RESUMO
Yellow sigatoka (Mycosphaerella musicola) is the main disease in banana areas in the Santa Catarina state. The objective of this research was to evaluate the effect of different methods of chemical and cultural control of sigatoka disease on Prata banana in subtropical climate. Six treatments were tested, evaluating three formulations (Tebuconazole 0,5 L ha-1 - Tiofanato metílico 0,6 L ha-1; Citric biomass 1,0 L ha-1; water) with or without leaf removal. The variables evaluated were under the curve of progress (AUDPC) and final gross sum (GSfinal) area. The experimental design was randomized blocks in factorial scheme with five repetitions. Treatments were compared with Duncan´s test (P 0,05). Significant differences were verified for products compared to control, but not for leaf removal. It was found that fungicides and citric biomass resulted in significant reductions in AUDPC and GS final when compared to control. Fungicides and citric biomass reduced area under disease progress curve by 65 and 63%, as well as final gross sum were 87 and 73%, respectively. Results showed small influence of leaf removal, but new studies should evaluate its influence with higher frequency of defoliation. Fungicides and citric biomass are efficient in controlling sigatoka.(AU)
A sigatoka amarela (Mycosphaerella musicola) ainda é a principal doença da cultura da bananeira em Santa Catarina. Este trabalho teve como objetivo avaliar a eficiência de fungicidas e da desfolha no controle da Sigatoka em banana Prata. Foram testados seis tratamentos, combinando-se três formulações (Tebuconazole 0,5 L ha-1 - tiofanato metílico 0,6 L ha-1; Biomassa cítrica 1,0 L ha-1; água) com ou sem desfolha. As variáveis avaliadas foram área abaixo da curva de progresso (AACPD) e soma bruta final (SBfinal) da doença. O delineamento experimental foi blocos ao acaso em esquema fatorial com cinco repetições, comparados entre si pelo teste de Duncan (P 0,05). Foram verificadas diferenças significativas para as formulações, mas não para desfolha, em comparação com testemunha. Para o fator formulação verificou-se que os fungicidas e a biomassa cítrica proporcionaram reduções significativas da área abaixo da curva de progresso da doença (AACPD) e soma bruta final (SBfinal) em comparação com testemunha. Os fungicidas e a biomassa cítrica reduziram a área abaixo da curva de progresso em 65 e 63%, assim como a soma bruta final caiu 83 e 73% em comparação com testemunha, respectivamente. Não se verificou influência da desfolha no controle da sigatoka, porém outros estudos com aplicações mais freqüentes devem ser realizados para quantificar melhor seu efeito. Concluiu-se que os fungicidas e a biomassa cítrica são eficientes no controle da sigatoka.(AU)
Assuntos
Biomassa , Desfolhantes Químicos/análise , Desfolhantes Químicos/síntese química , CitrusRESUMO
Yellow sigatoka (Mycosphaerella musicola) is the main disease in banana areas in the Santa Catarina state. The objective of this research was to evaluate the effect of different methods of chemical and cultural control of sigatoka disease on Prata banana in subtropical climate. Six treatments were tested, evaluating three formulations (Tebuconazole 0,5 L ha-1 - Tiofanato metílico 0,6 L ha-1; Citric biomass 1,0 L ha-1; water) with or without leaf removal. The variables evaluated were under the curve of progress (AUDPC) and final gross sum (GSfinal) area. The experimental design was randomized blocks in factorial scheme with five repetitions. Treatments were compared with Duncan´s test (P 0,05). Significant differences were verified for products compared to control, but not for leaf removal. It was found that fungicides and citric biomass resulted in significant reductions in AUDPC and GS final when compared to control. Fungicides and citric biomass reduced area under disease progress curve by 65 and 63%, as well as final gross sum were 87 and 73%, respectively. Results showed small influence of leaf removal, but new studies should evaluate its influence with higher frequency of defoliation. Fungicides and citric biomass are efficient in controlling sigatoka.
A sigatoka amarela (Mycosphaerella musicola) ainda é a principal doença da cultura da bananeira em Santa Catarina. Este trabalho teve como objetivo avaliar a eficiência de fungicidas e da desfolha no controle da Sigatoka em banana Prata. Foram testados seis tratamentos, combinando-se três formulações (Tebuconazole 0,5 L ha-1 - tiofanato metílico 0,6 L ha-1; Biomassa cítrica 1,0 L ha-1; água) com ou sem desfolha. As variáveis avaliadas foram área abaixo da curva de progresso (AACPD) e soma bruta final (SBfinal) da doença. O delineamento experimental foi blocos ao acaso em esquema fatorial com cinco repetições, comparados entre si pelo teste de Duncan (P 0,05). Foram verificadas diferenças significativas para as formulações, mas não para desfolha, em comparação com testemunha. Para o fator formulação verificou-se que os fungicidas e a biomassa cítrica proporcionaram reduções significativas da área abaixo da curva de progresso da doença (AACPD) e soma bruta final (SBfinal) em comparação com testemunha. Os fungicidas e a biomassa cítrica reduziram a área abaixo da curva de progresso em 65 e 63%, assim como a soma bruta final caiu 83 e 73% em comparação com testemunha, respectivamente. Não se verificou influência da desfolha no controle da sigatoka, porém outros estudos com aplicações mais freqüentes devem ser realizados para quantificar melhor seu efeito. Concluiu-se que os fungicidas e a biomassa cítrica são eficientes no controle da sigatoka.
Assuntos
Biomassa , Desfolhantes Químicos/análise , Desfolhantes Químicos/síntese química , CitrusRESUMO
This work was carried out in order to generate information on the tillering process and to contribute for the understanding of the defoliation process on Italian ryegrass (Lolium multiflorum Lam.) grazed by lambs under different herbage allowances: 6, 8 and12 kg of dry matter per100 kg of animal live weight per day. The grazing method was intermittent. The experimental design was completely randomized following a repeated measure arrangement, with three treatments and two area replications. The intensity of defoliation is greater at 6 and 9% herbage allowances. The defoliation interval is higher at 12% herbage allowance, intermediate at 9% and lower at 6%. The rates of tiller emergence, survival and death, stability index the tiller population are similar for the different herbage allowances and differ according to the phenological stage of ryegrass. Structural changes caused by canopy management with low herbage allowance and/or due to the advance in developmental stage of ryegrass alter defoliation strategies, with more intense and frequent grazing.(AU)
Este trabalho foi conduzido com o objetivo de gerar informações sobre o processo de perfilhamento e contribuir para com o entendimento do processo de desfolhação do azevém (Lolium multiflorum Lam.) utilizado por cordeiras, submetidas a diferentes ofertas de forragem: 6; 8 e 12 kg de MS 100-1 kg de peso corporal. O método de pastejo foi intermitente. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo, três tratamentos e duas repetições de área. A intensidade de desfolhação é superior nas ofertas de forragem 6 e 9%. O intervalo entre desfolhações foi superior na oferta de forragem 12%, intermediária na oferta 9% e inferior na oferta 6%. As taxas de aparecimento, sobrevivência e mortalidade de perfilhos e o índice de estabilidade da população de perfilhos são similares nas ofertas de forragem e variam nos estádios fenológicos do azevém. Mudanças estruturais do dossel causadas pelo manejo com baixas ofertas de forragem e/ou pelo avanço do estádio fenológico do azevém alteram as estratégias de desfolhação, com pastejo realizado de forma mais intensa e frequente.(AU)
Assuntos
Lolium/crescimento & desenvolvimento , Lolium/metabolismo , Desfolhantes Químicos/análiseRESUMO
This work was carried out in order to generate information on the tillering process and to contribute for the understanding of the defoliation process on Italian ryegrass (Lolium multiflorum Lam.) grazed by lambs under different herbage allowances: 6, 8 and12 kg of dry matter per100 kg of animal live weight per day. The grazing method was intermittent. The experimental design was completely randomized following a repeated measure arrangement, with three treatments and two area replications. The intensity of defoliation is greater at 6 and 9% herbage allowances. The defoliation interval is higher at 12% herbage allowance, intermediate at 9% and lower at 6%. The rates of tiller emergence, survival and death, stability index the tiller population are similar for the different herbage allowances and differ according to the phenological stage of ryegrass. Structural changes caused by canopy management with low herbage allowance and/or due to the advance in developmental stage of ryegrass alter defoliation strategies, with more intense and frequent grazing.
Este trabalho foi conduzido com o objetivo de gerar informações sobre o processo de perfilhamento e contribuir para com o entendimento do processo de desfolhação do azevém (Lolium multiflorum Lam.) utilizado por cordeiras, submetidas a diferentes ofertas de forragem: 6; 8 e 12 kg de MS 100-1 kg de peso corporal. O método de pastejo foi intermitente. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo, três tratamentos e duas repetições de área. A intensidade de desfolhação é superior nas ofertas de forragem 6 e 9%. O intervalo entre desfolhações foi superior na oferta de forragem 12%, intermediária na oferta 9% e inferior na oferta 6%. As taxas de aparecimento, sobrevivência e mortalidade de perfilhos e o índice de estabilidade da população de perfilhos são similares nas ofertas de forragem e variam nos estádios fenológicos do azevém. Mudanças estruturais do dossel causadas pelo manejo com baixas ofertas de forragem e/ou pelo avanço do estádio fenológico do azevém alteram as estratégias de desfolhação, com pastejo realizado de forma mais intensa e frequente.
Assuntos
Desfolhantes Químicos/análise , Lolium/crescimento & desenvolvimento , Lolium/metabolismoRESUMO
The spraying of coca (Erythroxylum coca) with glyphosate (coca mixture, a combination of formulated glyphosate, Glyphos, and an adjuvant, Cosmo-Flux) in Colombia has raised concerns about possible impacts on amphibians. Although acute LC50 for 8 species of Colombian frogs ranged from 1.2 to 2.78 mg acid equivalents (a.e.)/L, these exposures were conducted in the laboratory in the absence of sediments and organic matter such as would occur under realistic field conditions. In order to assess the effects of overspray of frog habitat under field conditions, Gosner stage 25 tadpoles of Rhinella granulosa, R. marina, Hypsiboas crepitans, and Scinax ruber were placed in outdoor microcosms made from polyethylene plastic fish ponds (2.07 m in diameter, 37 cm high) in an experimental area in Tolima, Colombia. The bottoms of the microcosms were covered with a 3-cm layer of local soil and they were filled to a depth of 15 cm (above the sediment) with local spring water. After up to 100 tadpoles of each frog species were placed in the microcosms, they were sprayed with the coca mixture at concentrations greater and less than the normal application rate (3.69 kg glyphosate a.e./ha). Mortality at 96 h in the control microcosms was between 0 and 16% and LC50 values were between 8.9 and 10.9 kg glyphosate a.e./ha (equivalent to initial concentrations of 5963 to 7303 microg glyphosate a.e./L). Mortality >LC50 was only observed in the tested species when the application rate was >2-fold the normal application rate. In other experiments, juvenile and adult terrestrial stages of frogs were exposed by direct spraying to a range of concentrations of coca mixture. Juveniles and adults were exposed in plastic food containers (19 x 19 cm). The bottom of the container was filled with moistened soil and leaf litter to a depth of 1 cm and 0.5 cm, respectively. Mortality in the controls was low, from 0 to 10%, and from 0 to 35% at the normal application rate. LC50 values ranged between 4.5 kg a.e./ha and 22.8 kg a.e./ha, 1.5- to 6-fold greater than the normal application rate. Data indicate that, under realistic worst-case exposure conditions, the mixture of Glyphos and Cosmo-Flux as used for control of coca in Colombia exerts a low toxicity to aquatic and terrestrial stages of anurans and that risks to these organisms under field conditions are small.
Assuntos
Anuros/fisiologia , Desfolhantes Químicos/toxicidade , Controle de Medicamentos e Entorpecentes/métodos , Glicina/análogos & derivados , Poluentes Químicos da Água/toxicidade , Adjuvantes Farmacêuticos/análise , Adjuvantes Farmacêuticos/toxicidade , Aeronaves , Animais , Desfolhantes Químicos/análise , Combinação de Medicamentos , Sedimentos Geológicos/química , Glicina/análise , Glicina/toxicidade , Larva/efeitos dos fármacos , Larva/fisiologia , Dose Letal Mediana , Modelos Biológicos , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Medição de Risco , Especificidade da Espécie , Tensoativos/análise , Tensoativos/toxicidade , Testes de Toxicidade Aguda , Poluentes Químicos da Água/análise , GlifosatoRESUMO
The Colombian amphibian fauna is among the richest known in the world, with about 20 species of salamanders (order Caudata), 35 of the limbless caecilians (order Gymnophiona), and more than 700 species of frogs and toads (order Anura) recorded from localities within the country. The potential effects of exposure to glyphosate on amphibians arising from production of illegal crops (coca) were examined. The analysis was based on (1) behavior and ecology of species and (2) proximities of actual museum records to localities in which illegal crops are being grown and the subset of those that have been sprayed with glyphosate. Based on data on the location of amphibians collected in Colombia, records were obtained for 193 species (28% of the national diversity) of frogs and toads found in localities within 10 km of areas where coca is grown. Further analyses with ARC MAP software allowed for measurement of the direct distance separating collection locations for frogs, known coca fields, and areas where aerial spraying was being conducted. Records in or near coca fields included data for 11 of 13 families of frogs and toads known to be present in Colombia. Only Ceratophryidae and Pipidae were not reported from these locations and appear not to be at risk. For eight species (Dendrobates truncatus, Craugastor raniformis, Pristimantis gaigeae, Smilisca phaeota, Elachistocleis ovale, Hypsiboas crepitans, Trachycephalus venulosus, and Pseudis paradoxa) selected to represent several habitat preferences and life-cycle strategies, large areas of their distributions lie outside coca production regions and their populations as a whole are at low risk. For a limited number of species that barely enter Colombian territory, the consequences of coca production may be more serious and may have placed several species of frogs at risk. These include Ameerega bilingua, Dendropsophus bifurcus, Pristimantis colomai, P. degener, P. diadematus, P. quaquaversus, P. variabilis, and Trachycephalus jordani. Other species may also be at risk but exact numbers are unknown since few investigations were undertaken in these areas during the past 30 yr. The main ranges for these species were assumed to be in Ecuador.