An Alternative Sucker Management Method in Hazelnut: Application of Nitrogen Fertilizer Solution

The goal of this study was to determine the usability of nitrogen solution for hazelnut sucker management. This study was carried out from 2015 to 2016?at two hazelnut orchards; one established with the shrub (ocak) system in Atakum district and the other established with the multi-stemmed system in the Carsamba district, both in Samsun province. For sucker management, 21% ammonium sulphate (AS) and 26% calcium ammonium nitrate (CAN) fertilizer solutions were used. Doses of 0, 10, 15 and 20% of solutions for both fertilizers were tested. In the study, hazelnut suckers were removed by knife in July 2015 and March 2016. Nitrogen solution applications were started in September 2015 when suckers reached 20–30?cm length. In 2016 four applications were made from April to August. Fifteen days after the applications, the wilting ratio (starting from the tip) and newly emerged suckers per bush were determined. Nitrate, pH, and EC analyses were made with soil samples collected at the beginning of the experiment and compared to those taken 15 days after each application. As a result, a 10% dose of 21% ammonium sulphate fertilizer gave the best results for hazelnut sucker management. Nitrogen solution application should be started 1 to 1.5 months after removal of suckers by cutting with a knife. Suckers should be removed when they reach 15–20?cm length and before they are lignified. For effective sucker management, nitrogen solution application should be applied at least three times in a year.

     

Growth and mortality of Mediterranean mussel Mytilus galloprovincialis Lam., 1819, in relation to size on longline in Mersin Bay, Izmir (Turkey – Aegean Sea)

The growth and mortality rate of different size of mussels, Mytilus galloprovincialis, were compared in Mersin bay, Izmir. Mussel sampling was performed on a monthly basis over 1 year, together with hyrobiological parameters. Water temperature, salinity, chlorophyll a, total particulate matter (TPM) and particulate organic carbon (POC) were determined. Average chlorophyll a, TPM and POC values were 3.88±1.62 μg L⁻¹, 13.12±3.68 mg L⁻¹ and 252±121.89 μg L⁻¹ respectively. Initial mean lengths of mussels for each size group were 10 mm (9.91±0.25 mm), 20 mm (20.14±0.29 mm), 30 mm (30.66±0.21 mm), 40 mm (40.14±0.21 mm), 50 mm (50.62±0.21 mm), 60 mm (59.77±0.21 mm) and 70 mm (69.47±0.62 mm). Maximum growth in length occurred during the spring–summer months. The annual length increments of mussel size groups were 46.22, 41.42, 30.3, 28.03, 20.63, 16.34 and 12.03 mm from small to large size groups respectively. Small mussels grew faster than large mussels and reached commercial size at the same time. Mortality was <5% for all groups at the end of the experiment.     

Faecal Indicator Bacteria: Groundwater Dynamics and Transport Following Precipitation and River Water Infiltration

Faecal contamination of drinking water extracted from alluvial aquifers can lead to severe problems. River water infiltration can be a hazard for extraction wells located nearby, especially during high discharge events. The high dimensionality of river?Cgroundwater interaction and the many factors affecting bacterial survival and transport in groundwater make a simple assessment of actual water quality difficult. The identification of proxy indicators for river water infiltration and bacterial contamination is an important step in managing groundwater resources and hazard assessment. The time resolution of microbial monitoring studies is often too low to establish this relationship. A proxy-based approach in such highly dynamic systems requires in-depth knowledge of the relationship between the variable of interest, e.g. river water infiltration, and its proxy indicator. In this study, continuously recorded physico-chemical parameters (temperature, electrical conductivity, turbidity, spectral absorption coefficient, particle density) were compared to the counts for faecal indicator bacteria, Escherichia coli and Enterococcus sp. obtained from intermittent sampling. Sampling for faecal indicator bacteria was conducted on two temporal scales: (a) routine bi-weekly monitoring over a month and (b) intense (bi-hourly) event-based sampling over 3 days triggered by a high discharge event. Both sampling set-ups showed that the highest bacterial concentrations occurred in the river. E. coli and Enterococcus sp. concentrations decreased with time and length of flow path in the aquifer. The event-based sampling was able to demonstrate differences in bacterial removal between clusters of observation wells linked to aquifer composition. Although no individual proxy indicator for bacterial contamination could be established, it was shown that a combined approach based on time-series of physico-chemical parameters could be used to assess river water infiltration as a hazard for drinking water quality management.