Foliar resorption in Quercus petraea subsp. iberica and Arbutus andrachne along an elevational gradient

? The resorption of nutrients (mainly N and P) from senescing leaves may be a key component of adaptive mechanisms that conserve scarce nutrients. Resorption may be expressed in two ways as resorption efficiency (RE) which is the ratio of the resorbed amounts of nutrient losses during leaf senescence in relation to its prior amount deposited in leaves and resorption proficiency (RP) is the level to which nutrient concentration per unit leaf mass is reduced in senescent leaves.

? There is still much debate whether or not different life-forms (i.e. deciduous and evergreen species) show different foliar resorption patterns. Two sympatric species, namely Quercus petraea (Mattuschka) Liebl. subsp. iberica (Steven ex Bieb.) Krassiln. (deciduous) and Arbutus andrachne L. (evergreen) along an elevational gradient were compared with each other to determine whether or not nitrogen and phosphorus resorption efficiency and proficiency varies along the elevational gradient and which leaf parameters were as related to RE and RP.

? NRE was found to be rather low in Q. petraea subsp. iberica compared to other deciduous species. Similarly, PRE in A. andrachne was rather low compared to other evergreen species. Mean residence time (MRT) measures how long a unit of nitrogen (MRT_N) and phosphorus (MRT_P) is present in the plant. MRT_N and MRT_P were found to be considerably higher in A. andrachne compared to Q. petraea subsp. iberica. In both species, the foliar N/P ratio was below 14 along the elevational gradient and, according to this threshold value, N-limitation occurred in the study area. Although both species in the present study show incomplete resorption deciduous species was more proficient as compared to evergreen one due to low N and P concentrations in senescent leaves. Based on the significant correlations (p < 0.05 and 0.01) between MRT and foliar resorption, it can be concluded that MRT could interfere with the mechanisms controlling nutrient resorption.

     

Use of different plastics for soil solarization in strawberry growth and time–temperature relationships for the control of <Emphasis Type="Italic">Macrophomina phaseolina</Emphasis> and weeds

The aim of this study was to determine the effect of soil solarization on soilborne diseases, weeds and plant yields by using polyethylene film (30-μm-thick) containing different additives [ultraviolet (UV), ultraviolet + infrared (UV + IR), ultraviolet + infrared + anti-fog + anti-dust (UV + IR + AF + AD)], and used polyethylene film (260-μm-thick). Trials were conducted in commercial strawberry (Fragaria ananassa cv. ‘Camarosa’) fields in the town of Sultanhisar in Aydin province, Turkey, between 2007 and 2009. The highest soil temperatures at the depth of 10 cm under a polyethylene sheet containing UV + IR + AF + AD were 54°C in 2007 and 50.7°C in 2008. During the 2007 growing season, collapse and death of strawberry plants were not detected. At the end of the 2008 season (May–June), collapsed and dying strawberry plants were observed. Pure cultures of Macrophomina phaseolina and Rhizoctonia solani were isolated from affected roots and crowns of plants. Viability studies of M. phaseolina were conducted under various field conditions and temperatures and M. phaseolina sclerotia survived more than 18 days at 45°C. There was a sharp decline in M. phaseolina at 50°C, where it survived for 19 h but was completely killed at 20 h. It first lost viability after 17 h at 50°C and after 60 min at 55°C. In the field, solarization did not reduce the viability of M. phaseolina at a soil depth of 10 or 20 cm; however, a significant reduction (66%) in survival was determined at a soil depth of 5 cm. All treatments controlled Portulaca oleracea, Amaranthus spp., Digitaria sanguinalis, Echinochloa crus-galli, Veronica hederifolia, Raphanus raphanistrum, Setaria verticillata and Mercurialis annua at a rate of 100%, but no treatment was effective on Cyperus rotundus. The marketable fruit yield was 38,004 kg.ha⁻¹ for UV + IR, 35,834 kg.ha⁻¹ for UV-added polyethylene film and 35,368 kg.ha⁻¹ for used polyethylene sheet-covered plots, whereas it was 27,365 kg.ha⁻¹ for untreated control plots.     

Employing pheromone traps to establish the distribution and seasonal activity of Theresimima ampellophaga in Turkey

The vine bud moth, Theresimima ampellophaga (Bayle-Barelle 1808) (Lepidoptera: Zygaenidae; Procridinae), is a pest on grape vine, Vitis vinifera (L.), and on the ornamental vine Parthenocissus quinquefolia (L.) and other Parthenocissus species. Its recent distribution in Europe is relatively well known, but there is a paucity of locality data for Turkey. As a consequence, we began a large-scale investigation into its distribution and seasonal activity in this country in 2008. The main tools for these investigations were pheromone traps that were baited with the synthetic pheromone of the species, viz. (2R)-butyl (Z7)-tetradecenoate. As a result of field work carried out in the eastern Mediterranean region of Turkey in 2008 and 2009, Th. ampellophaga was recorded in five provinces, viz. Adana, Mersin, Hatay, Kahramanmara? and Kilis. The only province where the pest was not found was Gaziantep. Theresimima ampellophaga produces one or two generations per year, depending on the local conditions and other unknown factors. The moths of the first generation fly in June, while those of the second generation occur in August. To the best of our knowledge the present paper provides the first well-documented evidence of the occurrence of a second generation of the vine bud moth in Turkey.     

Verticillium wilt of olive in Turkey: a survey on disease importance,pathogen diversity and susceptibility of relevant olive cultivars

A comprehensive survey on the prevalence and incidence of Verticillium wilt of olive in Turkey has been conducted over 6 years (2003–2008). Vegetative compatibility group (VCG) assessment and PCR-based molecular pathotyping were used to evaluate the distribution of the defoliating (D) and nondefoliating (ND) pathotypes of Verticillium dahliae in surveyed areas. Pathogen prevalence was 35% of all olive orchards inspected and incidence of the disease reached 3.1%. VCG1A was predominant (29.3%) and infected all major cultivars grown in Turkey. The other two VCGs detected (2A and 4B) were of minor relevance (4.9% and 0.9%, respectively). Disease incidence caused by VCG1A infections was higher (ranging from 1.1% to 6.9%) than that caused by VCG2A and VCG4B in 10 provinces (Manisa, Aydin, Kahramanmaras, Izmir, Mugla, Kilis, Denizli, Gaziantep, Mardin and Balikesir). However, VCG2A and 4B were more prevalent (and responsible for higher disease incidence) than VCG1A in three provinces (Hatay, Osmaniye and Bursa). Finally, VCG1A isolates were found in all provinces except Canakkale, and simultaneous presence of the three VCGs was only verified in Hatay province. An artificial inoculation bioassay (19 representative V. dahliae isolates included) revealed that VCG1A (13) isolates as a group were more aggressive and caused defoliation, whereas VCG2A (5) and VCG4B (1) isolates induced milder symptoms. Within a VCG group, virulence varied among isolates infecting the same olive cultivar and this virulence was also related to the differential susceptibility of the cultivars (‘Manzanilla’, ‘Ayvalik’ and ‘Gemlik’) tested. Molecular pathotyping allowed the identification of D (VCG1A) and ND (VCG2A/4B) pathotypes, which correlated with results from pathogenicity tests. Remarkably, the V. dahliae VCG1A/D pathotype population infecting olive in Turkey was molecularly different from that one previously identified in Spain.     

Plant canopy effects on litter accumulation and soil microbial biomass in two temperate forests

The objective of this study was to determine whether differences in canopy structure and litter composition affect soil characteristics and microbial activity in oak versus mixed fir-beech stands. Mean litter biomass was greater in mixed fir-beech stands (51.9t ha⁻¹) compared to oak stands (15.7t ha⁻¹). Canopy leaf area was also significantly larger in mixed stands (1.96m² m⁻²) than in oak stands (1.73m² m⁻²). Soil organic carbon (C _org) and moisture were greater in mixed fir-beech stands, probably as a result of increased cover. Soil microbial biomass carbon (C _mic), nitrogen (N _mic), and total soil nitrogen (N _tot) increased slightly in the mixed stand, although this difference was not significant. Overall, mixed stands showed a higher mean C _org/N _tot ratio (22.73) compared to oak stands (16.39), indicating relatively low rate of carbon mineralization. In addition, the percentage of organic C present as C _mic in the surface soil decreased from 3.17% in the oak stand to 2.26% in the mixed stand, suggesting that fir-beech litter may be less suitable as a microbial substrate than oak litter.     

The effect of Rhizobium spp. inoculation on seed quality of bean in Turkey

Rhizobium spp. (local isolate) was used to inoculate three bean (Phaseolus vulgaris L.) varieties; Akman 98, G?ynük 98 and Sehirali 90, in a factorial field experiment. The objective of the experiment was to study effect of inoculation on seed yield, protein range, seed weight, non-soaker capacity and hydration index. Rhizobium spp. inoculation and nitrogen fertilizer significantly increased characters tested. This study revealed that inoculation with Rhizobium spp. improved seed quality.     

An artificial neural network approach to prediction of the colorimetric values of the stripped cotton fabrics

This paper presents an artificial neural network (ANN) modeling by Levenberg-Marquardt (LM) algorithm for predicting the colorimetric values of the stripped cotton fabrics dyed using commercial reactive dyes. Achieving the expected efficiency in the application of stripping process is a very important aspect for the success of the reproduction. In the study, the predictions of L* and ΔE colorimetric values of stripped cotton samples for different stripping applications by artificial neural network are reported. We set up different network structures with different number of nodes in the hidden layer, the number of inputs and MSE of results as stopping criteria in order to get the best fitting model. According to the result of the best neural network models predicting L* and ΔE, we achieved 97 % of R for both of them. We are able to predict the L* value of the stripped samples using some working parameters as inputs with only 1.2 % error. We think that our results are very promising and the predictions of L* and ΔE values of stripped samples before applying any process are possible using the ANN model set up in the study, especially for L*.     

Characterization of Cement Plant Emissions in Turkey

In cement plants in Turkey CO, NO₂, SO₂ and particulate emissions were measured using standard measurement techniques and equipment. Emission factors are calculated by dividing the emission rates by capacity of production at the time of measurements for each plant. The results of this study show that the dominant emissions from cement production in Turkey is CO followed by NO₂, dust and SO₂ in decreasing order. National averages for the emission factors are calculated and compared to international emission factors. On average the Turkish dust emission factor is higher than the German factor, however NO₂ and SO₂ emission factors are lower in Turkey.     

Effect of stocking density on growth performance of juvenile sea cucumber Holothuria tubulosa (Gmelin, 1788)

Stock density is one among the most important factors in aquaculture that directly influences the growth of organisms; however, there is limited information about the effects of stocking density on growth performance of sea cucumber Holothuria tubulosa (Gmelin, 1788) that has a commercial potential and represents a new species for aquaculture. In this study, we investigated the effect of stocking densities on the growth performance of juvenile H. tubulosa (40.3 ± 3.34 g) in laboratory conditions. Stocking densities were selected as 6, 15 and 30 ind m^?2 with total biomass 253.3 ± 0.18, 601.2 ± 0.11 and 1201.4 ± 0.15 g m^?2 respectively. We monitored the growth by wet weights and calculated the growth performance through weight gain, growth rate, specific growth rate, relative weight gain, coefficients of variation and survival rate during 8 weeks of research period. We found that individual mean weight gain in 6 ind m^?2 group was approximately 29.53 g while it was 3.03 g and ?4.36 g for 15 ind and 30 ind m^?2 groups respectively. Results have shown that the specific growth rate tends to decrease as the number of individuals in unit area increases. The final mean weight, growth rate, specific growth rate, relative weight gain and coefficients of variation were significantly different among treatment groups. In conclusion, a density of 6 ind m^?2 is recommended for stocking juvenile H. tubulosa under rearing conditions. Stocking density of 15 ind m^?2 is not favourable for long term as the growth rate is negligible where 30 ind m^?2 should be avoided in tank‐based rearing units.