Albino Grigoletti Junior

Produtos alternativos no controle do oídio em mudas de eucalipto

Eucalypt plays an important role in Brazilian forestry because of its good adaptation, fast growth, high productivity, as well as a lot of good qualities for industry. Eucalyptus reforestation needs a continuous production of seedlings, which can be attacked by Oidium sp. The control of powdery mildew is based on fungicides, but for eucalypts there are no products commercially registered. The objective of this work was to evaluate chemical products, essential oils, plants extracts, milk and dairy products and antagonist for the alternative control of this disease. Seedlings of E. benthamii Maiden & Cambage were used in the assays. Disease severity was assessed using a scale varying from 0 (no symptoms) to 4 (severe symptoms) and calculated the area under progress disease curve (AUDPC). It was verified that the lowest AUDPC values of powdery mildew were obtained with piraclostrobin + epoxyconazol, and cow milk and Lecanicillium sp. were the best alternative products.

Crescimento in vitro de isolados de Armillaria sp. obtidos de Pinus elliottii var. elliottii sob várias temperaturas

ABSTRACT Armillaria root rot is the major pine disease in Brazil. Symptoms ofthis disease are yellowing of the needles, decline, root rot, resin exsudationand plant death. Temperature is an environmental factor that affectspathogens, the disease or both. This work evaluated the behaviour ofthree isolates of Armillaria sp. obtained from P. elliottii var. elliottii. Gomes, N.S.B.; Auer, C.G.; Grigoletti Junior, A. In vitro growth of Armillaria sp. isolates obtained from Pinus elliottii var. elliottii under severaltemperatures. Summa Phytopathologica , v.33, n.2, p.187-189, 2007.Additional keywords: fungal physiology, pathogen, root rot. The fungus isolates were submitted to temperature ranging from 16 to26 oC, by using dry biomass production in liquid medium as a measureablevariable. All isolates produced higher amount of biomass at 22 °C. A cubicregression showed a maximum point of temperatures between 21,8 e 23,2°C. The best temperature for fungus isolates growth was around 22 oC. RESUMO