Biocontrole da mancha-angular do feijoeiro por antagonistas bacterianos

Abstract

(2) In memoriam Resumo -O objetivo deste trabalho foi avaliar o efeito de isolados de Bacillus cereus e Pseudomonas putida sobre a severidade da mancha-angular do feijoeiro, em condições de campo. Quatro experimentos foram conduzidos em épocas favoráveis à mancha-angular (Pseudocercospora griseola), com as cultivares Pérola e Ouro Negro. Os experimentos foram realizados em delineamento de blocos ao acaso, com seis repetições. Os tratamentos foram pulverizações sobre as plantas com três estirpes de B. cereus (UFV-172, UFV-101 e UFV-75) e duas estirpes de P. putida (UFV-53 e UFV-Pp), acibenzolar-S-metil, fungicida clorotalonil e controle pulverizado com água, no total de oito tratamentos. Os tratamentos foram aplicados por atomização no filoplano de plantas de feijoeiro, semanalmente, a partir do 15 o dia após a emergência até o fim do ensaio. Calculou-se a área abaixo da curva de progresso da mancha-angular do feijoeiro; a doença ocorreu naturalmente. A produção foi avaliada pela massa média de sementes por planta. Os antagonistas foram eficientes em reduzir a severidade da doença, em comparação à testemunha, e obtiveram o mesmo nível de controle do tratamento químico. O menor índice de severidade da doença propiciou melhor produção do que o tratamento controle.Termos para indexação: Bacillus cereus, Phaseolus vulgaris, Pseudocercospora griseola, Pseudomonas putida. Biocontrol of bean angular leaf spot by bacterial antagonistsAbstract -The objective of this work was to evaluate the effect of Bacillus cereus and Pseudomonas putida isolates on the severity of the angular leaf spot of common bean under field conditions. Four trials were carried out in favorable seasons to angular leaf spot (Pseudocercospora griseola), using the cultivars Pérola and Ouro Negro. The assays were assembled in a randomized block design with six replicates. The treatments were plant-sprayings with three strains of B. cereus (UFV-172, UFV-101 and UFV-75) and two strains of P. putida (UFV-53 and UFV-Pp), acibenzolar-S-methyl, chlorothalonil fungicide and the control with water, in a total of eight treatments. The treatments were applied weekly by spraying the phylloplane of bean plants, starting from the 15 th day after seedling emergency until the end of the assay. The area under the disease progress curve of the angular leaf spot was calculated; the disease occurred naturally. Yield was evaluated by the average seed mass per plant. The antagonists were effective in reducing the severity of the disease, in comparison to the control, and they had the same control level as the chemical treatment. The lowest index of the disease severity provided the best yield, in comparison to the control treatment.

Reaction of lima bean accessions to Meloidogyne javanica

“…However, Rio Grande do Sul also stands out in the national scenario, with a yield of 1,926 kg ha -1 year -1 , because of its better technology (IBGE 2015). The low crop yield is the result of several factors, such as the lack of adequate technology (Gomes et al 2016), absence of specific soil fertilization programs (Alves et al 2008) and presence of pests and diseases (Garcia & Romeiro 2011, Boechat et al 2014, Silva et al 2014. Nematodes, especially the root-knot ones, are responsible for high production losses in several crops.…”