Two-spotted mite, Tetranychus urticae Koch (Arac.: Tetranychidae), is an economic pest worldwide including Turkey, causing serious damage to vegetables, flowers, and fruit crops. In recent years, broad-spectrum insecticides/miticides have been used to control this pest in Turkey. Control is difficult mainly due to resistance to conventional pesticides. This study was conducted to determine efficacy of pesticides extracted from five different plants [i.e., Allium sativum L. (Amaryllidaceae), Rhododendron luteum S. (Ericaceae), Helichrysum arenarium L. (Asteraceae), Veratrum album L. (Liliaceae), and Tanacetum parthenium L. (Asteraceae)] against this mite. Bioassays were tested by two different methods to determine the effects of varying concentrations. Experiments were performed using 3 cm diameter leaf disk from unsprayed bean plants (Phaseolus vulgaris L.). In addition, the effects of the extracts on reproduction and oviposition were investigated. The extract yielded high mortality. In the lowest-concentration bioassays, the adult mites laid lower numbers of eggs compared to the untreated control. No ovicidal effect was observed.

Tbe distribution of important plant-parasitic and free-living nematodes in tbe cereal production areas of tbe Central Anatolian Plateau (CAP) of Turkey was investigated witb systematic surveys. Two important plant-parasitic nematode groups were found widely distributed; cereal-cyst nematodes (78.3%) and root-lesion nematodes (42.6%). Cereal cyst nematodes (CCN) were identified as Heterodera filipjevi in 18 provinces. Heterodera latipons was found in only one province. Pratylenchus thornei and P. neglectus were tbe most widely distributed species of root-lesion nematodes. Otber frequently recorded plant-parasitic nematodes belonged to tbe genera Geocenamus (52.4%), Pratylenchoides (35.6%), Helicotyienchus (29.7%) and Paratylenchus (19.2%). Konya on tbe soutbern CAP bad a significantly bigb incidence of P. neglectus as well as free-living nematodes. Tbe incidence of CCN was greatest in areas of sandy soils on tbe CAP, witb densities of up to 95 cysts (100 g soil)"'. Population densities of Geocenamus, Pratylenchus and Pratylenchoides were bigb in some locations. Soil pbysicocbemical properties were investigated for tbeir relationship to nematode distribution. Tbere was a sligbt positive correlation of P. thornei and clay content; conversely, there was a significant negative correlation of P. negiectus witb clay and a positive correlation witb sand. Electrical conductivity (EC) was positively correlated witb P. neglectus. Nematodes in tbe genera Heiicotylenchus, Paratylenchus, Trophurus and Tylenchorhynchus were only recorded at low population densities in tbe sampled area. By contrast, nematodes in tbe genera Aphelenchus, Apheienchoides, Dityienchus, Dorylaimus, Tylenchus and bacterivorous genera bad relatively bigb populations. Total free-living nematodes were positively correlated witb EC and zinc (Zn) concentration. Tbe Zn content of soil was generally at a level deficient for plant growtb.

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In July 2009, a leaf blotch disease was observed on sorghum in Sakarya Province, Turkey. Disease incidence and severity were rated at 45% and 25 to 75%, respectively. Typical symptoms included elliptical, straw-colored, necrotic lesions with darker margins. The lesions eventually coalesced, resulting in drying of leaves. A fungus was isolated from the lesions on potato dextrose agar (PDA) incubated under near ultraviolet light for 12 h daily at 22°C for 2 weeks. Flexuous conidiophores of the fungus were solitary or produced in small groups. They were geniculate with numerous well-defined scars, medium to dark brown, ≥300 μm long, and 4 to 9 μm thick. Five to eight or more conidia were produced on the apices of the conidiophores. The conidia were straight, oblong or cylindrical, rounded at the ends, golden brown at maturity except for a small area just above the dark scar, pseudoseptate, and 20 to 31 × 7.5 to 12.5 μm (1). The causal fungus was identified as Bipolaris spicifera (Bain) Subram. (teleomorph Cochliobolus spicifer Nelson). The identification was confirmed with specific PCR primers (Bipol-1 F: 5′-CAGTTGCAATCAGCGTCAGT-3′, R: 5′-AAGACAAAAACGCCCAACAC-3′, Bipol-2 F: 5′-GTGTTGGGCGTTTTTGTCTT-3′, R: 5′-CCTACCTGATCCGAGGTCAA-3′, Bipol-3 F: 5′-GATGAAGAACGCAGCGAAAT-3′, R: 5′-AAGACAAAAACGCCCAACAC-3′). These primers were designed by the authors using Primer3 primer design software and sequences of B. spicifera found in GenBank. PCR products were amplified from nuclear DNA of the cultured fungus and were sequenced after cleaning with a Beckman 8000 CEQ DNA sequencer. Sequences amplified using Bipol-1 and Bipol-2 showed 99 to 100% similarity with B. spicifera sequences from GenBank. The DNA sequence amplified using Bipol-2 was deposited in GenBank (Accession No. HQ538774). B. spicifera has been reported previously as pathogenic in Africa, North and South America, Asia, Australia, Oceania, and the West Indies on Agrostis, Avena, Cymbopogon, Cynodon, Dactylis, Desmostachya, Eleusine, Holcus, Hordeum, Oryza, Panicum, Pennisetum, Phleum, Poa, Saccharum, Sorghum, Triticum, and Zea spp. (3). Pathogenicity tests were conducted on sorghum (Sorghum bicolor (L.) Moench) and Sorghum × sudangrass hybrid cultivars. From PDA cultures, conidia were collected in sterile distilled water with a concentration of 3% Tween 20. Twenty-five plants (five per pot) were inoculated by spraying the conidia (105 ml–1) onto 21-day-old plants, which were then maintained at 25 ± 2°C in a greenhouse following 48 h in a humid chamber. The test was repeated once. Control plants were sprayed with sterile distilled water. Typical symptoms (2) were obtained from all inoculated plants 7 days after inoculation. No symptoms developed on the control plants. The pathogen was reisolated from inoculated leaves to fulfill Koch's postulates. To our knowledge, this is the first report of B. spicifera on sorghum in Turkey. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, England, 1971. (2) H. Koo et al. Plant Pathol. J. 19:133, 2003. (3) A. Sivanesan. Mycologia Papers 158:1, 1987.