ABSTRACT
The present study assessed the efficacy of formulated biocontrol agents and nitrogen fertilization on southern blight control. Antagonism test in vitro was performed to assess the inhibitory activity of Bacillus methylotrophicus and Trichoderma asperellum against the growth of Sclerotium rolfsii. Tomato seedlings were transplanted into the substrate added with ammonium nitrate doses and inoculated with the formulated biocontrol agents Ônix (B. methylotrophicus) or Quality (T. asperellum). Subsequently, seedlings were inoculated with S. rolfsii. Plant mortality, shoot and root weight were assessed 11 days after the last inoculation. Agents had effective inhibitory activity against S. rolfsii; thus, they could reduce southern blight severity when combined with ammonium nitrate. However, plant mortality was not reduced by them.(AU)
Subject(s)
Bacillus , Trichoderma , Solanum lycopersicum , In Vitro Techniques , Pest Control, Biological , Ammonium CompoundsABSTRACT
The study aimed to evaluate the control of Conyza bonariensis in delayed post-emergence stage using different spray nozzles and solutions with and without adjuvants; and to verify the occurrence of resistance to glyphosate, determining the dose-response curve. The experimental design was randomized in factorial (6 spray nozzles x 5 spray solution) in twenty repetitions. The treatments were represented by spray nozzles: XR 110015 XR 11002, TT 11002 AIXR 11002, AIC 11002 and AI 11002. Tested spray solution were: glyphosate; glyphosate + Nimbus®; glyphosate + Agral®; Glyphosate + LI-700® and without herbicide application. The use or not of adjuvants in the spray solution did not differ statistically from the solution containing the herbicide only. The spray nozzles AIXR 11002, TT 11002 and XR 11002 presented best results of control the horseweed from the evaluation of 07 days after application (DAP) and 28 DAP and such spray nozzles maintained the best average of control percentage. The higher dry matter reductions of horseweed were obtained by spray nozzles 110015 XR, TT 11002 and 11002 XR compared with the control. The population evaluated presents biotypes that resist to doses of 2.880 g.ha-1 a.e. of glyphosate. It is concluded that the evaluated biotypes presents tolerance to glyphosate, independent of your association or not with adjuvants.
O estudo teve como objetivo avaliar o controle de Conyza bonariensis no estádio pós-emergência tardia, empregando diferentes pontas e caldas com e sem adjuvantes; e verificar a ocorrência de resistência ao glyphosate, determinando a curva dose resposta. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial (6 pontas de pulverização x 5 caldas de pulverização) em vinte repetições. Os tratamentos foram representados pelas pontas de pulverização: XR 110015, XR 11002, TT 11002, AIXR 11002, AIC 11002 e AI 11002. As caldas testadas foram: glyphosate; glyphosate + Nimbus®; glyphosate + Agral®; glyphosate + LI-700® e sem aplicação do herbicida. O uso ou não de adjuvantes na calda não diferiram estatisticamente da calda contendo somente o herbicida. As pontas AIXR 11002, TT 11002 e XR 11002 apresentaram melhores resultados de controle da buva a partir de 07 dias após a aplicação (DAP) e aos 28 DAP e tais pontas mantiveram as melhores médias de porcentagem de controle nas demais avaliações. As maiores reduções de massa seca de buva foram obtidas pelas pontas XR 110015, TT 11002 e XR 11002 quando comparada com a testemunha. A população avaliada apresenta biótipos que resistem a doses de 2.880 g.ha-1 de e.a. do glyphosate. Conclui-se que os biótipos avaliados apresentam tolerância ao glyphosate, independente de sua associação ou não com os adjuvantes.