared with the values of the dose required to achieve 50% DWR or 50% visual control (C50) at 7, 14, 21, and 28 days after herbicide application. Fine and medium droplet sizes afforded high deposition values and low distribution uniformities in E. heterophylla . Fine and medium droplet sizes yielded the lowest C50 on visual control and DWR in E. heterophylla, respectively. The droplet size did not affect the spray deposition on U. ruziziensis plants; however, the larger droplets had less uniformity of distribution. In U. ruziziensis plants, spraying glyphosate with coarse and medium droplet sizes yielded the lowest values of C50 to visual control and DWR, respectively.

Abstract The objective of this work was to evaluate different chemical treatments, associating herbicide combinations with the maintenance of forage species in the off-season, for the management of glyphosate-resistant sourgrass (Digitaria insularis) in a soybean crop. The experimental design was a randomized complete block in a 4×5 split-plot arrangement, with four replicates. The treatments consisted of: four combinations of the clethodim, glyphosate, haloxyfop-p-methyl, glufosinate ammonium, and s-metolachlor herbicides in the plots; green covers with the Massai, BRS Tamani, and BRS Zuri cultivars of Panicum maximum and with Urochloa ruziziensis, as well as fallow, in the subplots; and a control with the isolated application of glyphosate at the desiccation and post-emergence of the soybean crop infested with sourgrass and weeded. The herbicides tested before sowing and at post-emergence of soybean promoted a control above 90% of adult sourgrass plants until grain harvest. After harvest, there was a new emergence of sourgrass, mainly in the plots without green cover in the off-season. Overseeding soybean with forage species allowed of the establishment of these plants, which consequently interfered in sourgrass emergence and growth. The chemical treatments with herbicide combinations associated with the maintenance of forage species in the off-season are effective for the control of adult glyphosate-resistant sourgrass plants.

ABSTRACT The use of ultra-coarse droplets for herbicide application reduces the risk of drift but may compromise the coverage and efficacy of the treatment. The objective of this work was to evaluate the use of ultra-coarse droplets, in different spray volumes, in the application of dicamba herbicide in association with glyphosate, for the control of weeds in two field trials. The first trial was conducted in a 5 x 2 factorial design, with five spray volumes (58, 72, 96, 144, and 177 L ha-1) and two air induction flat-fan spray tips (MUG 110015 - MagnoJet and TTI 110015 - Teejet). The control efficiency of Commelina benghalensis and the spray deposition on the target were evaluated by detecting a tracer using spectrophotometry. The second was conducted in a 2 x 2 factorial scheme, using two volumes (100 and 125 L ha-1) and two tips (MUG 11002 and TTI 11002). The control efficiency of Conyza spp. and fresh matter were evaluated. The different spray volumes and tips did not differ in relation to the deposition of the tracer. The use of ultra-coarse droplets was adequate for weed control. The TTI and MUG tips gave similar and adequate control performance starting at 96 L ha-1. Increasing the volume above 100 L ha-1 did not result in better control.

Abstract This review paper presents the current context of wheat production in Brazil, the management strategies to reduce yield losses due to blast, and the biotechnological approaches to improve wheat resistance. Wheat blast or brusone is caused by the Magnaporthe oryzae Triticum (MoT) pathotype fungus that can infect all the aboveground parts of the plant. The main symptom of the blast disease is spike bleaching that impairs grain production, causing yield losses up to 100% in susceptible wheat cultivars. The first world report of blast in wheat spikes was in Brazil, in 1985, and, currently, the disease is the main constraint to wheat cultivation in tropical and subtropical areas of the Cerrado and Mata Atlântica biomes. For a long time, the use of fungicides has been found to be ineffective under high-pressure disease conditions. However, recent works have pointed out that fungicide efficiency depends on the integration of other control measures, particularly the choice of cultivars with moderate resistance. In this review paper, the high variability of wheat reaction to MoT is presented, as well as a panel of resistant or moderately resistant cultivars (including non-2NS carriers), promptly available for cultivation in regions where blast is endemic.

ABSTRACT: The study evaluated the efficacy and soybean spectral responses to fifteen foliar fungicide mixtures labeled to control Asian soybean rust. Canopy level reflectance was measured using a multispectral camera onboard a multirotor drone before and two hours after each spray. The third application of fungicides improved control of soybean rust and increased yield. Nevertheless, up to three consecutive foliar fungicides applications did not affect the reflectance of soybean plants at visible and infrared wavelengths. Thus, drones can be a viable strategy for data acquisition regardless of the application of the fungicides.

The predator Eriopis connexa (Germar, 1824) (Coleoptera: Coccinelidae), is an important biological control agent in wheat fields. In this work, we evaluated the lethal effects of fifteen insecticides used in the wheat crop on adults of the predator E. connexa, using the methodology proposed by International Organization for Biological and Integrated Control (IOBC). Sublethal effects have not been evaluated. The insecticides were sprayed on glass plates that were used to set up the exposure arenas. The chitin synthesis inhibitors diflubenzuron SC, diflubenzuron WP, lufenuron, triflumuron, and the pyrethroid beta-cyfluthrin were considered harmless to adults of the predator and should have their use prioritized. On the other hand, methomyl, lambda-cyhalothrin, thiamethoxam + lambda-cyhalothrin A and B were considered harmful to E. connexa and should be avoided when adults of the predator are present in the crop.

ABSTRACT Weed management consists of a fundamental practice in cassava, with mechanical and chemical control widely used. The objective of this work was to evaluate the efficacy of pre-emergence herbicides, as well as to determine the interaction of these with weeding complementation in the weed management in cassava. Two experiments were conducted in Junqueiro (Alagoas). In 2015/16, the experimental design was based on randomized blocks, with treatments distributed in a split-split-plot scheme, with four replications. In the main plot, four pre-emergence associations of clomazone + flumioxazin in different doses were evaluated, in addition to a control without herbicide. In the subplots, the Caravela and Pretinha cassava cultivars were evaluated, while in the sub-subplots the control complementation was evaluated using or not the manual weeding. In the 2016/17, the plot design and layout remained the same as for 2015/16, except for the composition of the herbicide treatments, since the standardization of clomazone dose has been chosen, varying only the doses of flumioxazin. The association of clomazone and flumioxazin has shown efficacy in weed control, with a greater residual as higher doses are used. This association provided higher shoot and root yield. Weeding complementation along the cassava cycle can increase its yield.

ABSTRACT This study evaluated the relationship between the resistance of Lipaphis pseudobrassicae to the parasitoid Diaeretialla rapae and the effects of the insecticide acetamiprid on the aphid. Four groups of L. pseudobrassicae collected in Uberlândia, MG, were used. The first two were formed by individuals of the same clone (C1), which were resistant (C1R) or susceptible (C1S) to the parasitoid. The third group was formed by resistant individuals to the parasitoid descended from a clone collected in canola (C2R) and the fourth group, from a population collected in a commercial plantation of collard greens (P1). Determination of LD50 was done with three replications of 10 aphids, subjected to dose-response assays, with the application of five concentrations of the insecticide acetamiprid (0.01, 0.1, 1, 10 or 100 ng a.i./aphid) and a control treatment consisting of acetone alone. There was no significant difference in the LD50 of individuals of the same clone, C1R and C1S (0.06 ng a.i./aphid for both clones). C2R had the highest LD50 (0.14 ng a.i./aphid), while P1 had the lowest (0.01 ng a.i./aphid). These results suggest that resistance against the parasitoid is not, therefore, associated with the effects of insecticide on L. pseudobrassicae.

ABSTRACT The use of strategies such as sequential applications and mixtures may increase the control spectrum and the residual effect of chemical control of weed in the cassava crop. Thus, the objective was to evaluate the selectivity and efficacy of sequential applications and tank mixture of herbicides in the control of weed in the cassava crop cultivar ‘Baianinha’. The experimental design was of randomized blocks, with eleven treatments and four replicates. The treatments consisted in: harrowed control, control without harrow, clomazone, mesotrione, S-metolachlor, clomazone+S-metolachlor, mesotrione+S-metolachlor, clomazone+mesotrione, sulfentrazone/clomazone, clomazone/[mesotrione+S-metolachlor], S-metolachlor/[mesotrione+clomazone]. The doses used for clomazone, mesotrione, sulfentrazone and S-metolachlor in the single applications, in sequence and in tank mixture were of 1,25, 0,24; 0,6 anf 1,92 kg ha-1, respectively. The first application of the sequential treatments occurred 50 days after planting (DAP) and the second at 92 DAP. The applications of mesotrione, mesotrione+clomazone and mesotrione+S-metolachlor, were carried late, at 92 DAP. Based on the data obtained, it is concluded that the mixture mesotrione+S-metolachlor and the sequential application of clomazone/[mesotrione+S-metolachlor] were selective to cassava ‘Baianinha’ and efficient in the weed control (over 80% up to 148 days after planting).

Asian soybean rust is an aggressive disease and chemical control must be handled assertively to minimize productivity damage. The objective was to evaluate systemic fungicides and multisite mancozeb, combined or not, and the effects on disease control and soybean yield, cv. 'BMX Lança'. The work was conducted in the field in the 2016/17 and 2017/18 crops, in a randomized complete block design, with four replications. The following treatments were evaluated: T+P) trifloxystrobin + prothioconazole; A+B) azoxystrobin + benzovindiflupyr; T+P+MB) trifloxystrobin + prothioconazole + mancozeb; A+B+MB) azoxystrobin + benzovindiflupyr + mancozeb; MB) mancozeb; and Control (without fungicide application). After the occurrence of the first symptoms of the disease, the severity (%) was evaluated in five trifolia per plot, every seven days, making it possible to calculate the area under the disease progress curve (AUDPC). The yield components and productivity (kg ha-1) were also evaluated. In both crops, the combination of systemic fungicides and mancozeb reduced the severity (%) and progress of Asian rust, reaching a control above 81%. Treatment with trifloxystrobin + prothioconazole + mancozeb (T+P+MB) obtained the highest percentages of control (94.5% - 2016/17, and 93.7% - 2017/18) of Asian rust, and provided, in the 2016/17 crop, productivity at 15 sc ha-1, in relation to the fungicide applied alone (T+P). The combination of systemic fungicides and mancozeb, as proposed in this work, reduces the severity and progress of Asian rust and ensures the maintenance of the productive potential of the soybean.

ABSTRACT: Chrysodeixis includens (Walker) and Anticarsia gemmatalis Hübner are important soybean defoliators. The chemical control of A. gemmatalis has been easier and more effective than that of C. includens. It is hypothesized that C. includens is natural tolerant to insecticides. This study quantified and compare the susceptibility of C. includens and A. gemmatalis to the insecticides flubendiamide, methomyl, and spinetoram. A susceptible population of each species, maintained under laboratory conditions without insecticides selection pressure for more than 17 generations, was used. Ingestion bioassays using five to eight concentrations of each insecticide applied on the artificial diet surface were used to estimate the LC50 and LC99 (LC = Lethal Concentration). The tolerance ratio (TR) was calculated by dividing the LC50 or LC99 of the most tolerant species by the respective value of the most susceptible species. Chrysodeixis includens was more tolerant to all insecticides tested than A. gemmatalis, with TR50 values of 45.9-, 10.0- and 2.6-fold for methomyl, flubendiamide, and spinetoram. These findings indicated that the risk of evolution of resistance may be higher for C. includens than A. gemmatalis due to differential survival when exposed to the same dose of insecticide applied in soybean fields. Therefore, to improve the control of both species, integrated pest management (IPM) and insect resistance management (IRM) strategies should be considered to avoid control failures in field conditions.

Abstract Population explosions of the stable fly (Stomoxys calcitrans) have become a serious concern for livestock producers near sugarcane mills in some regions of Brazil due to the insect’s massive reproduction on sugarcane byproducts and waste. Despite the limited efficiency of insecticides for controlling stable fly outbreaks, producers still rely on chemical control to mitigate the alarming infestations in affected areas. This study evaluated the susceptibility of S. calcitrans populations to cypermethrin in the state of Mato Grosso do Sul, Brazil. Stable flies were tested from three field populations and two colonies, established from flies previously collected at sugarcane mills. Wild flies were collected with Nzi traps in areas of sugarcane plantations. Both wild and colonized flies were exposed to eleven concentrations of cypermethrin in impregnated filter paper bioassays. All the populations proved to be resistant to cypermethrin, with resistance factors among field populations ranging from 6.8 to 38.6. The intensive use of insecticides has led to the development of pyrethroid resistance in stable fly populations in the proximities of sugarcane mills in the state of Mato Grosso do Sul.

Abstract Southern cattle tick resistance to pour-on and injectable acaricides has yet to be evaluated on a broader scope, and the paucity of information on the subject may hinder efforts to control this parasite. The objective of this study was to evaluate the resistance profile of ten populations of Rhipicephalus microplus to the acaricides fluazuron, fipronil and ivermectin in cattle herds in Mato Grosso do Sul, Brazil. The larval immersion test (LIT) was used to evaluate susceptibility to ivermectin and fipronil and the adult immersion test (AIT) was performed to evaluate fluazuron. Samples were randomly obtained in ten farms, and in general, we found resistance in five samples to fluazuron and in four samples to ivermectin and fipronil. Six samples showed incipient resistance to ivermectin and fipronil. Five of the ten evaluated samples showed resistance and/or incipient resistance to all the active ingredients, and the other five to two active ingredients. Among the samples classified as resistant, the average resistance ratio for ivermectin was 2.75 and 3.26 for fipronil. These results demonstrate the advanced status of resistance to the most modern chemical groups for the control of R. microplus in the state of Mato Grosso do Sul.

ABSTRACT: Technologies that advocate the use of herbicide-resistant crops are alternatives to weed control, but they may cause oxidative stress and change secondary metabolism of plants. Therefore, this study aimed to evaluate changes in the secondary metabolism of soybean plants which contained Cultivance® (CV), sulfonylurea-tolerant soybean (STS) and Roundup Ready® (RR) technologies submitted to the application of the mixture of herbicides imazapyr and imazapic in “plant-apply” and “apply-plant” management systems. Two field experiments, in which soybean cultivars were submitted to increasing doses of the mixture of herbicides imazapyr and imazapic, were performed. Aerial parts of plants were collected 10 days after crop emergence and stored at -83oC, until quantification of variables. In general, the soybean cultivar BRS382CV exhibited lower contents of chlorophyll than cultivars CD249STS and NA5909RR. Besides, increasing doses of the mixture of herbicides imazapyr and imazapic decreased contents of chlorophyll in the cultivars. Stress caused by herbicides induced more generation of ROS and effective response of the antioxidant system through enzymes SOD, CAT and APX.

ABSTRACT: To examine the effect of pre emergence herbicides, plant extracts and mulches on yield and yield components of maize, a field experiment was carried out at New Developmental Farm, The University of Agriculture Peshawar-Pakistan during summer crop season 2016. Maize variety “Azam” was sown in Randomized Complete Block (RCB) design having four replications and ten treatments i.e. hand weeding, Dual Gold 960 EC (S-metolachlor 1 L ha-1), Stomp 330 EC (pendimethaline 2.5 L ha-1), atrazine 1.25 L ha-1, Eucalyptus camaldulensis L. extract (125 g L-1), Ammi visnaga L. extract (125 g L-1), black plastic mulch, wheat straw mulch, saw dust mulch and weedy check. The data revealed that hand weeding and herbicides significantly affected the weed density (m-2), weeds biomass (kg ha-1), plant height (cm), kernels weight (g), number of kernels ear-1, biological yield (kg ha-1) and grain yield (kg ha-1). All the significant parameters of crop were comparable among the hand weeding, atrazine, S-metolachlor and pendimethaline treated plots. However, atrazine and S-metolachlor proved to be the most economical herbicides giving maximum yield (4636.4 and 4562.8 kg ha-1), respectively. Among plant extracts, E. camaldulensis showed satisfactory results in suppressing weeds and enhancing yield of maize i.e. (3441.6 kg ha-1). Hence, the use of herbicides (atrazine and S-metolachlor) at the recommended rates and hand weeding is recommended for effective weed control and ultimately high yield of maize crop.

ABSTRACT: A new cycle of growth begins after pruning of cassava, and weed control is necessary. Thus, this study aimed to evaluate the selectivity and efficiency of sequential application of herbicides alone and in mixture with and without of foliar fertilizer after pruning of cassava. Two experiments were carried out in a randomized block design with four replications. The treatments of Experiment 1 consisted of control without weeding; control with weeding; mesotrione; mesotrione/mesotrione; mesotrione + foliar fertilizer/mesotrione + foliar fertilizer; mesotrione/mesotrione + foliar fertilizer; mesotrione + clethodim; mesotrione + clethodim + foliar fertilizer/mesotrione + clethodim + foliar fertilizer; mesotrione + clethodim/mesotrione + clethodim; mesotrione + clethodim/chlorimuron; mesotrione + clethodim/chlorimuron + foliar fertilizer; mesotrione + clethodim + foliar fertilizer/chlorimuron + clethodim + foliar fertilizer; mesotrione + clethodim/chlorimuron + clethodim]. Treatments of Experiment 2 consisted of control without weeding; control with weeding; chlorimuron; chlorimuron + foliar fertilizer/chlorimuron + foliar fertilizer; chlorimuron/chlorimuron; chlorimuron + clethodim; chlorimuron + clethodim + foliar fertilizer/chlorimuron + clethodim + foliar fertilizer; chlorimuron + clethodim/chlorimuron + clethodim; chlorimuron + clethodim/mesotrione + foliar fertilizer; chlorimuron + clethodim/mesotrione; chlorimuron + clethodim + foliar fertilizer/mesotrione + clethodim + foliar fertilizer; chlorimuron + clethodim/mesotrione + clethodim. The doses of mesotrione, clethodim, and chlorimuron used in both experiments were 240, 120, and 20 g ha-1, respectively, while 2.5 L of the commercial product Amino Plus® was used as foliar fertilizer. The first application was carried out at 50 days after pruning and the second application at 22 days after the first application. In Experiment 1, the application of mesotrione, mesotrione/mesotrione, and mesotrione + clethodim/mesotrione + clethodim showed selectivity to cassava and were efficient in weed control. In Experiment 2, chlorimuron + clethodim/mesotrione, chlorimuron + clethodim + foliar fertilizer/mesotrione + clethodim + foliar fertilizer, and chlorimuron + clethodim/mesotrione + clethodim were efficient in weed control, but no treatment was selective. The addition of foliar fertilizer to the spray solution did not contribute to increase selectivity.

ABSTRACT: Floriculture and landscaping sector has the same problems as other crops regarding weed management. Weeds affect the yield and quality of the harvested product, in which the visual aspect and aesthetics stand out as the most important factors in flower production and landscaping. Weed control in floriculture and landscaping is critical and costly because maintaining the beauty of the product and the use of herbicides is a low-cost management tool compared to manual management. However, it implies knowing herbicide selectivity, as ornamental species may present some injury depending on the active ingredient and the degree of selectivity of the compound. Because the use of this practice in flower production and landscaping both abroad and mainly in Brazil is incipient, aspects of selectivity, chemical weed control, and safe application of different herbicides are addressed in this paper.

The efficacy of 14 different insecticides was tested for the control of onion thrips Thrips tabaci (Lindeman, 1889) on onion in Itajaí Valley, SC during 2018. The insecticides were sprayed six times at intervals of about seven days, we evaluated the number of nymph of thrips per plant 48 hours after spray, visually rated for thrips damage at 96 DAT and total and commercial onion bulb production. Significant diferences were observed between various insecticides evaluated. The treatments formetanate hydrochloride, spinetoram and abamectin proved the best thrips control, less thrips damage and good total and commercial productivity. The insecticide profenofos + cypermethrin exhibited reduction of thrips nymph and better total and comercial production comparing control however not reduced thrips damages. The insecticides thiacloprid, thiamethoxam + lambda-cyhalotrin, and Imidacloprid reduced the thrips density but had similar results for thrips damages and onion bulb production comparing with control, excepting total productivity for the neonicotinoids thiacloprid and and Imidacloprid.

The present study evaluated the effect of different rates of chlorantraniliprole, chlorantraniliprole + lambda-cyhalothrin, spinosad, and chlorfenapyr on their selectivity for the pupae and adults of Trichogramma pretiosum. The negative effect of majority of the insecticides tested on most of the parasitoids was directly proportional to the rate of the insecticide applied. Chlorantraniliprole at a rate of 10 g a.i. ha-1 was classified as harmless (class 1) to both pupae and adults of the parasitoid. The effect of chlorantraniliprole at a rate of 20 to 50 g a.i. ha-1 varied from harmless (class 1) to slightly harmful (class 2) to the adults of T. pretiosum. Chlorantraniliprole 10 + lambda-cyhalothrin at 5 g a.i. ha-1 was classified as harmless (class 1) to the pupae and moderately harmful (class 3) to the adults of T. pretiosum. On the contrary, the highest rate of chlorantraniliprole 50 + lambda-cyhalothrin tested (i.e., 25 g a.i. ha-1) was classified as slightly harmful (class 2) to the pupae and harmful (class 4) to the adults of the parasitoid. Similarly, increasing the application rate of spinosad and chlorfenapyr also exhibited an increase in toxicity. Spinosad at a rate of 24 g a.i. ha-1 was classified as slightly harmful (class 2) and harmless (class 1) to the pupae and adults of T. pretiosum, respectively. Spinosad at 96 g a.i. ha-1 was classified as both moderately harmful (class 3) and harmful (class 4) to the pupae of the parasitoid. Chlorfenapyr at a rate of 192 g a.i. ha-1 was classified as both slightly harmful (class 2) and moderately harmful (class 3) to the pupae of T. pretiosum, whereas chlorfenapyr at 336 g a.i. ha-1 was categorized as slightly harmful (class 3) and harmful (class 4) to the pupae. These results indicate that an increase in the rate of insecticide affected T. pretiosum negatively. Therefore, higher insecticide rates should only be adopted when strictly necessary to control the target pest, because they might compromise the biological pest control process in the field.

The aim of this study was to evaluate the chemical control of Asian soybean rust (Phakopsora pachyrhizi Syd. & P. Syd.) using different tips and spray nozzles under controlled conditions. Rooted trifolia placed inside an acrylic box containing macronutrients, micronutrients and vitamins were treated with epoxiconazol + pyraclostrobin, ciproconazol + azoxystrobin and tebuconazol fungicides. These fungicides were sprayed at a height of 0.5 m with two knapsack sprayers pressurized with CO2 gas (drop generator in four spray tips spaced by 0.5 m from each other) and another rotating nozzle (drop generator through a rotating nozzle). Untreated trifolia were controls. Water sensitive paper was placed next to each acrylic box to obtain median volume diameter (MVD), number of droplets.cm-2 and coverage (%). Trifolia were inoculated 24 hours after that these were treated with fungicide, using a spore concentration adjusted to 2 x 104 uredospores.mL-1. Then, the number of lesions and uredia.cm-2 in central leaflets were quantified. Lower number of lesions and uredia.cm-2 were observed in leaflets treated with two fungicide mixtures using an AIRMIX 11001 tip. A lower VMD was found in leaflets sprayed with the fungicides azoxystrobin + epoxiconazol and tebuconazol, when compared to the leaflets treated with another mixture. The Asian rust control, as well as the number of droplets.cm-2 and coverage, seems to be dependent on the interactions among fungicides and tips or nozzles.

The use of pesticides in the soybean crop may impair the biological control, if the products are not selective to Telenomus podisi and Trissolcus basalis, which are important stink bug egg parasitoids. This study aimed to assess the selectivity of 15 pesticides registered for soybean crop on adults of T. podisi and T. basalis. Three laboratory bioassays were performed, totaling 18 treatments, in a completely randomized design, with four replications. The insecticides (g or mL of a.i.) imidacloprid + beta-cyfluthrin (0.25 + 0.03), deltamethrin (0.06), thiamethoxam + lambda-cyhalothrin (0.27 + 0.35), acephate (1.87) and fenitrothion (1.25) are harmful to both parasitoids species. Flubendiamide (1.20), diflubenzuron (2.00), Bacillus thuringiensis (0.08) and lufenuron (0.12) are innocuous to both parasitoids. The fungicides azoxystrobin + flutriafol (0.31 + 0.31), trifloxystrobin + prothioconazole (0.37 + 0.44), pyraclostrobin + metconazole (0.33 + 0.12) and trifloxystrobin + cyproconazole (0.94 + 0.40) are innocuous to T. podisi, but slightly harmful to T. basalis. The herbicides glufosinate ammonium salt (0.50) and glyphosate isopropylamine salt (1.20) are innocuous to both parasitoids.

Cercospora leaf spot (CLS) caused by Cercospora beticola Sacc. is controlled by foliar spraying with fungicides following a fixed schedule, without considering the disease progress. A forecasting system can predict the progress of the disease and direct the spraying regime, reducing the number of applications and optimizing the disease management. To evaluate the progress of CLS under the different spraying regimes, the statistical modeling technique known as mixed models was applied. These models include not only fixed effects but also random effects for each individual in the studied population. In the harvest seasons of 2018 and 2019, the spraying regimes used were based on systems with accumulated estimated severity (SE) values of 0.15; 0.25, and 0.35, in addition to standard controls with spraying intervals of five and seven days. The accumulated severity of CLS as a function of time in the five spraying regimes was calibrated with a Gompertz model adjusted by the mixed model and the random effect adjusted to the upper asymptote. As a result of the model calibration, the spraying regime treatment with SE=0.35 did not differ from the standard controls regarding the area under the disease progress curve (AACPD), final severity, and productivity. The data presented in this study demonstrate the efficiency of a forecasting system in CLS management, with the advantage of reducing the number of fungicide sprayings and environmental impact. [ABSTRACT FROM AUTHOR]

Septoria leaf spot is one of the main diseases affecting tomato. Its damages vary according to susceptible cultivar, pathogen physiological races, and environmental conditions. The objectives of this study were to assess the inhibitory concentration of 50% of spores (IC50), the sensitivity reduction factor (SRF) of Septoria lycopersici isolates, and the effectiveness of fungicides traditionally used to control Septoria Leaf Spot (SLS) in tomato in the state of Santa Catarina, Brazil, during the 2016 and 2017 crop seasons. For the in vitro experiment, 13 S. lycopersici isolates were obtained from leaves displaying SLS symptoms from different tomato cultivars. The fungicides thiophanate methyl and mancozeb were evaluated at concentrations of 0.1; 1.0; 10; 100 and 1000 mg L-1 of active ingredient to determine the effective dose for inhibiting 50% of spore germination (DE50) and the sensitivity reduction factor (FRS). The S. lycopersici isolates derived from tomato crops that were sprayed with these fungicides were compared with the isolates 475-1, 475-3, 475-4, and 475-7 obtained from tomato crops that remained unsprayed. For the in vivo experiments, the preventive fungicides azoxystrobin, chlorothalonil, captan, and mancozeb and the curative fungicides thiophanate methyl, mancozeb, difenoconazole, and methconazole were sprayed at the commercial dose at 12, 24, 36, 48, 72, and 96 h before (preventive) and after (curative) the inoculation with the 475-1 S. lycopersici isolate, to evaluate the efficiency of the SLS control in tomato plants. The active ingredient thiophanate methyl and mancozeb were considered non-toxic to all S. lycopersici isolates regardless of the doses tested. The DE50 values of thiophanate methyl and mancozeb rangesd from 75 to 580 mg L-1. The preventive fungicides chlorothalonil and azoxystrobin and curative fungicides difenoconazole and metconazole were significantly efficient to control SLS in vivo. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the efficiency of post-emergence herbicides applied to cowpea. Two trials were conducted in a randomized block with four replicates: in the first test the ready mix [bentazon + imazamox] associated or not with haloxyfop-p-methyl, phenoxaprop-p-ethyl, fluazifop-p-butyl, quizalofop-p-tefuryl, clethodim and tepraloxydim graminicides were tested. In the second trial [bentazon + imazamox], imazethapyr, bentazone + imazethapyr, ethoxysulfuron + bentazon, applied alone or associated with haloxyfop-p-methyl were tested. Non-weed and weeded controls were included as treatments. The mixture of [bentazon + imazamoxi] was selective to BRS Guariba cowpea cultivar BRS Guariba and promoted control of over 90% of Alternanthera tenella, Commelina benghalensis and Nicandra physaloides and did not control Eleusine indica, Cenchrus echinatus and Glycine max (volunteer soy plants). The imazethapyr associated or not to bentazon were selective to the cowpea, but promoted moderate or poor control for A. tenella, C. benghalensis, E. indica, C. echinatus and volunteer soy plants. The application of imazethapyr + bentazon showed excellent control of N. physaloides. Fifty five percent phytotoxicity was observed at 7 days after application of ethoxysulfuron + bentazon (DAA) and partial recovery of symptoms at 28 DAA (16%). However, the cowpea was tolerant to the etoxissulfuron + bentazone herbicides. The mixture of ethoxysulfuron + bentazon promoted control over 87% for N. physaloides and 100% for volunteer soy plants, but deficient (<60%) for A. tenella, E. indica and C. echinatus and moderate (>70%) control for C. benghalensis. For the control of E. indica and C. echinatus it was necessary to use the graminicides. Yields of cowpea on herbicide treatments were similar those obtained in the weed control and higher than the not weeded treatment, in both trials. The reduction of grain yield due to weeds was approximately 60%. [ABSTRACT FROM AUTHOR]

The objective of this work was to assess the effect of acibenzolar-s-methyl, potassium phosphite, potassium silicate, and trifloxystrobin + prothioconazole products on curative control of powdery mildew (Microsphaera diffusa) in soybean. The experimental design was completely randomized, in a single factor scheme, containing five treatments with four replications. The products were applied on leaves at the V4 phenological stage, with disease severity of 5%. At 7, 14, and 21 days after the application of the products (DAA), the incidence and severity of the disease were assessed. The trifloxystrobin + prothioconazole reduced by 30% the disease incidence and 80% disease severity compared to the control. The inhibitory effect of the products on conidia production in vivo and its germination in vitro were also assessed. Trifloxystrobin + prothioconazole was more effective in the reduction of both conidia production and germination. Acibenzolar-s-methyl, potassium phosphite, and potassium silicate reduced conidia germination, but neither affected the disease severity nor the conidia production. Based on this, it can be concluded that the fungicide trifloxystrobin + prothioconazole reduced the production of conidia and inhibited its germination, showing curative and protective effect against soybean powdery mildew and that the resistance inducers tested interfered with pathogen germination, but without significant effect on the disease when applied after the onset of symptoms. [ABSTRACT FROM AUTHOR]

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Os objetivos desse trabalho foram avaliar a eficiência de The aim of this study was evaluate efficacy fungicides to control cercospora leaf spot (Cercospora zeae-maydis) and helminthosporium leaf blight (Exserohilumturcicum), productivity, economic returns and quality of grain of corn culture of second crop in Farm Bandeirantes at Feliz Natal/MT. The treatments evaluated were: pyraclostrobina+epoxiconazol (0,7 L ha-1), trifloxistrobina+protioconazol (0,3L ha-1), azoxistrobina+cyproconazol(0,3 L ha-1), azoxystrobina (0,25 L ha-1), trifloxistrobina+ciproconazol (0,2 L ha-1) and control. Theapplicationof products occurred when corn was with 55 days, with a high propelled sprayer. The experimental design was a randomized block, with 6 treatments and 3 replications. The severity of each disease was visually determined through periodic analyses and ten plants were marked in each repetition, which were evaluated during the entire crop cycle. The data of severity obtained were used to calculate the area under disease progress curve (AUDPC). It was also obtained the production per ha, the economic return (R$ ha-1) and physiological quality of grain was evaluated by germination tests and accelerated aging of the grains. All treatments had significant difference compared to the control sample in controlling cercospora leaf spot about the control of helminthosporiumleat blight, the fungicides trifloxystrobin+prothioconazol and trifloxystrobin+cyproconazol were not efficient, and the fungicides pyraclostrobina+epoxiconazol, azoxystrobina, azoxistrobina+cyproconazol were efficient. The treatments that had major production are from the group of triazoles+strobilurine and the fungicide pyraclostrobin+epoxyconazol showed greater economic viability. Not were differences among fungicides, and neither of the treatments compared to control, in germination and accelerated aging tests, showing that the grains have good quality characteristics

ABSTRACT: The performance of fungicides in controlling Asian soybean rust depends, in part, the spray quality of these products. The market of components to spray offers new types of nozzles which generate droplets with different characteristics. This study aimed to verify whether applications of fungicides with different spray nozzles interfere in soybean rust control. The experiment was conducted in the 2013/2014 harvest. The experimental design was a randomized block with three replications, and compared ten spray nozzles and a control without fungicide application. The applications were made with a backpack sprayer pressurized with CO2, set to apply a spray volume of 150 L ha-1. For the determination of severity four plants per plot were sampled, quantifying in each leaflet the number of uredinia cm-2, which permitted to integrate the area under the disease progress curve (AUDPC). We concluded that HYPRO GUARDIAN® 120015 Single pre orifice flat spray nozzle, that generates medium size of droplets, provided the lowest AUDPC of soybean rust, as well as the use of fungicide reflected in grain yield, which was on average 288% higher than that obtained by the control without fungicide application.

ABSTRACT The objective of this research was to confirm the resistance of a barnyardgrass biotype (Echinochloa crus-galli) to herbicides quinclorac (synthetic auxin), penoxsulam (ALS inhibitor) and cyhalofop-butyl (ACCase inhibitor). Two experiments were carried out in a greenhouse located in Itajaí, State of Santa Catarina, Brazil. One experiment evaluating the biotype ECH 18 (known as susceptible) and one with the ECH 141 biotype (suspected to be multiple resistant). The experimental design used was completely randomized, in a 4 x 7 factorial arrangement with four replications. The first factor was the herbicide: cyhalofop-butyl (Clincher(r)), penoxsulam (Ricer(r)), quinclorac (Facet(r)) and propanil (Grassaid(r)) and the second factor consisting of seven rates of each herbicide (0.00; 0.25; 0.50; 1; 2; 4 and 8 times the label rate). The evaluations of percentage of control, plant density per pot and dry mass of shoots were performed 35 days after treatments. The rates to control 50% and 80% and the dose to provide 50% and 80% of the weed biomass accumulation and the resistance factor were estimated based on data analysis. The initial hypothesis was confirmed; the biotype ECH 141 presented multiple resistance (synthetic auxin, ALS and ACCase inhibitor). However, the herbicide propanil controlled biotype ECH 141 adequate.

Environmental factors affect the performance of fungicides in soybean (Glycine max (L.) Merr.). They also influence the residual activity of the products applied to the leaves. The objective of this study was to assess the control effectiveness of the interaction between fungicide application and rainfall simulation on Asian Soybean Rust (ASR). Two experiments were conducted, one in the greenhouse, in a completely randomized design, and the other in the field, in a randomized block design. Both the experiments had the same factorial arrangement of 6x5, with four replications. Factor A: Five fungicide applications time at 0400 h, 0900 h, 1400 h, 1800 h, 2300 h and, a control with no application; Factor B: four intervals of time between the application of fungicide and rainfall simulation at 0, 30, 60 and 120 min for the experiment in the greenhouse and at 2, 30, 60, 120 min for the experiment in the field. A control was included for both the experiments with no rainfall. The number of days to the appearance of the first pustules was determined, along with severity of ASR, relative chlorophyll index and productivity. It was found that the ASR control effectiveness of fungicide applications in soybean plants in sunlight was less efficient with rainfall simulation. The rainfall simulation had greater negative effect on disease control effectiveness in applications conducted at night under dew conditions. The application conducted at 0900 h showed the greatest disease control effectiveness in both greenhouse and in the field conditions. The 1400 h application showed decreased fungicide control residual and ASR control effectiveness, possibly due to a combination of the low relative humidity and high temperature. Rainfall simulation carried out at 120 min after application still had the ability to affect the ASR control effectiveness.

ABSTRACT: Horseweed is an annual cycle weed naturally controlled by the herbicide glyphosate. However, the continued use of this product has selected tolerant and resistant populations. The objective of this study is to analyze the occurrence of horseweed biotypes with a low glyphosate susceptibility in the states of Rio Grande do Sul, Paraná and Mato Grosso do Sul. Seeds of horseweed plants (Conyzaspp.) that survived glyphosate applications were collected in RR soybean crops, totaling 137 samples from 37 municipalities. The seeds of the biotypes were sown, and the plants originated from them, when they reached the stage of four to six leaves, were subjected to a treatment with 1,440ga.e.ha-1 of glyphosate. According to the results, 108biotypes were not controlled and 29 were controlled by the application of glyphosate. Thus, 78% of horseweed biotypes evaluated are not controlled by the dose 1,440ga.e.ha-1 of glyphosate, and 22% are susceptible to the same dose. Evaluating the distribution per state, Paraná, Rio Grande do Sul and Mato Grosso do Sul presented 83%, 77% and 77%, respectively, of biotypes not controlled by glyphosate at the dose used. Thus, most of the collected horseweed biotypes present a low sensitivity to glyphosate, thus confirming the high horseweed distribution with a low susceptibility to glyphosate in Mato Grosso do Sul, Paraná and Rio Grande do Sul.

ABSTRACT: Over the years, cultivated areas of sorghum have expanded considerably in Brazil. Chemical weed control has become an obstacle due to the scarcity of herbicides registered for the crop. The aim of this study was to evaluate the efficiency of weed control and selectivity of herbicides applied in pre and post emergence in the crop. Two experiments were conducted. In one of them, the hybrid BRS 310 was used while DKB 550 was used in the other. The experiments were performed in the field in randomized block design, evaluating seven treatments with four replications. The used treatments were: 1. Hand weeding, 2. S-metolachlor (1,440 g a.i. ha-1), 3. S-metolachlor (1,440 g a.i. ha-1) + atrazine (2,000 g a.i. ha-1), 4. atrazine (2,000 g a.i. ha-1), 5. atrazine (3,000 g a.i. ha-1), 6. atrazine (2,000 g a.i. ha-1) + mineral oil (0.25%), and 7. atrazine (2,000 g a.i. ha-1) + mineral oil (0.5%). It was verified that post-emergence atrazine was efficient in the weed control and selective to the sorghum crop, not affecting productivity, except in mixture with mineral oil (0.5%). S-metolachlor cannot be recommended in pre-emergence for the tested cultivars because it is not selective, reducing plants and productivity.

ABSTRACT: The repetitive use of glyphosate in the control of weeds in eucalyptus plantations has selected tolerant species such as Commelina benghalensis. Therefore, the use of herbicides of other mechanisms of action, such as saflufenacil, in rotation or combination with glyphosate, is necessary to reduce damages caused by C. benghalensis, whose sensitivity to herbicides can be influenced by the shading caused by the eucalyptus crop. This study aimed to assess the efficiency of saflufenacil in the management of C. benghalensis at different shading levels. Three experiments were carried out regarding a certain shading level (cultivation environment with 0, 40, and 55% shade). The experimental design was a randomized block design with five herbicide doses (0, 24.5, 49, 73.5, and 98 g ha-1 of saflufenacil) and four replications. At 28 days after herbicide application, the percentage of control and shoot dry matter were assessed, as well as the biomass allocation to leaves, stems, and roots of C. benghalensis. Plants cultivated at 0% shade presented a higher dry matter accumulation and a better distribution of biomass in leaves, stem, and roots, contributing with the increased tolerance to saflufenacil and not being controlled with effectiveness under the assessed doses. As shading was increased, plants of C. benghalensis allocated most of their biomass to the shoot, especially leaves, reducing their reserve structures and increasing the contact area with the herbicide, making them more susceptible to saflufenacil.

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The aim of this paper was quantify the effect of the herbicides clethodim and paraquat associated with different adjuvants class on phytotoxicity of Digitaria insularis at flowering stage. The herbicides were applied at 0, 6.25, 12.5, 25, 50, 75 and 100% of recommended label isolated or associated with the adjuvants: nonylphenoxy polyethoxy ethanol at 0.05%; silicone polyether copolymer at 0.1%; lecithin-based adjuvant and acid propionic at 0.5% and mineral oil at 0.5%. The experimental design was completely randomized with five replications in factorial scheme (herbicides rates x adjuvants). The phytotoxicity effect was visually assessed for paraquat at 12 days after treatment (DAT) and at 21 DAT for clethodim. The treatments applied clethodim with the adjuvants nonylphenoxy polyethoxy ethanol, lecithin-based adjuvant and acid propionic and mineral oil significantly increased the phytotoxicity of D. insularis plants. For the paraquat the increase phytotoxicity of D. insularis plants was provided by the treatment with the lecithin-based and acid propionic adjuvant. [ABSTRACT FROM AUTHOR]

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This study aimed to evaluate the control and susceptibility of signalgrass and ruzigrass in initial growth under different rates of glyphosate and fluazifop-p-butil. The treatments were distributed in a 2 × 6 factorial design, with five repetitions, being two grasses: Brachiaria decumbens cv. Basilisk (signalgrass) and B. ruziziensis (ruzigrass) with six doses of herbicides: 0.00; 0.25; 0.50; 1.00; 1.5 and 2.00 times the commercial dose recommended by manufacturers. At 7, 15, 21, and 30 days after herbicide application (DAA) were evaluated the intoxication in signalgrass and ruzigrass, visually. The glyphosate toxicity was of 100% in both plants, signalgrass and ruzigrass, even at the lowest dose (90 g ha-1), so it can control effectively these species in early growth stage. It was observed that the plants exposed to fluazifop-p-butil showed regrowth only in the doses to 100 g ha-1 and 50 g ha-1 for signalgrass and ruzigrass, respectively. These results confirm the effectiveness of this herbicide molecule in the control of these two species from doses of 200 g ha-1 and 100 g ha-1 for signal grass and ruzigrass, respectively. [ABSTRACT FROM AUTHOR]

The purpose of this work was to evaluate the selectivity of different herbicides in two seasons of application in the mung bean crop. The study was conducted at the State University of Goiás, Câmpus Ipameri. The treatments were arranged in a completely randomized design with six treatments (with weeding, without weeding, Fomesafen - 250 g i.a ha-1, Bentazon - 600 g i.a ha-1, Imazamox - 42 g i.a ha-1 and Paraquat dichloride - 400 g i.a ha-1), two herbicide application times (15 and 30 days after emergence), with four replicates, evaluated at 7, 15, 21 and 28 days after application. The evaluated characteristics were height, number of tripholes, diameter of plants and dry weight of shoots. The application of the paraquat dichloride caused death of the mung bean plants when applied in plants of 15 and 30 days of emergence. Bentazon, Imazamox and Fomesafen reduced initial growth when applied to 15 DAE, with subsequent recovery of the culture. Mung beans are tolerant to herbicides based on Bentazon, Imazamox and Fomesafen when applied at 15 and 30 days after emergence. Paraquat dichloride is not recommended for post-emergence use in the culture. [ABSTRACT FROM AUTHOR]