Effects of mixtures of arrestants, dislodgers, and phagostimulants with synthetic insecticides on green-belly stink bug: walking behavior assessments, physicochemical interactions, and laboratory and field trials.

The green-belly stink bug (Diceraeus melacanthus Dallas (Hemiptera: Pentatomidae)) is a key pest of corn-soybean crop systems and the management of this pest is difficult due to behavioral characteristics. However, products that alter its behavior, such as arrestants, dislodgers, and phagostimulants, have been used in an attempt to improve the effectiveness of chemical control. In this study, the effect of these products on the walking behavior of nymphs and adults of D. melacanthus was initially evaluated through computational behavioral tracking (Ethovision system). Adults of D. melacanthus exposed to the dislodgers Creolin Pearson and Quimifol S450 (sulfur) significantly increased the distance covered and the walking speed. On the other hand, the only treatment that significantly affected the walking behavior of nymphs was the treatment with soy milk (phagostimulant). The physical-chemical analyses indicated considerable changes in the pH and electrical conductivity of mixtures of such products with insecticides from different chemical groups, as well as lack of homogeneity (physical incompatibility). Nevertheless, none of the products tested improved the control efficacy of an insecticide based on imidacloprid + beta-cyfluthrin, either in laboratory tests (contact bioassay) or in tests conducted in corn crops during 2 crop harvests. Thus, the association of these products in a tank mixture does not increase the control levels of D. melacanthus in post-emergence of maize and may have an antagonistic effect in some associations.

Influence of adjuvants added to teflubenzuron spray on resistant and susceptible strains of the soybean looper Chrysodeixis includens (Lepidoptera: Noctuidae) / Influência da adição de adjuvantes à calda de pulverização de teflubenzuron em linhagens resistentes e suscetíveis da lagarta falsa-medideira Chrysodeixis includens em soja (Lepidoptera: Noctuidae)

ABSTRACT: The soybean looper (SBL), Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae), is a soybean and cotton pest in South America countries. Field-evolved resistance of SBL to inhibitors of chitin biosynthesis has been reported in Brazil; however, this mode of action is still widely used against SBL. On this basis, we conducted laboratory bioassays to investigate if adjuvants (Nimbus®, TA 35®, Break-Thru® S 240, and Rizospray Extremo®) added to the teflubenzuron spray increase the mortality of SBL strains (resistant, heterozygous, and susceptible to chitin biosynthesis inhibitors). Using chromatography analysis, we also evaluated the amount of teflubenzuron on soybean leaves when applied alone or in combination with adjuvants. In laboratory bioassays, the biological activity of teflubenzuron increased against the susceptible SBL strain when adjuvants were added. In contrast, no relevant effects of adjuvants added to the teflubenzuron spray against heterozygous and resistant SBL larvae were detected. In leaf bioassays, even leaves from the upper third part of the plants containing a significantly higher amount of teflubenzuron (3.4 mg/kg vs 1.7 and 0.6 mg/kg); the mortality of SBL strains was similar when teflubenzuron was applied alone or in mixture with adjuvants. Our findings indicated that adjuvants added to teflubenzuron spray do not provide a substantial increase in the mortality of SBL strains resistant to chitin biosynthesis inhibitors. Therefore, it is necessary to reduce the use of this mode-of-action insecticide against SBL and to give preference to other insecticides or control tactic.

RESUMO: A lagarta falsa-medideira, Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae), é uma praga da soja e do algodão nos países da América do Sul. A resistência de C. includens a inibidores da biossíntese de quitina tem sido relatada no Brasil. Entretanto, esse modo de ação ainda é amplamente utilizado para controle de C. includens. Com base nisso, conduzimos bioensaios em laboratório para investigar se adjuvantes (Nimbus®, TA 35®, Break-Thru® S 240 e Rizospray Extremo®) adicionados à calda inseticida de teflubenzuron aumentam a mortalidade de linhagens de C. includens (resistentes, heterozigotos e suscetíveis a inibidores da biossíntese de quitina). Usando análise cromatográfica, também avaliamos a quantidade de teflubenzuron em folhas de soja quando aplicado isolado ou em combinação com adjuvantes. Em bioensaios de laboratório, a atividade biológica do teflubenzuron aumentou para a linhagem suscetível quando os adjuvantes foram adicionados à calda inseticida. Em contraste, nenhum efeito relevante de adjuvantes adicionados ao teflubenzuron foi detectado para os heterozigotos e resistentes. Em bioensaios de folhas, mesmo naquelas do terço superior das plantas, as quais apresentaram uma maior deposição de teflubenzuron (3,4 mg/kg vs 1,7 e 0,6 mg/kg); a mortalidade das linhagens de C. includens foi semelhante quando o teflubenzuron foi aplicado isolado ou com adjuvantes. Nossos resultados indicam que os adjuvantes adicionados ao teflubenzuron não fornecem um aumento substancial na mortalidade de linhagens de C. includens resistentes aos inibidores da biossíntese de quitina. Portanto, é necessário reduzir o uso desse modo de ação para o manejo de C. includens e dar preferência a outros inseticidas ou tática de controle.

Influence of adjuvants added to teflubenzuron spray on resistant and susceptible strains of the soybean looper Chrysodeixis includens (Lepidoptera: Noctuidae) / Influência da adição de adjuvantes à calda de pulverização de teflubenzuron em linhagens resistentes e suscetíveis da lagarta falsa-medideira Chrysodeixis includens em soja (Lepidoptera: Noctuidae)

The soybean looper (SBL), Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae), is a soybean and cotton pest in South America countries. Field-evolved resistance of SBL to inhibitors of chitin biosynthesis has been reported in Brazil; however, this mode of action is still widely used against SBL. On this basis, we conducted laboratory bioassays to investigate if adjuvants (Nimbus®, TA 35®, Break-Thru® S 240, and Rizospray Extremo®) added to the teflubenzuron spray increase the mortality of SBL strains (resistant, heterozygous, and susceptible to chitin biosynthesis inhibitors). Using chromatography analysis, we also evaluated the amount of teflubenzuron on soybean leaves when applied alone or in combination with adjuvants. In laboratory bioassays, the biological activity of teflubenzuron increased against the susceptible SBL strain when adjuvants were added. In contrast, no relevant effects of adjuvants added to the teflubenzuron spray against heterozygous and resistant SBL larvae were detected. In leaf bioassays, even leaves from the upper third part of the plants containing a significantly higher amount of teflubenzuron (3.4 mg/kg vs 1.7 and 0.6 mg/kg); the mortality of SBL strains was similar when teflubenzuron was applied alone or in mixture with adjuvants. Our findings indicated that adjuvants added to teflubenzuron spray do not provide a substantial increase in the mortality of SBL strains resistant to chitin biosynthesis inhibitors. Therefore, it is necessary to reduce the use of this mode-ofaction insecticide against SBL and to give preference to other insecticides or control tactic.

A lagarta falsa-medideira, Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae), é uma praga da soja e do algodão nos países da América do Sul. A resistência de C. includens a inibidores da biossíntese de quitina tem sido relatada no Brasil. Entretanto, esse modo de ação ainda é amplamente utilizado para controle de C. includens. Com base nisso, conduzimos bioensaios em laboratório para investigar se adjuvantes (Nimbus®, TA 35®, Break-Thru® S 240 e Rizospray Extremo®) adicionados à calda inseticida de teflubenzuron aumentam a mortalidade de linhagens de C. includens (resistentes, heterozigotos e suscetíveis a inibidores da biossíntese de quitina). Usando análise cromatográfica, também avaliamos a quantidade de teflubenzuron em folhas de soja quando aplicado isolado ou em combinação com adjuvantes. Em bioensaios de laboratório, a atividade biológica do teflubenzuron aumentou para a linhagem suscetível quando os adjuvantes foram adicionados à calda inseticida. Em contraste, nenhum efeito relevante de adjuvantes adicionados ao teflubenzuron foi detectado para os heterozigotos e resistentes. Em bioensaios de folhas, mesmo naquelas do terço superior das plantas, as quais apresentaram uma maior deposição de teflubenzuron (3,4 mg/kg vs 1,7 e 0,6 mg/kg); a mortalidade das linhagens de C. includens foi semelhante quando o teflubenzuron foi aplicado isolado ou com adjuvantes. Nossos resultados indicam que os adjuvantes adicionados ao teflubenzuron não fornecem um aumento substancial na mortalidade de linhagens de C. includens resistentes aos inibidores da biossíntese de quitina. Portanto, é necessário reduzir o uso desse modo de ação para o manejo de C. includens e dar preferência a outros inseticidas ou tática de controle.

Interaction between pesticides applied alone or in mixtures in corn.

The objective of this work was to evaluate the selectivity of herbicides applied alone or in tank mix, and also of combinations of different classes of pesticides (fungicides, herbicides and insecticides) on corn. An experiment was installed in the 2017/18 crop to assess herbicide selectivity, and repeated in 2018/19. The second experiment aimed to assess the selectivity of mixtures of different classes of pesticides, and was installed only in 2017/18. The experimental design adopted in the tests was randomized blocks, with four replicates. In each trial, a total of 16 treatments were evaluated, plus a control. At 7, 14 and 21 days after the application of treatments the phytotoxicity to corn was evaluated and the yield components and grain yield were determined. Herbicides caused low levels of injury to the corn plants, with small variations in yield components, and affected crop yield differently. The mixtures of pesticides promoted low phytotoxicity, affected yield components inconsistently and caused changes in corn yield. Although these herbicides and other pesticides are registered for use in corn crops, application alone or in tank mix of certain molecules can cause losses in grain yield.

Adjuvants plus phytosanitary products and the effects on the physical-chemical properties of the spray liquids / Adjuvantes mais produtos fitossanitários e os efeitos nas propriedades físico-químicas da calda

The frequent tank mixing of phytosanitary products, adjuvants, and foliar fertilizers highlights the lack of information which sustains decisions about what products can be mixed for spray application. Thus, the aim of this study was to evaluate the physical and chemical characteristics of fungicides, herbicides, and insecticides in combination with some adjuvants on the Brazilian market. The experimental design was completely randomized and spray mixes of the phytosanitary products: fungicide (azoxystrobin+benzovindiflupir), herbicide (diamônio salt of N-(phosponomethyl)) or insecticide (fenpropathrin) were evaluated in combination with adjuvants (mineral oil base, foliar fertilizer or lecithin + propionic acid), and in two application rates (95 and 52 L ha-1); all with four replications. Surface tension, electrical conductivity, pH, dynamic viscosity and density of spray mixes were evaluated. The adjuvants presented characteristics capable of significantly altering the physicochemical properties of the phytosanitary spray mixes, and thus, alter the biological effectiveness and efficiency of the spray applications. However, its effects are also dependent on the phytosanitary product added to the spray mix, which makes general recommendations a difficult task. The greatest pH reduction, as well as the greatest increase in electrical conductivity, were caused by the adjuvant lecithin + propionic acid. All phytosanitary products and adjuvants studied, associated or not, resulted in a reduction in the surface tension of the spray mix in relation to water. The magnitude of change of density and dynamic viscosity promoted by adjuvants was lower than the other characteristics evaluated.

A realização frequente de misturas em tanque de produtos fitossanitários, adjuvantes e fertilizantes foliares traz à tona a carência de informações que amparem as decisões sobre quais produtos podem ser misturados. O objetivo deste trabalho foi avaliar características físicas e químicas de caldas fungicidas, herbicidas e inseticidas em combinação com alguns adjuvantes do mercado. O delineamento experimental utilizado foi inteiramente casualizado, sendo avaliadas diferentes caldas com o fungicida azoxistrobina+benzovindiflupir, herbicida sal de diamônio de N-(phosponomethyl) e inseticida fenpropatrina, em combinação com adjuvantes a base de óleo mineral, fertilizante foliar e lecitina de soja+ácido propiônico, considerando duas taxas de aplicação (95 e 52 L ha-1), todos os tratamentos com quatro repetições. Foram avaliadas as seguintes características: tensão superficial, condutividade elétrica, pH, viscosidade dinâmica e densidade. Os adjuvantes apresentaram características capazes de alterar significativamente as propriedades físico-químicas das caldas fitossanitárias, podendo, assim, alterar a eficácia biológica e a eficiência das aplicações. Contudo, seu efeito também é dependente do produto fitossanitário adicionado à calda, o que dificulta generalizações. A maior redução do pH, bem como o maior aumento na condutividade elétrica da calda, foram ocasionados pelo adjuvante lecitina+ácido propiônico. Todos os produtos fitossanitários e adjuvantes, de forma associada ou não, provocaram redução na tensão superficial da calda em relação à água. A magnitude das alterações de densidade e viscosidade dinâmica promovida pelos adjuvantes foi inferior às demais características avaliadas.

Respiration induced by substrate and bacteria diversity after application of diuron, hexazinone, and sulfometuron-methyl alone and in mixture.

After application, herbicides often reach the soil and affect non-target soil microorganisms, decreasing their population, diversity or affecting metabolic activity. Therefore, laboratory studies were performed to evaluate the effects of diuron, hexazinone and sulfometuron-methyl alone and mixed upon carbon transformation by soil microorganisms in clayey and sandy soils and the effect on bacterial diversity and structure. Control treatment without herbicide application was also performed. Sub-samples from the control and herbicide treatments (10 g - in triplicate) were collected before herbicide application and 7, 14, 28 and 42 days after treatment (DAT), then 1 mL of 14C-glucose solution was applied. The released 14CO2 was trapped in 2 M NaOH solution and the radioactivity was analyzed by liquid scintillation counting (LSC), 12 h after glucose application. The effect of herbicides on bacterial diversity was evaluated by T-RFLP. The experiment was conducted in a complete randomized design. Hexazinone did not affect 14CO2 evolution. Diuron showed a greater 14CO2 evolution in sandy and clayey soil, while sulfometuron-methyl led to an increase in sandy soil, at 42 DAT. A greater evolution of carbon was observed in the treatment with herbicide mixture in sandy soil, compared with the same treatment in clayey soil or control. However, the herbicide mixture application did not affect the soil biological activity measured by the respiration rate induced by substrate. On the other hand, the herbicide mixtures affected the bacterial diversity in both soils, being the strongest effect to diuron and sulfometuron-methyl in clayey soil and hexazinone in sandy soil.

Interaction of spirodiclofen with insecticides for the control of Brevipalpus yothersi in citrus.

BACKGROUND: The mite Brevipalpus yothersi (Acari: Tenuipalpidae) is of great importance in citriculture because it is a vector of the disease citrus leprosis. The frequency of application of a combination of pesticides has increased because of an increase in the occurrence of economically important pests of citrus. However, the combined effect of acaricide and other insecticides targeting B. yothersi is unknown. The objective of this study was to evaluate the effect of a combination of spirodiclofen and other insecticides on the control of B. yothersi. RESULTS: Analysis using spirodiclofen alone resulted in 97.22% efficiency in the control of B. yothersi on day 7 after application. A combination of spirodiclofen with either phosmet or imidacloprid resulted in 55% and 59% efficiency, respectively. A reduction in the efficiency of mite control by up to 42% was observed when the mites were exposed to a combination of acaricide with other insecticides. CONCLUSIONS: Application of a combination of spirodiclofen with phosmet or imidacloprid compromises the efficiency of acaricide in the control of B. yothersi. © 2018 Society of Chemical Industry.

Leaching of Diuron, Hexazinone, and Sulfometuron-methyl Applied Alone and in Mixture in Soils with Contrasting Textures.

When herbicides are applied in mixture, interactions among them could potentially promote changes in herbicide behavior in the soil. Thus, application mode (isolated or in mixture) and soil texture (sandy or clayey) were investigated in the total leaching of the commercial mixture diuron + hexazinone + sulfometuron-methyl, and of each isolated compound. Experiments in soil columns also evaluated the movement of each herbicide and mixtures across soil layers. In the sandy soil, the greatest total leaching was observed with hexazinone compared to diuron and sulfometuron. Most of the applied diuron remained at the top layer of the soil, indicating that this herbicide has low soil mobility. Overall, our results show that hexazinone has greater leaching potential and mobility along the soil profile compared to diuron and sulfometuron. Our data can be used in assessing the fate of diuron, hexazinone, and sulfometuron alone or in mixture on natural ecosystems, under different soil types and application modes.

Synergism of mixtures of glyphosate and PROTOX inhibitor herbicides for morning-glory control / Sinergismo de misturas de glyphosate e herbicidas inibidores da PROTOX no controle de corda-de-viola

Weeds can cause significant agricultural yield losses, and the morning-glory species (Ipomoea spp.) has stood out in several crops. To control morning-glories we can use herbicides inhibiting the protoporphyrinogen IX oxidase enzyme in addition to glyphosate, a herbicide that this weed is intolerant to. The objective was to test the efficacy of application of isolates and mixtures of glyphosate (Roundup Original®) with carfentrazone-ethyl (Aurora®) and saflufenacil (Heat®) to control I. hederifolia in two weed growth stages. Treatments consisted of: isolated application of (i) carfentrazone-ethyl (50 and 75 mL l.h. ha-1), (ii) saflufenacil (35 and 50 g l.h. ha-1, and (iii) glyphosate (2 and 4 L l.h. ha-1; and mixtures of (iv) carfentrazone-ethyl+glyphosate and (v) saflufenacil+glyphosate (both in the lowest dose). Applications were performed on plants with 6-8 and 15-20 leaves, maintaining herbicide-free checks for both plant growth stages. Mixture of carfentrazone-ethyl and saflufenacil with glyphosate increases the efficacy of control of I. hederifolia, compared to herbicide isolate applications. Mixture of 2 L ha-1 + 50 mL ha-1 of glyphosate+carfentrazone-ethyl provides more efficient and faster control of I. hederifolia, mainly when the plants have 6-8 leaves.(AU)

As plantas daninhas podem causar perdas significativas de produtividade na agricultura, dentre as quais se destacam as cordas-de-viola (Ipomoea spp.) em diversos cultivos. Para seu controle podem ser utilizados herbicidas inibidores da enzima protoporfirinogênio IX oxidase em complementação ao glyphosate, ao qual essa planta daninha é tolerante. O objetivo foi testar a eficácia de aplicações isoladas e em mistura de glyphosate (Roundup Original®) com carfentrazone-ethyl (Aurora®) e saflufenacil (Heat®) no controle de I. hederifolia em dois estádios de desenvolvimento da planta daninha. Os tratamentos foram: aplicação isolada de (i) carfentrazone-ethyl (50 e 75 mL p.c. ha-1), (ii) saflufenacil (35 e 50 g p.c. ha-1), e (iii) glyphosate (2 e 4 L p.c. ha-1); e em mistura de (iv) carfentrazone-ethyl+glyphosate e (v) saflufenacil+glyphosate (ambos na menor dose). As aplicações ocorreram em plantas de 6-8 folhas e 15-20 folhas, mantendo-se testemunhas sem aplicação para esses dois estádios. A mistura dos herbicidas carfentrazone-ethyl e saflufenacil com glyphosate proporciona aumento na eficácia de controle de I. hederifolia, em relação à aplicação dos herbicidas isolados. A mistura de glyphosate+carfentrazone-ethyl na dose de 2 L ha-1 + 50 mL ha-1 proporciona controle mais eficaz e mais rápido de I. hederifolia, principalmente quando as plantas estão no estádio de 6-8 folhas.(AU)

Synergism of mixtures of glyphosate and PROTOX inhibitor herbicides for morning-glory control / Sinergismo de misturas de glyphosate e herbicidas inibidores da PROTOX no controle de corda-de-viola

Weeds can cause significant agricultural yield losses, and the morning-glory species (Ipomoea spp.) has stood out in several crops. To control morning-glories we can use herbicides inhibiting the protoporphyrinogen IX oxidase enzyme in addition to glyphosate, a herbicide that this weed is intolerant to. The objective was to test the efficacy of application of isolates and mixtures of glyphosate (Roundup Original®) with carfentrazone-ethyl (Aurora®) and saflufenacil (Heat®) to control I. hederifolia in two weed growth stages. Treatments consisted of: isolated application of (i) carfentrazone-ethyl (50 and 75 mL l.h. ha-1), (ii) saflufenacil (35 and 50 g l.h. ha-1, and (iii) glyphosate (2 and 4 L l.h. ha-1; and mixtures of (iv) carfentrazone-ethyl+glyphosate and (v) saflufenacil+glyphosate (both in the lowest dose). Applications were performed on plants with 6-8 and 15-20 leaves, maintaining herbicide-free checks for both plant growth stages. Mixture of carfentrazone-ethyl and saflufenacil with glyphosate increases the efficacy of control of I. hederifolia, compared to herbicide isolate applications. Mixture of 2 L ha-1 + 50 mL ha-1 of glyphosate+carfentrazone-ethyl provides more efficient and faster control of I. hederifolia, mainly when the plants have 6-8 leaves.

As plantas daninhas podem causar perdas significativas de produtividade na agricultura, dentre as quais se destacam as cordas-de-viola (Ipomoea spp.) em diversos cultivos. Para seu controle podem ser utilizados herbicidas inibidores da enzima protoporfirinogênio IX oxidase em complementação ao glyphosate, ao qual essa planta daninha é tolerante. O objetivo foi testar a eficácia de aplicações isoladas e em mistura de glyphosate (Roundup Original®) com carfentrazone-ethyl (Aurora®) e saflufenacil (Heat®) no controle de I. hederifolia em dois estádios de desenvolvimento da planta daninha. Os tratamentos foram: aplicação isolada de (i) carfentrazone-ethyl (50 e 75 mL p.c. ha-1), (ii) saflufenacil (35 e 50 g p.c. ha-1), e (iii) glyphosate (2 e 4 L p.c. ha-1); e em mistura de (iv) carfentrazone-ethyl+glyphosate e (v) saflufenacil+glyphosate (ambos na menor dose). As aplicações ocorreram em plantas de 6-8 folhas e 15-20 folhas, mantendo-se testemunhas sem aplicação para esses dois estádios. A mistura dos herbicidas carfentrazone-ethyl e saflufenacil com glyphosate proporciona aumento na eficácia de controle de I. hederifolia, em relação à aplicação dos herbicidas isolados. A mistura de glyphosate+carfentrazone-ethyl na dose de 2 L ha-1 + 50 mL ha-1 proporciona controle mais eficaz e mais rápido de I. hederifolia, principalmente quando as plantas estão no estádio de 6-8 folhas.

Selectivity of preemergence herbicide treatments for cotton crop / Seletividade de herbicidas aplicados em pre-emergencia na cultura do algodoeiro

The use of preemergence herbicides in cotton crop is one of the main tools in weed control. However, little is known about the effects of different herbicide tank mixtures on this crop. Therefore, this work was aimed at evaluating the selectivity of herbicides applied isolated or in mixtures to cotton at preemergence. Herbicide treatments included alachlor, s-metolachlor, diuron, prometryn, trifluralin, oxyfluorfen, alachlor+diuron, alachlor+prometryn, s-metolachlor+diuron, s-metolachlor+prometryn, oxyfluorfen+diuron, oxyfluorfen+prometryn, trifluralin+diuron, trifluralin+prometryn, trifluralin+oxyfluorfen. Herbicide treatments did not affect cotton stand. Oxyfluorfen, isolated or in mixture with diuron, prometryn, and trifluralin caused more significant crop injuries than all the other herbicide treatments. However, only oxyfluorfen+diuron, and trifluralin+oxyfluorfen decreased crop yield, and are regarded as presenting lower selectivity to cotton, cv. Delta-Opal.

O uso de herbicidas em pré-emergência da cultura do algodoeiro é uma das principais ferramentas no controle de plantas daninhas. Entretanto, pouco se conhece sobre os efeitos de misturas em tanque de diferentes produtos nessa cultura. Dessa forma, este trabalho teve por objetivo avaliar a seletividade de herbicidas aplicados em préemergência, isolados ou em misturas, na cultura do algodão. Os tratamentos testados foram compostos dos seguintes herbicidas e suas respectivas doses (g a.i. ha-1): alachlor (1440), S-metolachlor (768), diuron (1500), prometryn (1500), trifluralin (1800), and oxyfluorfen (192) aplicados isoladamente, e em mistura formando os seguintes tratamentos: alachlor+diuron (1440+1500), alachlor+prometryn (1440+1500), S-metolachlor+diuron (768+1500), Smetolachlor+prometryn (768+1500), oxyfluorfen+diuron (192+1500), oxyfluorfen+prometryn (192+1500), trifluralin+diuron (1800+1500), trifluralin+prometryn (1800+1500), e trifluralin+oxyfluorfen (1800+192). O experimento foi conduzido por meio de testemunhas duplas. Foram realizadas avaliações relacionadas à fitointoxicação visual, altura de planta, número de maçãs e produção de algodão em caroço. Os tratamentos herbicidas não influenciaram o estande da cultura do algodoeiro. O herbicida oxyfluorfen isolado ou em mistura com diuron, prometryn e trifluralin proporcionaram maior fitointoxicação à cultura em relação aos demais tratamentos. Entretanto, somente oxyfluorfen + diuron e trifluralin + oxyfluorfen apresentaram rendimento inferior à testemunha, sendo considerados, portanto, de baixa seletividade para o cultivar Delta-Opal.