Black-foot (BF) disease of grapevines in nurseries and young vineyards is caused by soilborne Cylindrocarpon-like asexual morphs. They can be found both in symptomatic and asymptomatic vines, being spread to new grape growing areas during vineyard establishment. In this study, 42 grapevine nurseries located in different geographical regions in Turkiye were surveyed in 2021 to determine the presence of BF pathogens on asymptomatic marketable plants.Black-foot fungi were isolated from the roots or basal ends of asymptomatic dormant vines in 39 of them (92.9%). The percentage of isolation of BF pathogens ranged from 1.4 to 51.4% (average 18.4%). Seven species: Cylindrodendrum alicantinum, Cylindrocladiella peruviana, Dactylonectria macrodidyma, D. novozelandica, D. torresensis, Ilyonectria liriodendri, and I.2 robusta were identified based on DNA sequencing of histone H3 gene and phylogenetic analyses, D. torresensis being the most frequent. From these species Ca. peruviana, D. novozelandica and I. robusta were detected for the first time on grapevines in Turkiye. Pathogenicity tests on 1103P rootstock cuttings revealed that all species significantly decreased root biomass and increased root disease severity index, when compared with the non-inoculated control, D. novozelandica being the most virulent. Pathogenicity of Cm. alicantinum to grapevine was confirmed for the first time, thus this species should be included as causal agent of BF of grapevines. These findings point out that BF pathogens are highly prevalent in asymptomatic nursery produced grapevines and could represent a serious threat for Turkish viticulture.

No abstract

This study investigated the sheet erosion that occurs as a result of log skidding operations using a farm tractor on skid trails and the use of wood chips and slash in order to minimize the soil loss. A total of four blocks (sample fields) were formed in four designated skid trails in the study area and three runoff plots were established in each block. One of the runoff plots was left empty as a control (CNT). Wood chips (C) was placed in the second plot and logging residue slash (S) in the third. A total of 108 water samples were taken from the test sites, 36 from each of the control, wood chips and slash plots. The water samples were brought to the laboratory and placed in an heating oven. After the runoff water was evaporated, the remaining sediment was weighed on a sensitive scale. The specified value was calculated according to the total amount of runoff accumulated in the storage tank and the total suspended sediment it carried. As a result, the amount of the average runoff in the CNT was determined as 6.32 mm/m², in the C as 6.13 mm/m² and in the S as 6.03 mm/m². The average amount of suspended sediment transported in the CNT was found as 2.58 g m^-2, in the C as 1.61 g m^-2and in the S as 2.13 g m^-2. Therefore, the amount of soil loss in the control plots was about 1.2 times higher than in the slash plots and 1.6 times higher than in the wood chips plots. In this study, variance analysis results showed a statistically significant difference between the suspended sediment quantities carried from the plots (p <0.05). This study demonstrated that logging residues can be used to reduce the sheet erosion that occurs in skid trails after log extraction.

Bu araştırmada, 2011-2012 öğretim yılında ilk defa uygulamaya konulan 12. Sınıf Fizik Dersi Öğretim Programının, öğretmen görüşleri alınarak bilimsel içerik, öğrenme ve öğretme süreci (ders işleme stratejileri), hazırlık ve değerlendirme boyutları açısından değerlendirilmesini amaçlanmaktadır. Araştırmaya katılan fizik öğretmenlerine,"Fizik Dersi Müfredatı Değerlendirme Anketi" (FDMDA) uygulanmıştır. FDMDA, içerik, öğrenme ve öğretme süreci, hazırlık ve değerlendirme olmak üzere üç alt başlık altında toplam 46 maddeden oluşmaktadır. Sonuçlara göre, öğretmenlerin bilimsel içerik, hazırlık ve değerlendirme etkinlikleri açısından paralel düşüncelere sahip oldukları ancak bazı noktalarda da ayrıldıkları görülmektedir. Ayrıca, öğretme ve öğrenme sürecine ilişkin de bazı önemli bulgular ortaya konulmuştur.

No abstract