Prorjeđivanje plodova jabuke sorte \u27Gala\u27 pomoću ethephona, NAA i BA te njihovih kombinacija

The thinning response was studied on six years old trees of ‘Gala’/M.9. The treatments of single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter as well as the sequential treatments of ethephon followed by NAA or/and BA and tank mixed NAA + BA treatment were performed. A non significant thinning was obtained in treatments when ethephon, NAA and BA were used separately. No additional thinning occurred even in the combinations when ethephon was applied first at the balloon stage and NAA or BA applied later at 10 mm fruitlet diameter. Significant thinning response occurred only when tank mixed treatment of NAA + BA and sequential treatment of ethephon followed by tank mixture of NAA + BA were carried out. In this experiment, mean fruit weight and the share of bigger sized fruits (>70mm) increased significantly in all thinning treatments compared to the non thinned control trees.Proučavali smo odaziv prorjeđivanja na šest godina starim stablima sorte \u27Gala\u27/M.9. Izvedeni su postupci pojedinačnih aplikacija etefona 200 ppm u fenofazi crvene glavice, naftiloctene kiseline (NAA) 10 ppm ili benziladenina (BA) 100 ppm kada je promjer ploda iznosio 10 mm kao i uzastopni postupci etefonom nakon čega je slijedila NAA, odnosno BA ili u tanku pomiješani NAA + BA. Prorjeđivanje nije bilo signifikantno kod postupaka, u kojima su etefon, NAA i BA primijenjeni pojedinačno. Do dodatnog prorjeđivanja nije došlo ni u postupcima kada je etefon primijenjen najprije u balonskom stadiju, a NAA ili BA primijenjeni kasnije, kada je promjer plodova iznosio 10 mm. Signifikantan odaziv na prorjeđivanje dogodio se samo kada je izveden postupak s u tanku pomiješanim NAA + BA i uzastopni postupak etefonom nakon čega su slijedili u tanku pomiješani NAA + BA. U tom pokusu prosječna težina plodova i udio većih plodova (> 70 mm) signifikantno su se povećali kod svih postupaka prorjeđivanja u usporedbi s neprorjeđivanim stablima kontrole

Prorjeđivanje plodova jabuke sorte \u27Gala\u27 pomoću ethephona, NAA i BA te njihovih kombinacija

The thinning response was studied on six years old trees of ‘Gala’/M.9. The treatments of single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter as well as the sequential treatments of ethephon followed by NAA or/and BA and tank mixed NAA + BA treatment were performed. A non significant thinning was obtained in treatments when ethephon, NAA and BA were used separately. No additional thinning occurred even in the combinations when ethephon was applied first at the balloon stage and NAA or BA applied later at 10 mm fruitlet diameter. Significant thinning response occurred only when tank mixed treatment of NAA + BA and sequential treatment of ethephon followed by tank mixture of NAA + BA were carried out. In this experiment, mean fruit weight and the share of bigger sized fruits (>70mm) increased significantly in all thinning treatments compared to the non thinned control trees.Proučavali smo odaziv prorjeđivanja na šest godina starim stablima sorte \u27Gala\u27/M.9. Izvedeni su postupci pojedinačnih aplikacija etefona 200 ppm u fenofazi crvene glavice, naftiloctene kiseline (NAA) 10 ppm ili benziladenina (BA) 100 ppm kada je promjer ploda iznosio 10 mm kao i uzastopni postupci etefonom nakon čega je slijedila NAA, odnosno BA ili u tanku pomiješani NAA + BA. Prorjeđivanje nije bilo signifikantno kod postupaka, u kojima su etefon, NAA i BA primijenjeni pojedinačno. Do dodatnog prorjeđivanja nije došlo ni u postupcima kada je etefon primijenjen najprije u balonskom stadiju, a NAA ili BA primijenjeni kasnije, kada je promjer plodova iznosio 10 mm. Signifikantan odaziv na prorjeđivanje dogodio se samo kada je izveden postupak s u tanku pomiješanim NAA + BA i uzastopni postupak etefonom nakon čega su slijedili u tanku pomiješani NAA + BA. U tom pokusu prosječna težina plodova i udio većih plodova (> 70 mm) signifikantno su se povećali kod svih postupaka prorjeđivanja u usporedbi s neprorjeđivanim stablima kontrole

Diagnostics of fruit trees phytoplasmas – the importance of latent infections

In the period 2000-2008 more than 1300 fruit trees from different regions of Slovenia were tested for the quarantine phytoplasmas Apple proliferation (AP), Pear decline (PD), and European stone fruit yellows (ESFY). The majority of samples were collected within systematic official surveys, which was conducted for assessing the presence of these phytoplasma in Slovenia in production and mother plant orchards. Samples were taken from trees with and without expressed symptoms. DNA was extracted from the symptomatic shoots. In addition some roots from asymptomatic trees were sampled for the evaluation of latent infections. The presence of phytoplasmas was analyzed with a nested PCR, RFLP and a real time PCR (Hren et al., 2007). AP, PD and ESFY were confirmed as being present in several areas in Slovenia where fruit trees are cultivated. AP was found not only in apple, but also in stone fruit trees such as cherry, apricot and plum (Mehle et al., 2007). By using highly sensitive diagnostic methods, such as real time PCR, some latent infections were detected and they were confirmed next year also by less sensitive methods.Keywords: Phytoplasma, AP, PD, ESFY, latent infection, fruit tree

Assessment of deep cryogenic heat-treatment impact on the microstructure and surface chemistry of austenitic stainless steel

This systematic study deals with the influence of deep cryogenic treatment (DCT) on microstructure and surface properties of austenitic stainless steel AISI 304 L on different length scales and in the surface region. The study incorporates different analysis techniques, such as light microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), electron backscatter diffraction (EBSD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ions mass spectrometry (ToF-SIMS). DCT modifies the microstructure of treated samples through promoted precipitation of Cr7C3 carbides, induced twinning and α-martensite formation. Additionally, XPS/AR-XPS and ToF-SIMS results also provide evidence of modified oxidation dynamics of DCT samples compared to conventionally heat-treated samples with increase of the Fe-oxide fraction and lower Cr-oxide fraction in the surface oxide layer. An evaluation of oxidation states and ions distribution within the surface layer of deep cryogenically heat-treated stainless steel AISI 304 L is conducted with XPS/ToF-SIMS. These results are correlated with the microstructural changes and nitrogen diffusivity induced by DCT, which are associated with modified oxidation behaviour of AISI 304 L. These results provide further understanding of DCT dynamic on the overall microstructure and the corresponding surface behaviour

Annihilation of edge dislocations in smectic A liquid crystals

This paper presents a theoretical study of the annihilation of edge dislocations in the same smectic plane in a bulk smectic-A phase. We use a time-dependent Landau-Ginzburg approach where the smectic ordering is described by the complex order parameter psi( r--> ,t) =eta e(iphi) . This quantity allows both the degree of layering and the position of the layers to be monitored. We are able to follow both precollision and postcollision regimes, and distinguish different early and late behaviors within these regimes. The early precollision regime is driven by changes in the phi ( r--> ) configuration. The relative velocity of the defects is approximately inversely proportional to the interdefect separation distance. In the late precollision regime the symmetry changes within the cores of defects also become influential. Following the defect collision, in the early postcollision stage, bulk layer order is approached exponentially in time. At very late times, however, there seems to be a long-time power-law tail in the order parameter fluctuation relaxation

Silicon carbide diodes for neutron detection

In the last two decades we have assisted to a rush towards finding a He3-replacing technology capable of detecting neutrons emitted from fissile isotopes. The demand stems from applications like nuclear war-head screening or preventing illicit traffic of radiological materials. Semiconductor detectors stand among the stronger contenders, particularly those based on materials possessing a wide band gap like silicon carbide. We review the workings of SiC-based neutron detectors, along with several issues related to material properties, device fabrication and testing. The paper summarizes the experimental and theoretical work carried out within the E-SiCure project, co-funded by the NATO SPS Programme. Among the achievements, we have the development of successful Schottky barrier based detectors and the identification of the main carrier life-time-limiting defects in the SiC active areas, either already present in pristine devices or introduced upon exposure to radiation fields. The physical processes involved in neutron detection are described. Material properties as well as issues related to epitaxial growth and device fabrication are addressed. The presence of defects in as-grown material, as well as those introduced by ionizing radiation are reported. We finally describe several experiments carried out at the Jozef Stefan Institute TRIGA Mark II reactor (Ljubljana, Slovenia), where a set of SiC-based neutron detectors were tested, some of which being equipped with a thermal neutron converter layer. We show that despite the existence of large room for improvement, Schottky barrier diodes based on state-of-the-art 4H-SiC are closing the gap regarding the sensitivity offered by gas-based and that of semiconductor detectors

Annihilation of edge dislocations in smectic A liquid crystals

This paper presents a theoretical study of the annihilation of edge dislocations in the same smectic plane in a bulk smectic-A phase. We use a time-dependent Landau-Ginzburg approach where the smectic ordering is described by the complex order parameter psi( r--> ,t) =eta e(iphi) . This quantity allows both the degree of layering and the position of the layers to be monitored. We are able to follow both precollision and postcollision regimes, and distinguish different early and late behaviors within these regimes. The early precollision regime is driven by changes in the phi ( r--> ) configuration. The relative velocity of the defects is approximately inversely proportional to the interdefect separation distance. In the late precollision regime the symmetry changes within the cores of defects also become influential. Following the defect collision, in the early postcollision stage, bulk layer order is approached exponentially in time. At very late times, however, there seems to be a long-time power-law tail in the order parameter fluctuation relaxation