Época da aplicação de misturas de herbicidas em arroz irrigado

This investigation was carried out both in greenhouse and field conditions in order to evaluate the influence of Molinate + Propanil, Oxadiazon + Propanil, Thiobencarb + Propanil and Butachior + Propanil formulations, applied pre, during and post-emergence, on Bluebelle rice cultivar performance. The speed of emergence index, initial stand and shoot dry weight at twenty eight days after-sowing (in greenhouse) and the weed control and grain yield On field), were studied. According to the results the Butachlor + Propanil herbicide delayed the seedlings emergence and reduced the shoot dry matter content, but had no effect on the initial stand. There was no influence of the other herbicides on the same parameters. The best weed control and grain yield were obtained with Molinate + Propanil and Thiobencarb + Propanil application during emergence; Oxadiazon + Propanil and Butachlor + Propanil had similar performance either during and post-emergence application.Estudou-se, em campo e em casa-de-vegetação, a influência das seguintes misturas de  herbicidas no desempenho do arroz (Oryza sativa L.) cv. Bluebelle, aplicadas antes, durante e após a emergência: "Propanil + Molinate", "Propanil + Oxadiazon", "Propanil + Thiobencarb" e "Propanil + Butachlor". Foram estudados o índice de rapidez de emergência, a população inicial e o peso seco das plântulas aos 28 dias após a semeadura (em casa-de-vegetação) e o controle de inços e produção de grãos (em campo). Os resultados mostraram que o herbicida "Propanil+ Butachlor" retardou a emergência e reduziu o peso seco das plântulas, porém não influenciou na população inicial. As outras misturas não influenciaram na população nem no peso de matéria seca. O melhor controle aos inços e os melhores rendimentos foram obtidos com as aplicações de "Propanil + Molinate" e "Propanil + Thiobencarb" na emergência, bem como de "Propanil+ Oxadiazon" e "Propanil+ Butachlor" na emergência e dez dias após a emergência

Immature stages of Spodoptera albula (walker) (Lepidoptera: Noctuidae): developmental parameters and host plants.

This study aimed to detail the temporal and morphological parameters of the immature stages of Spodoptera albula (Walker 1857) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase) and to gather information about their larval host plants. For this purpose, a new rearing method and artificial diet was employed and validated. The viability of the egg, larval, pupal and pre-pupal stages was 94.54, 97.33, 93.84 and 92.34%, respectively. The average duration of the egg, larval, pupal and pre-pupal stages was 4.14, 16.37, 1.69, and 9.34 days, respectively. During the larval stage, 80.85% of females and 93.99% of males passed through six and remaining through seven instars, with significant larval protandry. The larvae that developed through six and seven instars exhibited a mean growth rate of 1.58 and 1.48, respectively. Fifty five host plant species belonging to 29 families are listed. The female pupae were significantly larger, exhibiting protogyny. Both the rearing methods as well as the larval diet proved adequate, providing more detailled observations of the biological cycle, especially the larval stage, and resulting in an overall survival of almost 80%