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Hegazi E.M.,Alexandria University | Konstantopoulou M.A.,Greek National Center For Scientific Research | Herz A.,Institute for Biological Control | Khafagi W.E.,Egyptian Plant Protection Res Institute | And 5 more authors.
Insect Science

Prays oleae Bern, (OM) and Palpita unionalis Hüb., (JM) are two of the most important pests in olive groves in Egypt. A 3-year monitoring study using sex pheromone traps in semi-arid and arid olive groves was performed. In the semi-arid grove, flight pattern of the OM was the same as in other Mediterranean countries, but in dates concordating plant phenology. The moth completes three generations annually: the first flight is in March to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi-arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi-arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi-arid one. This study shows that trapping location and fruit bearing year are characteristics that strongly affect the grove-specific information needed to estimate correctly adult emergence and thus the timing of control measures. © 2011 The Authors Journal compilation © Institute of Zoology, Chinese Academy of Sciences. Source

Scherf A.,Institute for Biological Control
Communications in agricultural and applied biological sciences

In organic cucumber production infection with downy mildew (Pseudoperonospora cubensis) is a major problem. Plant extracts from Glycyrrhiza glabra L. (licorice), a plant belonging to the family Fabaceae, and Salvia officinalis (sage) as well as cultures of the bacterium Aneurinibacillus migulanus were investigated for efficacy of disease control under commercial growing conditions. Contrary to bioassays, where sage extract and the microorganism showed highest activity, in the trials of 2008 G. glabra extract was more effective than sage extract or A. migulanus against P. cubensis. Parameters such as concentrations of the preparations or application intervals could have been the reason for this. In the following year's trial (2009) the concentration of these agents was therefore increased somewhat and plants were either treated in seven day application intervals or in ten day application intervals. In the semi-commercial trials of 2009 all alternative biological agents showed good efficacies up to around 80% against infection with downy mildew. The application interval seemed to have a marginal effect only. Again, the licorice extract tended to be the best agent. Source

Koch E.,Institute for Biological Control | Schmitt A.,Institute for Biological Control | Stephan D.,Institute for Biological Control | Kromphardt C.,Institute for Strategies and Technology Assessment in Plant Protection | And 12 more authors.
European Journal of Plant Pathology

The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems. © 2010 KNPV. Source

Moharam M.H.A.,Sohag University | Leclerque A.,Institute for Biological Control | Koch E.,Institute for Biological Control

Despite the economic importance of covered kernel smut of sorghum (Sporisorium sorghi) in many African states and other parts of the world, only limited information is available on laboratory cultivation methods for this fungus and techniques for its diagnosis in plant tissue. The current paper describes laboratory and greenhouse experiments performed with field material of S. sorghi. When intact sori were kept at 5°C, 80% of the spores germinated even after 24 months of storage. Spore germination on agar medium and production of mycelial dry weight in still culture were highest between 20° and 35°C, with a peak at 30°C. Both showed a steady increase from pH 4. 5 to pH 7. 5, followed by a decline at pH 8. 5 and 9. 5. In shake culture in different broth media the addition of 0. 3% peptone from soybean caused an increase in fungal growth compared with the media alone. Of the media tested, mycelial production was highest in malt dextrose broth supplemented with peptone. When cultivated on different agar media, the morphology of single spore isolates differed both among isolates and depending on the agar medium. In greenhouse experiments, five short, early maturing sorghum breeding accessions proved to be partially or fully resistant to covered kernel smut. Among the plant materials tested, cv. 'Dorado' appeared to be the one best suited for greenhouse experiments with covered kernel smut. By microscopy of hand-cut sections stained with trypan-blue, hyphae of S. sorghi were seen in apical buds and in nodes of young sorghum plants. Diagnostic PCR amplified a 903 bp element comprising the internal region of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) encoding gene and enabled the detection of S. sorghi in both nodes and apical buds of infected sorghum seedlings. Both techniques, i. e., microscopy and diagnostic PCR, have the potential to be used in studies for the identification of effective sorghum seed treatments already at the seedling stage. © 2012 Springer Science + Business Media B.V. Source

Hegazi E.M.,Alexandria University | Konstantopoulou M.A.,Greek National Center For Scientific Research | Khafagi W.E.,Egyptian Plant Protection Res Institute | Schlyter F.,Swedish University of Agricultural Sciences | And 4 more authors.

Jasmine moth (JM), Palpita unionalis (Hübner) (Lepidoptera: Pyralidae) is a very important pest in the commercial, densely planted olive orchards in Egypt. In years of its highest population density, it can destroy a significant part of the crop. The objectives of this study were to determine the male flight trend and egg laying trend of the JM in three large plots of different olive varieties (two varieties/plot) in two successive fruiting seasons. Differences in male flight trend and egg laying trend of JM were observed among the different varieties ('Sennara', 'Toffahi', 'Shamy'). In 2003, more males were captured in traps placed in the Sennara/Toffahi plot than in the two Shamy/Toffahi plots. Egg densities were higher on Toffahi trees grown between Sennara trees than on Toffahi trees grown between Shamy ones. In 2004, in the plot where Toffahi and Sennara were grown together, JM females laid more eggs than in the olive plot where Toffahi rows alternated with Shamy rows. The results suggest that the Shamy variety discouraged gravid females from ovipositing, compared with Toffahi or Sennara varieties. In conclusion, olive variety, cropping system (mixed culture) and trapping season are among those characteristics that affect this pest. © 2012 Springer Science + Business Media B.V. Source

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