abstract the pythium spp. are known as the principle agents of seedling blight, damping-off and root rot of cucurbits. this study was performed for determination of pythium species involved in this diseases as well study their pathogenecity on different cucurbits. the numerous samples were taken at cultivation seasons 2006- 2007 from the fields of cucumber, tomato, egg plant, muskmelon, cucurbi...

Twenty-one species belonging to ten genera of zoosporic fungi were recovered from 23 surface water samples collected from ponds of accumulated rainfall in the Riyadh region (Saudi Arabia) using sesame seeds as baits at 20 ± 2 C. The most common genera were Allomyces (3 species), Aqualinderella (I species), Dictyuchus (2 species) and Pythium (3 species). The remaining six genera were less freque...

Susceptibility tests were conducted using the World Health Organization diagnostic test procedure on strains of Aedes taeniorhynchus, Aedes sollicitans, Aedes vexans, and Culex nigripalpus collected from several localities in Charleston and Georgetown counties of South Carolina. Aedes taeniorhynchus was resistant to malathion (mortality 1.0-54.4%) but not to propoxur, permethrin, or fenitrothio...

The interaction between Trichoderma harzianum and the soilborne plant pathogen Pythium ultimum was studied by electron microscopy and further investigated by gold cytochemistry. Early contact between the two fungi was accompanied by the abnormal deposition of a cellulose-enriched material at sites of potential antagonist penetration. The antagonist displayed the ability to penetrate this barrie...

A new species of Pythium collected from grapevine roots (Vitis vinifera) in South Africa and roots of common beet (Beta vulgaris) in Majorca, Spain, is described. The phylogenetic position of the new species was investigated by multigene sequence analyses of the internal transcribed spacers (ITS1 and ITS2) of the rDNA region, as well as three other nuclear and three mitochondrial coding genes. ...

The importance of rainfall for the development of Aedes vexans arabiensis populations, one of the potential vectors of Rift Valley Fever in West Africa, was demonstrated in a two-year follow-up study conducted in the Ferlo region of Senegal. In 2003, the rainy season began with heavy rains and, as a result, temporary ponds, the breeding places for mosquitoes, were flooded at their maximum level...

This paper presents an analysis of the interaction between the various variables associated with Rift Valley fever (RVF) such as the mosquito vector, available hosts and rainfall distribution. To that end, the varying zones potentially occupied by mosquitoes (ZPOM), rainfall events and pond dynamics, and the associated exposure of hosts to the RVF virus by Aedes vexans, were analyzed in the Bar...

Eggplant (Solanum melongena) is an important solanaceous vegetable crop in Bangladesh. The average yield of eggplant in the country is quite low. Among the various factors responsible for the low yield, phomopsis blight caused by Phomopsis vexans is the most devastating disease. When the leaves and twigs are infected, they become blighted and fruits get rotten and become mummified (Meah, 2003)....

A new species of Pythium isolated from wheat and apple roots in eastern Washington is described. Pythium abappressorium sp. nov. is characterized by abundant appressoria. Plerotic oospores and sporangia are formed from the appressoria and remnants of the appressoria remain attached to the base of sporangia at maturity. Smaller appressorial swellings, reminiscent of hyphal swellings, are also fo...