Associação dos herbicidas diclosulam e glyphosate na dessecação visando o controle residual de plantas daninhas na cultura da soja

The association of glyphosate and diclosulam in burndown can reduce the presence of weeds for a longer period, thus promoting the development and productivity of soybean plants. The objective was verify if the efficiency of the herbicide diclosulam associated with glyphosate, in burndown for direct seeding, in the seed bank of weeds in soybean grown in the plant system and apply. The straw present was Urochloa ruziziensis at 4.4 t ha-1 of dry mass, uniformly distributed over the experimental area. The experimental design was randomized blocks design with three treatments and four replications. The treatments consisted in the application of glyphosate at 1.2 kg ha-1 acid equivalent (a.e.) + diclosulam 25.2 g ha-1 active ingredient (a.i.) in pre-sowing without the complementary application, glyphosate at 1.2 kg ha-1 + diclosulam 25,2 ha-1 in pre-sowing of the culture + 1,2 kg ha-1 of glyphosate in complementation and glyphosate at 1.2 kg ha-1 in pre-sowing + glyphosate at 1.2 kg ha-1 in complementation. It were evaluated the initial reinfestation and relative density of weeds at 31 days after burndown, reinfestation of weeds at harvest time, difficulty of mechanized harvesting, number of pods per plant, 1000 grain weight and productivity. The association of the herbicides glyphosate and diclosulam assists in the initial management of weeds in soybean, without, however, dispense the complementary application of glyphosate.A associação dos herbicidas glyphosate e diclosulam na dessecação pode diminuir a presença de plantas daninhas por maior período, favorecendo assim o desenvolvimento e a produtividade das plantas de soja. Objetivou-se verificar a eficiência do herbicida diclosulam associado ao glyphosate, na dessecação para plantio direto da cultura de soja RR, cultivada no sistema plante e aplique. A cobertura vegetal presente foi Urochloa ruziziensis com 4,4 t ha-1, distribuída uniformemente sobre a área experimental. O delineamento experimental utilizado foi o de blocos ao acaso com três tratamentos e 4 repetições. Os tratamentos constituíram-se na aplicação de glyphosate a 1,2 kg ha-1 de equivalente ácido (e.a.) + diclosulam a 25,2 g ha-1 de ingrediente ativo (i.a.) em pré-semeadura da cultura sem a aplicação complementar, glyphosate a 1,2 kg ha-1 de e.a. + diclosulam a 25,2 g ha-1 de i.a. em pré-semeadura da cultura + glyphosate a 1,2 kg ha-1e.a. em complementação e glyphosate a 1,2 kg ha-1 de e.a. em pré-semeadura + glyphosate a 1,2 kg ha-1 de e.a. em complementação. Foram avaliados os seguintes parâmetros: reinfestação inicial e densidade relativa de plantas daninhas aos 31 dias após a dessecação, reinfestação de plantas daninhas no período da colheita, dificuldade de colheita mecanizada, número de vagens por planta, peso de 1000 grãos e produtividade de grãos. A associação do herbicida diclosulam ao glyphosate auxilia no manejo inicial da comunidade infestante no cultivo da soja, sem, no entanto, dispensar a aplicação complementar do herbicida glyphosate

Efficiency of chemical insecticides and association with Isaria javanica fungus on whitefly nymphs and adults

Submitted by Luciana Ferreira ([email protected]) on 2017-03-24T12:07:34Z No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2017-03-24T12:08:10Z (GMT) No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2017-03-24T12:08:10Z (GMT). No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-21Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPqThe main damage of whitefly Bemisia tabaci biotype B on beans is virus transmission such as Bean golden mosaic virus (BGMV) and Cowpea mild mottle virus (CpMMV). Different insecticides mechanisms of action, use of selective molecules and alternative methods of control are important techniques for management of this insect. Therefore, this study was conducted to test the efficiency of chemical insecticides on mortality of whiteflies adults and CpMMV transmission on BGMV-resistant transgenic common bean; and to verify the combination of chemical insecticides in sublethal doses with the entomopathogeni fungus Isaria javanica on control of B. tabaci nymhps in commom bean. In first part of the study two experiments were conducted with seed treatments, one with foliar application and another with the combination with seed treatment and foliar application. Experiments were conducted in screenhouse. In first experiment with seeds treatment thiametoxam FS at 300, 500, 700 mL and imidacloprid+thiodicarb FS at 500, 600 e 800 mL were tested. In second experiment were used higher doses of thiametoxam FS (500, 700 e 900 mL) and imidacloprid+thiodicarb FS (600, 800 e 1.000 mL). In foliar application were evaluated the insecticides thiamethoxam+cyantraniliprole WG and flupyradifurone SL at 500 e 750 mL ha-1, thiamethoxam + lambda-cyhalothrin SC and thiamethoxam WG both at 300 mL ha-1. In combination of seed treatment and foliar application the treatments were plants treated only with seed treatment or with ST following 1, 2, 3 or 4 foliar applications with different insecticides at five-days intervals. On second stage, at laboratory the compatibility of spiromesifen and buprofezin with I. javanica was observed. Different insecticides concentrations (12.5; 25; 50 and 100 ppm) were added to conidia suspension. Germination of conidia, mycelial growth and conidial production were evaluated. On screenhouse were determined: 1) the sublethal (CL25) doses of insecticides spiromesifen and buprofezin to 2nd ínstar whitefly nymphs; 2) the bio-efficacy of different isolates of I. javanica to 2nd ínstar whitefly nymphs and 3) the effect of the combination between spiromesifen and buprofezin with I. javanica on control of 2nd ínstar whitefly nymphs. Nymphal mortality and sporulation on cadavers (2 and 3) were evaluated. As result was observed that thiametoxam + ciantraniliprole WG and flupiradifurone SL applied in foliar application resulted in higher mortality of whitefly adults. ST added 3 or 4 foliar application proportioned the highest mortality and reduction on CpMMV transmission. Insecticides are efficient on B. tabaci control; however, it does not avoid the virus transmission. The combinations of ST added 3 or 4 foliar application reduce the CpMMV on 50%. All I. javanica isolates caused nymphal mortalities. Spiromesifen and buprofezin were compatible with I. javanica. Additive and synergistic effects were observed. A management program of whitefly is important to reduction of CpMMV incidence on BGMV-resistant transgenic common bean. Besides, the combination of selective chemical insecticides and I. javanica on B. tabaci might increase the success of control.O principal dano da mosca-branca Bemisia tabaci biótipo B na cultura do feijoeiro é a transmissão de vírus, como o Bean golden mosaic virus (BGMV) e o Cowpea mild mottle virus (CpMMV). A rotação de mecanismos de ação dos inseticidas, o uso de moléculas seletivas e de métodos de controle alternativos são técnicas importantes para o manejo deste inseto. Os objetivos do estudo foram testar a eficiência de inseticidas químicos na mortalidade de adultos de mosca-branca e na transmissão de CpMMV no feijoeiro geneticamente modificado resistente ao mosaico dourado (RMD) e a associação de inseticidas químicos em doses subletais com o fungo Isaria javanica no controle de ninfas de B. tabaci em feijoeiro-comum. Na primeira etapa do estudo em casa telada, dois experimentos foram realizados com tratamento de sementes, um com aplicação foliar e outro com a combinação de tratamento de sementes e aplicação foliar. No primeiro experimento com tratamento de sementes (TS) os inseticidas thiametoxam FS nas doses 300, 500, 700 mL e imidacloprid+thiodicarb FS nas doses 500, 600 e 800 mL foram testados. Já no segundo TS foram utilizados doses maiores de thiametoxam FS (500, 700 e 900 mL) e de imidacloprid+thiodicarb FS (600, 800 e 1000 mL). Em pulverização foram avaliados os inseticidas thiamethoxam+cyantraniliprole WG (500 e 750 mL ha-1), flupyradifurone SL (500 e 750 mL ha-1), thiamethoxam+lambda-cyhalothrin SC (300 mL ha-1) e thiamethoxam WG (300 mL ha-1). Na combinação de tratamento de sementes e aplicação foliar, as plantas foram tratadas apenas com TS ou com TS seguido de 1, 2, 3 ou 4 pulverizações com diferentes inseticidas a cada 5 dias. Na segunda etapa para verificar a compatibilidade dos inseticidas spiromesifen e buprofezin com o I. javanica, concentrações destes inseticidas (12,5; 25; 50 e 100 ppm) foram adicionadas à suspensão de conídios. Foram avaliados a germinação de conídios, crescimento micelial e produção de conídios. Em casa telada foram determinados: 1) a dose subletal (CL25) dos inseticidas spiromesifen e buprofezin a ninfas de mosca-branca; 2) a bio-eficácia de isolados de I. javanica à ninfas de mosca-branca; e 3) o efeito da combinação de spiromesifen e buprofezin e I. javanica no controle de ninfas de mosca-branca. A mortalidade das ninfas e a esporulação nos cadáveres (2 e 3) foram avaliadas. No primeiro estudo o tiametoxam+ciantraniliprole WG e flupiradifurona SL em pulverização foliar resultaram em maiores mortalidades de mosca-branca. Os inseticidas são eficientes no controle de mosca-branca. Apenas a combinação de TS mais 3 ou 4 pulverizações foliares reduzem a incidência de CpMMV. No segundo estudo, todos os isolados causaram morte de ninfas. Os inseticidas foram compatíveis com I. javanica. Efeitos aditivo e sinérgico foram observados entre I. javanica e spiromesifen e buprofezin no controle de ninfas de mosca-branca. Um programa de manejo de B. tabaci é importante para a redução de CpMMV no feijoeiro RMD. Além disso, a combinação de inseticidas sintéticos seletivos e o fungo I. javanica pode aumentar o sucesso do controle de ninfas de mosca-branca

Yield and technological quality of sugarcane cultivars under infestation of Diatraea saccharalis (Fabr., 1794)

ABSTRACT: The sugarcane borer, Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae), is one of the main pests of sugarcane. This pest can reduce the quality and yield of the crop. Information on the quality and yield of cultivars in relation to the attack of sugarcane borer are necessary, since they guide the choice of the best materials for use in joint with other management tactics. Two field experiments were conducted in 2011 and 2012 to compare the quality and yield of 16 commercial sugarcane cultivars (IACSP93-3046, IACSP94-2094, IACSP94-2101, IAC91-1099, IACSP95-5000, IAC87-3396, RB92579, RB867515, RB966928, CTC2, CTC4, CTC9, CTC11, CTC15, CTC18 and SP86-0042) relative to the natural infestation of D. saccharalis. The experimental design was a randomized complete block with four replications. There was no difference between treatments for infestation index, with averages of 1.2 to 8.7% of bored internodes. Higher percentages of internodes with red rot were observed for CTC9, CTC2 and RB966928. The cultivars CTC4 and RB92579 infested with D. saccharalis resulted in lower technological quality, due the reduction in the contents of brix, apparent sucrose content (POL) and purity; and increase of the reducing sugars and, consequently, lower theoretically recoverable sugar (TRS). On the other hand, the lowest yields (t of cane ha-1) were observed for CTC18, IACSP94-2094, IACSP94-2101 and RB966928. Therefore, according to the hierarchical cluster analysis (UPGMA), the cultivars RB867515, CTC11, IAC91-1099, CTC15, SP86-0042, CTC2 and IACSP94-3046 were resistant to D. saccharalis