Ação De Fungicidas No Controle Da Queima Das Folhas E Nas Características Físico-Química Da Cenoura Cv. Nantes

Abstract

RESUMOO presente trabalho teve por objetivo avaliar a ação dos fungicidas mancozeb (Dithane NT -3 kg/ha), metiram (Polyram DF -3 kg/ha), azoxistrobina (Amistar WG -100 g/ha), metiram + piraclostrobina (CabrioTop -2 kg/ha) e piraclostrobina (Comet -400 mL/ha) no controle da queima das folhas (Alternaria dauci) e sobre alguns parâmetros agronômicos e físico-químicos da cenoura cultivar Nantes. Os produtos foram pulverizados a cada sete dias, a partir dos 40 dias após a semeadura (DAS), totalizando cinco pulverizações durante o ciclo da cultura. A severidade da doença foi avaliada aos 45, 52, 59, 66 e 73 DAS para determinação da área abaixo da curva do progresso de doença e por ocasião da colheita, aos 105 DAS, foram determinados os parâmetros agronômicos (comprimento, diâmetro médio e o peso) e físico-químicos (firmeza, acidez titulável, sólidos solúveis, sacarose e açúcares redutores) das raízes. Foi constada maior eficácia no controle da doença para a aplicação de metiram + piraclostrobina e piraclostrobina e raízes mais pesadas para piraclostrobina. Houve incremento no teor de sólidos solúveis das raízes para os tratamentos azoxistrobina, metiram + piraclostrobina e piraclostrobina. Não foi constado efeito da aplicação dos fungicidas sobre o comprimento, diâmetro médio, firmeza, acidez titulável, teores de sacarose e de açúcares redutores das raízes. Palavras-chave: Daucus carota, Alternaria dauci, fungicida, pós-colheita FUNGICIDE ACTION IN THE CONTROL OF LEAF BLIGHT AND THE CARROT CV. NANTES PHYSICAL-CHEMICAL CHARACTERISTICS ABSTRACTThe objective of present study is to evaluate the action of the fungicides mancozeb (Dithane NT -3 Kg/ha), metiram (Polyram DF -3 Kg/ha), azoxistrobin (Amistar WG -100 g/ha), metiram + pyraclostrobin (CabrioTop -2 Kg/ha) and pyraclostrobin (Comet -400 mL/ha) in the control of leaf blight (Alternaria dauci), as well as their effects on some agronomical and physicalchemical parameters of the carrot cultivar Nantes. The plants were sprayed every seven days, starting 40 days after planting, and totaling five sprayings during their growing cycles. The severity of the disease was evaluated 45, 52, 59, 66, and 73 days after planting in order to determine the agronomical parameters (length, average diameter, and weight) and the physicalchemical characteristics (firmness, titratable acidity, soluble solids, sucrose and reduced sugars) of the roots. Applications of metiram + pyraclostrobin and pyraclostrobin, and this was found to be most effective in controlling the disease and on heavier carrot roots to pyraclostrobin. An increase in the level of soluble solids in the roots was observed with treatments of azoxistrobin, metiram + pyraclostrobin and pyraclostrobin. No effects were observed on the length, mean diameter, firmness, titratable acidity, and levels of sucrose and reduced sugars in the roots as a result of fungicide applications.

Effect of various fungicides in the control of Alternaria leaf blight in carrot crops

“…from the results obtained bySIVIERO et al. (2004), but was consistent with those of MARINGONI et al(2012).It is noteworthy that, in addition to reducing the severity of diseases, strobilurins and carboxamides have been reported to increase productivity and the quality of production. These positive effects on plant physiology are mainly attributed to the increase in chlorophyll content (green effect), increase in nitrate reductase enzyme activity, increase in antioxidant production, and the decrease in ethylene production.…”

“…Todos os fungicidas reduziram significativamente a severidade e o progresso da doença em relação à testemunha. Fluxapiroxade+piraclostrobina (0.3 L p.c./ha) destacou-se sendo superior a boscalida+cresoxim metílico (0.5 L p.c./ha, hidróxido de cobre (1.5 kg p.c./ ha) e azoxistrobina (0.12 kg p.c./ha), porém semelhante ao piraclostrobina+metiram In general, the strobilurins pyraclostrobin and azoxystrobin are considered effective in the control of the Alternaria leaf blight in carrot crops (FARRAR et al, 2004, DORMAN, 2009MARINGONI et al, 2012). In the present study, the application of pyraclostrobin mixed with metiram resulted in a control similar to the carboxamides and better than azoxystrobin.…”

Alternative Control of Alternaria Brown Spot in Tangerine

“…The treatment with the fungicides pyraclostrobin and trifloxystrobin are efficient to control the disease, since the losses caused by the disease are less than 50% compared to the control treatment [25]. Marigoni [26] verified the efficacy of the pyraclostrobin fungicide in controlling Alternaria in carrot leaves, with an area under the disease progress curve (AACPD) being found in 41.92 when treated with pyraclostrobin and 89.09 without any treatment (control), which resulted in a larger area to perform photosynthesis, consequently greater production and translocation of carbohydrates, thus showing greater weight of the roots when treated with pyraclostrobin. Tofoli [27] found that the fungicide pyraclostrobin + methiram inhibited 100% of conidia production and up to 80.4% of mycelial growth of Alternaria solani.…”

Avaliação Do Efeito Da Incorporação De Subprodutos Agroindustriais Na Elaboração De Cookies

“…A cenoura (Daucus carota L.), raiz tuberosa pertencente à família Umbelliferae, é uma hortaliça de grande importância econômica para o Brasil. É consumida in natura ou industrializada e excelente fonte de minerais e vitaminas para nossa alimentação (MARINGONI et al, 2012).…”