Emre Evlice

Fungal diseases represent a major constraint on global wheat production, necessitating the development of sustainable management strategies that integrate biological control agents. This study aimed to characterize the culturable fungal community in wheat rotation systems (wheat, barley, safflower, chickpea, lentil, and vetch) in Haymana (Ankara, Türkiye) and to evaluate the antagonistic potential of indigenous Clonostachys rosea isolates. A total of 19 fungal isolates were recovered from 25 soil samples and identified via ITS rDNA sequencing as C. rosea (6), Fusarium equiseti (6), Fusarium oxysporum (4), Fusarium redolens (1), Alternaria alternata (1), and Alternaria atra (1). To assess biocontrol efficacy, three representative C. rosea isolates were screened against the virulent pathogen Fusarium culmorum using dual-culture assays. All tested C. rosea isolates significantly inhibited the radial growth of F. culmorum. The highest inhibition rate was achieved by isolate CR11 (32.19%), followed by CR14 (26.82%) and CR15 (15.94%). These findings suggest that wheat ecosystems may host beneficial antagonists, such as C. rosea, which could contribute to the development of biologically based integrated disease management strategies.

Investigating alternatives to synthetic chemicals in pest management is essential. The bioactivity of Artemisia absinthium and A. dracunculus essential oils (EOs) was evaluated against two stored-product insect pests (Sitophilus granaries and Tribolium castaneum) and two root-knot nematodes (Meloidogyne incognita and M. chitwoodi). EOs were hydrodistilled and analyzed by GC-MS: A. absinthium consisted mainly of myrtenyl acetate (47.10%) and β-thujone (11.41%); A. dracunculus of methyleugenol (26.02%), β-asarone (14.04%), and elemicin (10.95%). In contact bioassays, A. absinthium caused 93.2–96.8% mortality against S. granarius, but minimal effect on T. castaneum. A. dracunculus caused 66.3–73.5% mortality against S. granarius, no effect on T. castaneum, yet reduced progeny by 87%. Both EOs strongly repelled T. castaneum but weakly affected S. granarius. A. dracunculus exhibited 100% nematicidal efficacy against M. incognita and 94.9% against M. chitwoodi; A. absinthium showed limited effect. A. dracunculus showed minimal hatching inhibition (A. absinthium increased hatching. Sparse Partial Least Squares (sPLS) prioritized pulegone, methyleugenol, β-asarone, β-thujone, myrtenyl acetate, and β-phellandrene as constituents co-varying with AChE/BChE responses, with docking identifying pulegone as the top ligand. These findings demonstrate species-specific bioactivity patterns: A. dracunculus shows strong nematicidal and reproductive inhibitory effects, whereas A. absinthium shows potent acute toxicity and repellency against S. granarius, supporting multi-target biopesticide strategies to mitigate risks of synthetic chemical treatments.

This study offers a comparative analysis of the chemical composition and multi-target bio-efficacy of essential oils (EOs) from Tanacetum balsamita (TB) and T. densum subsp. amani (TD), in accordance with sustainable agricultural practices and the pursuit of natural pesticide alternatives. GC-MS analysis identified a novel chemotype for TD, characterized by the predominance of diepicedrene-1-oxide (18.37%) and valencene (11.86%), a profile not previously reported in the literature. In contrast, TB was distinguished by its high concentration of oxygenated monoterpenes (78.81%), with carvone (41.38%) as the major constituent. Topical application assays (0.05–0.15 µL/insect) revealed significant dose effects for all insect species (p<0.05). At 0.15 µL/insect, TB caused 100% mortality of Rhyzopertha dominica within 24 h and of Sitophilus oryzae by 48 h, while TD achieved 93.3% and 98.9% mortality, respectively, at the same dose. Both oils were only moderately active against Tribolium castaneum, reaching 46.7% (TD) and 40.0% (TB) mortality at 72 h. Controls showed no mortality, whereas K-Obiol produced 100% mortality at all intervals. In nematode bioassays, TB induced 100% J2 mortality at 2 µL/mL at 96 h and retained near-complete activity at 1 µL/mL (99.1% at 24 h), but efficacy declined steeply at 0.5 µL/mL (45% at 96 h). TD exhibited time-dependent and limited nematicidal activity, reaching 39.8% mortality at 96 h (2 µL/mL). These results highlight chemotype-dependent potency and position TB EO as a promising multi-target botanical candidate for integrated pest management.

This study offers a comparative analysis of the chemical composition and multi-target bio-efficacy of essential oils (EOs) from Tanacetum balsamita (TB) and T. densum subsp. amani (TD), in accordance with sustainable agricultural practices and the pursuit of natural pesticide alternatives. GC-MS analysis identified a novel chemotype for TD, characterized by the predominance of diepicedrene-1-oxide (18.37%) and valencene (11.86%), a profile not previously reported in the literature. In contrast, TB was distinguished by its high concentration of oxygenated monoterpenes (78.81%), with carvone (41.38%) as the major constituent. Topical application assays (0.05–0.15 µL/insect) revealed significant dose effects for all insect species (p<0.05). At 0.15 µL/insect, TB caused 100% mortality of Rhyzopertha dominica within 24 h and of Sitophilus oryzae by 48 h, while TD achieved 93.3% and 98.9% mortality, respectively, at the same dose. Both oils were only moderately active against Tribolium castaneum, reaching 46.7% (TD) and 40.0% (TB) mortality at 72 h. Controls showed no mortality, whereas K-Obiol produced 100% mortality at all intervals. In nematode bioassays, TB induced 100% J2 mortality at 2 µL/mL at 96 h and retained near-complete activity at 1 µL/mL (99.1% at 24 h), but efficacy declined steeply at 0.5 µL/mL (45% at 96 h). TD exhibited time-dependent and limited nematicidal activity, reaching 39.8% mortality at 96 h (2 µL/mL). These results highlight chemotype-dependent potency and position TB EO as a promising multi-target botanical candidate for integrated pest management.

Ditylenchus dipsaci (Kühn, 1857) Filipjev, 1936 (Rhabditida: Anguinidae) is one of the destructive agents of garlic and reduces yield and market value. One of the most practical and eco-friendly methods for nematode management is using resistant varieties. In the study, two endemic garlic species, Allium tuncelianum (Kolman) Ozhatay, Mathew & Siraneci and Allium macrochaetum subsp. macrochaetum Boiss. & Hausskn. (Alliaceae: Amaryllidaceae), 10 mutant and 32 landraces garlic genotypes, Allium sativum L. (Alliaceae: Amaryllidaceae) were investigated for their resistance reactions to D. dipsaci and effect of D. dipsaci on some plant growth parameters. All experiments were conducted at Atatürk Horticultural Central Research Institute in 2019-2020. None of the genotypes was found resistant to D. dipsaci, and reproduction factors, which ranged from 2.6 to 12.7, were grouped from susceptible to highly susceptible. The Tunceli garlic genotype had the lowest reproduction factor (2.6), 36.6% less than the highly susceptible Muğla6 genotype. Alata1, Muğla1, Muğla7 and Kula genotypes had the lowest decrease rate with nematode treatment at least in one of the plant growth parameters. The genotypes that had lower nematode multiplication and displayed better development under nematode infestation in this study are recommended for the field infested with D. dipsaci as sources for garlic breeding.

Bu çalışmada kök-ur nematodlarının Batı Karadeniz Bölgesi kivi bahçelerindeki yaygınlık ve yoğunluklarının belirlenmesi amaçlanmıştır. Bu amaçla 2015 ve 2016 yıllarında Düzce (2), Zonguldak (3) ve Bartın (3) illerinde sekiz kivi bahçesinden kök ve toprak örnekleri alınmıştır. DNA ikinci dönem larvalardan ekstrakte edilmiş, ClearDetections firmasına ait M. tropical spp., M. hapla ve M. enterelobii real-time primerleri ve Meloidogyne spp. üniversal MF/MR primerleri moleküler teşhislerde kullanılmıştır. Çalışma sonucunda, bahçelerden %50’sinin Meloidogyne spp. ile bulaşık olduğu ve Bartın ve Zonguldak illerinden birer bahçenin M. incognita, Zonguldak ilinden bir bahçenin M. hapla ve Düzce ilinde bir bahçenin ise hem M. incognita hem de M. hapla ile bulaşık olduğu saptanmıştır. Bahçelerdeki popülasyon yoğunluğunun 31-252 J2/100 g toprak arasında değiştiği ve en yüksek popülasyon yoğunluğunun Bartın ili Yanaz Köyünde ağustos ayında 252 J2/100 g toprak olduğu belirlenmiştir.

Stem and bulb nematode, Ditylenchus dipsaci (Kühn, 1857) Filipjev, 1936 (Tylenchida: Anguinidae) is widely distributed in areas where garlic is grown commercially in Turkey. One of the suitable methods for control of D. dipsaci under field conditions is rotation with non-host plant species. Thus, it is necessary to determine the host status of the plant species that can be used in rotation with the garlic plant. For this purpose, the host status of eight different plant species for four D. dipsaci populations obtained from important garlic growing areas was investigated in 2017 and 2018. The experiments were conducted with four replicates of treatments with nematode and without nematodes in a control environment room. Each plant was inoculated with 200 nematodes of the respective population. Six weeks after inoculation, the final nematode population in the plants and reproduction factors were determined. For all nematode populations, daffodil was an excellent host with reproduction factor (Rf) of 5.0-6.2. Onion and garlic plants were good hosts with Rf of 3.2-3.8 and 2.1-2.5, respectively. Lucerne, chickpea, leeks, lettuce and wheat were determined to be non-host species with Rf 0.6-0.7, 0.5-0.8, 0, 0 and 0.3-0.5, respectively. It was concluded that these non-host plant species can be used as rotational crops in the garlic production areas infested with D. dipsaci. Soğan sak nematodu, Ditylenchus dipsaci (Kühn, 1857) Filipjev, 1936 (Tylenchida: Anguinidae) Türkiye’de ekonomik olarak sarımsak yetiştiriciliği yapılan üretim alanlarında yaygın olarak bulunmaktadır. Ditylenchus dipsaci‘nin tarla koşullarında mücadelesi için uygun yöntemlerden birisi de konukçu olmayan bitki türleri ile rotasyon uygulamalarıdır. Bu nedenle sarımsak bitkisi ile rotasyona girebilecek bitki türlerinin nematoda konukçuluk durumlarının belirlenmesi önem arz etmektedir. Bu amaçla çalışmada sekiz farklı bitki türünün önemli sarımsak yetiştirme alanlarından elde edilen dört farklı D. dipsaci popülasyonuna karşı konukçuluk durumları 2017-2018 yıllarında araştırılmıştır. Denemeler iklim odası şartlarında nematodlu ve nematodsuz bitkiler için dört tekerrürlü olarak yürütülmüştür. Nematodlu bitkilere bitki başına 200 nematod inokule edilmiştir. İnokulasyondan altı hafta sonra bitkilerdeki sonuç nematod popülasyonu belirlenerek üreme faktörleri belirlenmiştir. Çalışmada bütün nematod popülasyonları için, nergis bitkisi 5.0-6.2 arasında üreme faktörü (Rf) ile mükemmel konukçu olarak belirlenmiştir. Soğan ve sarımsak bitkileri sırasıyla 3.2-3.8 ve 2.1-2.5 Rf ile iyi konukçu olarak tespit edilmiştir. Yonca, nohut, pırasa, marul ve buğday bitki türleri sırasıyla 0.6-0.7, 0.5-0.8, 0, 0 ve 0.3-0.5, Rf değerleri ile konukçu olmayan bitki türleri olarak belirlenmiştir. Gerçekleştirilen bu çalışma ile konukçu olmayan bitki türlerinin soğan sak nematodunun bulaşık olan üretim alanlarında rotasyon bitkisi olarak kullanılabileceği sonucuna varılmıştır.

Patates kist nematodları (PKN) Altın kist nematodu olarak isimlendirilen Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959 ve Beyaz kist nematodu olarak isimlendirilen G. pallida Stone, 1973, tüm dünyada hemen hemen tüm patates alanlarında önemli verim kayıplarına neden olan yaygın türlerdir. Önemli karantina etmenleri olan PKN’nın doğru ve hızlı teşhisi mücadelesi açısından çok önemlidir. Bu iki türün oluşturduğu risk nedeniyle, Türkiye'de bu etmenlerin varlığı sertifikalı ve yemeklik patates alanlarında ulusal survey programı kapsamında taranmaktadır. Çalışma kapsamında Niğde, Nevşehir, İzmir, Afyon ve Bolu illerine ait 10 farklı lokasyondan elde edilen PKN popülasyonlarına ait kist ve ikinci dönem larvalar morfolojik ve morfometrik karakterlerine göre teşhis edilmiştir. Çalışma İzmir ili hariç diğer illerdeki G. rostochiensis popülasyonlarının ilk detaylı morfolojik ve morfometrik verilerini içermektedir. Çalışma sonucunda popülasyonların tamamı G. rostochiensis olarak teşhis edilmiştir. Türkiye’deki bulaşık alanların tamamını kapsayacak şekilde ilk kez yapılan bu çalışmayla ülkemizdeki G. rostochiensis popülasyonlarının morfolojik olarak teşhisinin yapılabildiği, ölçüm değerlerinin referans literatürlerle uyumlu olduğu belirlenmiştir. Ancak rutin analizlerde tüm dünyada en önemli karantina etmenlerinden biri olan Patates kist nematodlarının teşhisinde morfolojik ve moleküler yöntemlerinin bir arada kullanılmasının daha doğru olacağı düşünülmektedir.

The study was conducted to determine the occurrence, frequency and density of species of Meloidogyne Goeldi, 1892 (Tylenchida: Meloidogynidae) in ware potato cultivation areas of Turkey in Plant Protection Central Research Institute. Soil samples were taken from Afyonkarahisar (149), Aksaray (69), Bolu (94), Kayseri (94), Konya (127), Nevşehir (91), Niğde (226) and Sivas (77) Provinces in 2018-2019. Meloidogyne juveniles were extracted by modified Baarmenn funnel and counted under inverted microscope. Meloidogyne populations were identified by species-specific primers. Meloidogyne spp. were detected in 84 of 927 soil samples. Meloidogyne spp. was detected in Aksaray, Kayseri, Nevşehir, and Niğde while was not found Afyonkarahisar, Bolu, Konya, and Sivas Provinces. In survey areas, the occurrence of Meloidogyne chitwoodi Golden, O'Bannon, Santo & Finley, 1980 and Meloidogyne hapla (Chitwood, 1949) (Tylenchida: Meloidogynidae) was 8.7 and 1.5%, respectively. Also, M. chitwoodi and M. hapla mixed populations were found in 1.2% of samples. Mean density of Meloidogyne spp. J2s was determined as 182, 175, 162 and 90 J2s/100 ml of soil in Niğde, Nevşehir, Aksaray and Kayseri Provinces, respectively. In conclusion, important ware potato cultivation areas of Turkey were found to be infested with Meloidogyne spp., but the important seed potato-growing areas were found to be free of Meloidogyn e spp.