Multi-wavelength, all-solid-state, continuous wave mode locked picosecond Raman laser

We demonstrate the operation of a cascaded continuous wave (CW) mode-locked Raman oscillator. The output pulses were compressed from 28 ps at 532 nm down to 6.5 ps at 559 nm (first Stokes) and 5.5 ps at 589 nm (second Stokes). The maximum output was 2.5 W at 559 nm and 1.4 W at 589 nm with slope efficiencies up to 52%. This technique allows simple and efficient generation of short-pulse radiation to the cascaded Stokes wavelengths, extending the mode-locked operation of Raman lasers to a wider range of visible wavelengths between 500 - 650 nm based on standard inexpensive picosecond Nd:YAG oscillators

Numerical and Species Composition of Insects Transmitting Viral Infection in North Ossetia

One of the major tasks in the production of original and elite potato seeds is to prevent the rapid re-infection of the healthy material with viruses in the open field. The high rate of infection with each subsequent reproduction reduces seed productivity and worsens the tuber varietal quality. Currently, about two dozen viruses that infect potatoes have been identified. In the field, most of the harmful viruses of potatoes are transmitted by insects such as aphids, cicadas and bedbugs. The purpose of our research was to study the species composition of transmitters and the intensity of their flight in North Ossetia. Studying the activity of the winged aphid vector is a prerequisite for the implementation of protective measures against re-infection of the sanitized material with viruses. The most important criteria characterizing aphids in transferring potato viruses during the growing season were as follows: the species composition, the dynamics of the potato planting periods, the timing of the critical threshold with regards to the number of aphids, and the total vector intensity during the growing season. There are very few aphid vectors in the mountain zone of the Republic of North Ossetia, which is at and above an altitude of 1,650 meters above sea level. Therefore, mountain regions of this height are a natural insulator against viral infection. In the foothill zone, the most numerous aphid vectors are bean, buckthorn, and alder buckthorn-willowherb aphids, whose number varies from 35 to 280 individuals per year on a Merike trap. Keywords: potatoes, insect vectors, a Merike trap, mountain zone, spatial isolatio

External cavity diamond Raman laser at 2.52 μm

An external-cavity diamond Raman laser at 2.52 μm, pumped by a home-built Tm:YLF laser, is reported. The maximum output pulse energy is 1.1 mJ for 4.74 mJ incidence yielding a total conversion efficiency of 23%.The slope efficiency is 49% and the Raman pulse duration is between 23-26 ns for 42 ns pump pulse duration

Fertility of Leached Chernozem and Productivity of Winter Wheat Depending on Fertilizers in a Forest-steppe Zone

The study revealed optimum doses, NPK combinations, terms and methods of fertilizer application, which provides for highly efficient use of nutrients thus maintaining the fertility of soils, high efficiency and high quality of winter wheat grains. The application of some mineral fertilizers was followed by some decrease (trend) of humus content in relation to control samples. The option manure+NPK was characterized by relative stabilization of humus condition of soil, and concerning the average humus content this option exceeded the control one by 0.32 %. Fertilizers clearly improved the nutrient status of leached chernozem under winter wheat enriching its 0–40 cm layer with mobile nitrogen (NН4+ and NO3−), phosphorus and potassium respectively by 6.0–9.2; 3.2–9.4; 9.3–36.7 and 21.5–32.8 mg/kg of soil on average per vegetation. Options with high doses of mineral fertilizers were characterized by the largest content. The application of fertilizers under winter wheat in N50−150P40−120K40−120 doses increased grain yield from 0.22 to 2.32 t/ha (6.9–72.5 %). The estimated option was the best

Phytoinsecticides to Fight Against Colorado Beetle

Nowadays researchers are focused on biological farming. In modern environmental conditions the reduction of the chemical load on the environment is a current issue. In the article the following plants are used as pest management, especially, with Colorado potato beetle: jimson weed, white hellebore, Camelina. They contain a lot of alkaloids and essential oils that inhibit weeds and frightening off potato pests. The use of such agricultural practices on large areas reduces the cost of chemical means of pest control and improves product quality while maintaining the environment

Potato breeding at Gorsk State Agrarian University

The article highlights issues of breeding work at Gorsk State Agrarian University in 2022. Obtaining productive potato varieties that resistant to various pathogens in the conditions of the mountain foothills of the North Caucasus is the goal of the research. The main objectives are to identify dominant characteristics of the studied varieties for their further use as parent forms, to evaluate hybrid offspring based on the main economically valuable characteristics, to select the most valuable genotypes according to variety models for a given region (6). In the collection nursery parental pairs were identified for further use in the breeding process. The studies were carried out on mountain meadow and leached chernozems of the North Ossetia-Alania. The experiments were carried out according to the methods of selection and seed production developed by VIR, VIZR and VNIKH named after. A.G. Lorja. In various nurseries of the breeding process promising hybrid offspring were identified. In the maternal nursery more than 6.5 thousand seeds were obtained as a result of backcrossings in 7 combinations. In the nursery of first-year seedlings 15% of genotypes were rejected according to morphological characteristics. During harvesting 42% of genotypes were rejected and the selection rate was 58%. In the nursery of second-year seedlings the average selection among planted genotypes averaged 79.2%. In the nursery of seedlings of the third year hybrids of four combinations were tested, 3 of which were rejected, only 133 combinations of offspring were obtained, and the selection rate was 11.1%. The isolated hybrid progenies, namely, 12.64/368, 12.40/1 and 12.64/394 with a yield of 51.7 t/ha, 48.7 t/ha and 48.1 t/ha, and marketability of 82.3%, 80.0% and 84 .0% will accordingly be transferred to a breeding nursery for further research and submission to the State Crop Testing Site of the Russian Federation

Controlled potato breeding zoned for the conditions of the Central Caucasus

Introduction. Potato is one of the crops most susceptible to diseases. In the Russian Federation, the annual potato yield loss due to disease is 20-25 %. Stems and tubers serve as a substrate for the development of microorganisms, fungi and pathogenic bacteria. The risk of potato disease is possible both during the growing period and during storage.   The goal of the research is to create competitive varieties with high economically valuable traits, zoned for the North Caucasus region.   The methods. All records and observations were carried out according to the methods of the selection process.   As a result of the research, more than 200 varieties of various originators were used in the collection nursery of the Gorsk State Agrarian University. The work has been carried out in various directions for 23 years, including resistance to diseases and pests. Five varieties with high economic and biological indicators and productivity have been bred. As a result of the research, it has been found that hybrid offsprings of the 35th, 26th and 30th combinations have demonstrated high resistance of tops and tubers to famine fungus. 84.7 % of hybrid populations have demonstrated resistance to viral diseases. At present, the following hybrids have provided a competitive yield: 11.35/12 - 45.2 t/ha, 11.26/816 - 44.3 t/ha, 11.26/33 - 48 t/ha, 11.26/35 - 40.0 t/ha. The following hybrids have shown the highest stable quality indicators for starch and dry matter content: 11.35/12, 11.26/816, 11.26/594 - 16.2-16.8%, 22.2-22.8%, and their maximum accumulation has been noted in the hybrids of the 7th combination - from 17.4 to 24.4 % and from 23.3 to 30.5 %, respectively.   Conclusions. Thus, much attention has been paid to breeding in the direction of resistance of various potato varieties to a number of diseases

Spectroscopic and lasing characteristics of samarium-doped glass fibre

The fluorescence spectra of trivalent samarium doped glass fibres are described. In silica glass Sm3+ has a narrow fluorescence of 2.2 nm f.w.h.m. at a wavelength of 650 nm The influence of fluorescence line narrowing and large external electric fields on this line is reported. Visible laser emission is obtained at this wavelength when the fibre is pumped in a Fabry Perot cavity. The performance of the laser in continuous, Q-switched and self mode-locked operation is described. The basic theory of self-mode-locking is presented