Quantitative determination of alpha-tocopherol in Arbutus unedo by TLC-densitometry and colorimetry.

A quantitative determination of alpha-tocopherol in Arbutus unedo leaves was established by TLC-densitometry and colorimetry. Data obtained by TLC-densitometry were compared with those obtained by colorimetry. Also, the alpha-tocopherol content in leaves collected at different times of the year was studied comparatively. The highest amount of alpha-tocopherol was found in the March collection.     

Determination of agronomic practices for the management of blight of chickpea caused by <Emphasis Type="Italic">Ascochyta rabiei</Emphasis> in Turkey: 1. Appropriate sowing date

In order to determine the most appropriate dates for planting chickpea in central Anatolia, Turkey, six cultivars were planted at three sites that differed in disease pressure. In two of the sites, disease pressure from Ascochyta rabiei was promoted by spreading infected chickpea debris on the soil surface at the time of planting and, at one of these, sprinkle irrigation was applied. In the third site, where conditions were dryer, no artificial inoculum was provided. Plants from seeds sown in early March had the most disease and in the sprinkle irrigated plots the disease severity ranged from 7.8 on the most susceptible cv. Canitez to 3.3 on the least susceptible Gokce as scored on the 1–9 scale where 1 = no disease and 9 represents a plant killed by the fungus. There was an inverse relationship between disease severity and yield, production from blight resistant cultivars of around 2,000 kg ha⁻¹ being more than twice that of susceptible ones. Delaying planting for 3–5 weeks reduced the severity of ascochyta blight but also reduced the yields in four of the six cultivars. In contrast, reduction in disease severity by delayed sowing resulted in yield increases for the susceptible cvs Canitez and Local, although yield level was not as much as those of the less susceptible cvs sown early. Delay of 6–9 weeks almost eliminated ascochyta blight but yields of all cultivars were seriously compromised by drought stress. In consequence, chickpea farmers are recommended to use resistant or tolerant cultivars and sow early in March. For less resistant cultivars, sowing in early April is recommended. Further delay is not recommended unless irrigation is provided and fungicide spraying is recommended where signs of infection are present under conditions conducive to the disease.     

Fish oil replacement by different microalgal products in microdiets for early weaning of gilthead sea bream (Sparus aurata,L.)

The aim of this study was to determine if algal products rich in DHA or ARA are able to completely replace fish oil in microdiets for marine fish larvae, gilthead seabream and if extra supplementation with EPA may further enhance larval performance. For that purpose, 20 day‐old gilthead seabream larvae of 5.97 ± 0.4 mm mean total length and 0.12 ± 0.001 mg mean dry body weight were fed with five microdiets tested by triplicate: a control diet based on sardine oil; a diet containing AquaGrow^® DHA (diet DHA) to completely substitute the sardine oil; a diet containing AquaGrow^® ARA (diet ARA); a diet containing both products, AquaGrow^® DHA and AquaGrow^® ARA to completely substitute the fish oil; and, a diet containing both products, AquaGrow^® DHA and AquaGrow^® ARA, together with an EPA source. Temperature, air and salinity activity tests were also performed to detect larval resistance to stress. At the end of the experiment, final survivals did not differ among groups. The microorganism produced DHA was able to completely replace fish oil in weaning diets for gilthead seabream without affecting survival, growth or stress resistance, whereas the inclusion of microorganism produced ARA did not improve larval performance. Moreover, addition of EPA to diets with total replacement of fish oil by microorganism produced DHA and ARA, significantly improved growth in terms of body weight and total length. The results of this study denoted the good nutritional value of microorganisms produced DHA as a replacement of fish oil in weaning diets for gilthead seabream, without a complementary addition of ARA. However, dietary supplementation of EPA seems to be necessary to further promote larval performance.     

Determination of histological and genotoxic effects of formalin on Nile tilapia (Oreochromis niloticus L.)

Formalin (37–40% formaldehyde) is one of the most effective, widely used chemical in pisciculture for its antiparasitic, antifungal and prophylactic activities. It is used in paints, cleaning products and textile industry, as well. Genotoxic and histological effects of sublethal formalin exposure on Nile tilapia (Oreochromis niloticus) are investigated in this study. The semi‐static acute test was employed. One‐tenth, one‐fifth and half of the 96‐h LC₅₀ value, 148 mg L^?1, were used as sublethal exposure concentrations: 15, 30 and 75 mg L^?1 for 24, 48, 96 and 168 h respectively. The micronucleus test was applied to investigate the genotoxic effects on fish erythrocytes at the end of predetermined exposure periods and all tissues of the fish were sampled for histological examination. The micronucleus frequencies increased significantly in all exposure groups when compared with their control groups in a dose and time dependent manner (P < 0.05). Results of histological examination showed no histopathological findings in the gonads, heart, skeletal muscle, spleen and intestine tissues after sublethal formalin exposure. Passive hyperaemia of liver tissue in varying proportions, hydropic degeneration, fatty degeneration in high concentrations, branchitis on gill tissues in varying proportions, epithelial lifting, telangiectasia, bleeding in kidney and hyperaemia were found in Nile tilapia exposed to formalin at different concentrations and durations. As a result, it is thought that formalin leads to tissue damage and shows genotoxic effects even at 15 mg L^?1 concentration in O. niloticus.     

Response of cotton (Gossypium hirsutum L.) to different tillage systems and intra-row spacing

The earliness is of great importance to cotton production in Mediterranean-type environments due to detrimental effects of autumn rainfall on lint quality. However, farmers commonly avoid early sowing due to risks of cold soil temperature and waterlogging after sowing in spring. Ridge-tillage system is one approach to increase soil temperature and mitigate adverse effects of waterlogging. The ridge-tillage system is also advantageous in reducing inputs in tillage operations. However, a limited experimental data are available about the effects of ridge-tillage system on earliness of harvesting, lint yield and quality of cotton in the Mediterranean-type environments. Thus, the objective of this study was to determine how ridge-tillage (RT)-planting system and intra-row spacing affect cotton lint yield, earliness and fiber quality compared with conventional tillage (CT)-planting system. Field experiments were conducted on a clay soil (Vertisol) in Hatay province (36°39′N–36°40′E, 83 m a.s.l.) in the Eastern Mediterranean Region of Turkey during 2000 and 2001. The experiment was laid out as a split-plot with three replications with tillage systems as main plots and intra-row spacings (13, 17, 21 and 25 cm) as subplots. The effects of tillage systems on lint yield and earliness were inconsistent among years. The RT-planting system resulted in 13.5% higher lint yield and 14.5% more earliness in 2001 when abundant rainfall occurred after sowing, while significant effects of tillage systems were not observed in 2000. The intra-row spacings significantly affected lint yield and earliness in both years. The earliness increased with closer spacing, while the highest lint yield was obtained from 17 cm intra-row spacing in both years. However, the fiber quality parameters were not significantly affected by tillage systems, intra-row spacings and tillage system × spacing interaction in both years. Finally, the results suggest that RT-planting system with 17 cm intra-row spacing can be used in cotton production instead of CT-planting system in the Eastern Mediterranean Region of Turkey. Ridging in 17 cm intra-row spacing also seems to be suitable to mechanical harvesting.     

Use of Bioinoculants in Ameliorative Effects on Radish Plants Under Salinity Stress

The aim of this study was to evaluate the effect of plant growth promoting bacteria (PGPB) on emergence, growth, physiology, and mineral content of radish under salinity stress. The study was conducted in pot experiments using a mixture of soil: sand (1:1 v: v) under greenhouse conditions. Bacillus subtilis EY2, Bacillus atrophaeus EY6, and Bacillus spharicus GC subgrup B EY30 were isolated in highly salty soils in Upper Coruh Valley in Turkey. Seeds were soaked in the bacterial suspension incubated at 27°C for 2 h. Emergence percentage (EP) was reduced and mean emergence time (MET) raised with sodium chloride (NaCl) solutions. Inoculated seeds displayed greater EP and less MET compared to the non-inoculated ones. Salinity negatively affected growth of radish; however, plant growth promoting bacteria treatments positively affected growth parameters such as fresh weight (278% for shoot, 371% for root) and dry weights (250% for shoot, 422% for root) compared to non-treated plants that were challenged with salt stress. Furthermore, selected bacteria caused an increase in uptake of minerals except sodium (Na) compared to the non-treated controls in both salt stress and salt stress absence. Sodium concentration of plant leaves was increased by salt stress while bacterial inoculation decreased its concentration. Bacterial treatments increased chlorophyll content and decreased electrolyte leakage of plants in saline conditions. Leaf relative water content (LRWC) of plants in the salt stress condition increased with bacterial application, but reduced without bacterial application. The present study suggests that PGPB seed treatments can ameliorate the deleterious effects of salt stress on radish plants and PGPB could offer an economical and simple application to reduce problems of radish production in an Aridisol caused by high salinity.     

Antioxidant activity of Arbutus unedo leaves

The ethanol and methanol extracts of Arbutus unedo leaves were screened for antioxidant activity. The antioxidant activity was determined by an improved assay based on the decolorization of the radical monocation of [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS). The ethanol and methanol extract of A. unedo leaves displayed potent antioxidant activity.     

Effects of dietary mannan oligosaccharides in early weaning diets on growth,survival, fatty acid composition and gut morphology of gilthead sea bream (Sparus aurata,L.) larvae

Early weaning of marine fish larvae with dry diets delays gut maturation and reduces growth rates. In juvenile and adult forms of several marine fish species, inclusion of dietary mannan oligosaccharides (MOS) improves gut integrity and functionality, but the effects of MOS inclusion in gilthead sea bream (Sparus aurata, L.) larval diets have not been addressed yet. Thus, this study assesses the effects of dietary MOS inclusion on survival, growth performance, gut morphology, feed acceptance and quality of gilthead sea bream larvae. For that purpose, 16 days post‐hatched gilthead sea bream larvae were fed four graded levels of MOS (Biomos^®, Alltech, Nicholasville, KY, USA) in weaning diets as follows: 0 g kg^?1 MOS, 0.5 g kg^?1 MOS, 1.5 g kg^?1 MOS and 2 g kg^?1MOS. Dietary MOS did not affect feed acceptance in gilthead sea bream larvae (P > 0.05). MOS supplementation was correlated in a dose‐dependent way with higher larval survival (P = 0.026). After 15 days of feeding, dietary MOS increased whole larvae (P < 0.01) arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid. Gilthead sea bream larvae fed 2 g kg^?1 MOS presented higher gut occupation with goblet cells after feeding compared with larvae fed the other dietary treatments. Overall, the results suggest that inclusion of MOS in early weaning diets for gilthead sea bream improves essential fatty acid utilization and may promote growth and final survival.     

An SMS based system for surveillance of wheat rust diseases: a pilot initiative in Central Anatolia region in Turkey

Rust diseases (Puccinia spp.), namely stripe, leaf and stem rusts, are among the major diseases of wheat. Their management requires integrated approaches including timely surveillance, speedy communication and rapid response. This surveillance system was developed in order to facilitate participation of extension offices (in provinces/districts) in the survey of wheat rust diseases and sharing of information quickly. The SMS based system was tested as a pilot tool in the Central Anatolia region of Turkey connecting 25 districts in 5 provinces through an SMS network during the rust development period (April–July) in 2013. The observations from 268 fields indicated that leaf rust and stem rust development was insignificant in the districts covered, occurring in only 2.3% and 1.9% of the fields respectively. Stripe rust prevalence was higher occurring in 44.8% of the fields. Of the inspected fields 2.5% had infected plant incidences between 15% and 40% requiring control measures. Using the SMS reports received from the extension officers, the system facilitated daily monitoring of rust development and exchange of observations among the relevant institutions, also sending out alert messages to designated authorities as necessary. The study demonstrated that the system can serve as a rapid surveillance and communication tool to facilitate timely decision making and rapid response to prevent wheat rust epidemics.