Creating competitive galega and bromus cenoses

Field experiments (2001–2005) were carried out to create optimal schemes for sowing mixtures of perennial grasses in the forest-steppe of Western Siberia. Objects of research were Krasnoobsky oats, Eastern galega Gorno-Altayskaya 87, awnless brome Antey. The soil of the plots was medium thick, medium loamy leached chernozem. The experiment was carried out in two layouts spread in time and in space. Grasses were sown under the cover of Krasnoobsky oats. Awnless brome was sown across galega in the first ten days of May. Seeding rate of awnless brome was 3.0; 4.5 and 6.0 million germinating seeds per hectare. Recordings of yield were made according to standard methods. The highest yield of galega dry mass was achieved when it was sown in rows with awnless brome planted with inter-row spacing of 15 cm (it was higher than with 30 cm inter-row spacing by 1.16 t/ ha and 0.63 t/ha, respectively). In the variant “three rows of galega + a row of awnless brome” (3 : 1), the yield of dry mass of the mixture in two cuttings was higher by 5.7 and 2.1% than when they were sown with every other row skipped. The total yield for two cuttings exceeded single-species crops of galega by 0.48–2.03, and awnless brome by 2.15–2.54 t/ha. A tendency towards a decrease in the yield of dry mass in single-species crops of galega with an increase in row spacing was noted. In mixtures sown at the same time according to the 3 : 1 scheme, the yield of dry mass was 5.14 t/ha in the first mowing and 4.05 t/ha in the second. This is higher than in the mixture sown according to the scheme “a row of galega + a row of awnless brome” (1 : 1) by 2.2–7.6, or 2.2–13.1%. Awnless brome in mixtures is more competitive than galega. An increase in the seeding rate of awnless brome from 3.0 to 6.0 million germinating seeds/ha in the herbage of galega increased the yield by 0.9–1.37 t/ha. The yield of dry mass of mixtures sown at the same time was higher than mixtures with awnless brome planted between rows of galega with spacing of 15 cm by 2%, and with row spacing of 30 cm by 10%.

RENDIMENTO DO PROCESSAMENTO DOS PRODUTOS ORIUNDOS DA FIBRA VEGETAL DA PIAÇAVA (Attalea funifera)

O presente trabalho abordou uma análise integrada do processamento dos Produtos Florestais Não Madeireiros (PFNM) oriundos da fibra vegetal junto aos diversos atores da cadeia produtiva da piaçava da Bahia (Attalea funifera Mart. Arecaceae). Atualmente a renda média do agroextrativista é aproximadamente R$ 600,00/mês no sistema convencional. Neste caso as fibras vegetais são processadas e comercializadas nas formas: bruta, limpa, cortada, fino-média e grosso-média. Para obtenção de uma análise integral da cadeia produtiva, a metodologia empregada consistiu em: ensaios de rendimento em seis sistemas produtivos diferentes e entrevistas com gestores, diálogos com produtores e agroextrativistas tradicionais. Os resultados do processamento da fibra vegetal apontaram que 47,3% de resíduos são descartados, 35,6% são fibras fino-média, 5,3% grosso-média e 17% de “fita” são aproveitadas. Os ganhos do agroextrativista, supondo um cenário em que todas as etapas do processo produtivo de confecção das vassouras de piaçava fossem realizadas, corresponderiam a uma renda mensal líquida de R$ 1.664,63, muito acima da renda média atual.Palavras-chave: fibras naturais; produtos florestais não madeireiros (PFNMs); piaçava da Bahia; agroextrativismo; Mata Atlântica; resíduos florestais. YIELD OF THE PRODUCTS PROCESSING FROM THE VEGETABLE FIBER OF PIASSAVA PALM TREE (Attalea funifera) ABSTRACT: This article point out an integrated analysis of the processing of non-timber forest products (NTFPs) originating from the vegetable fiber with the different actors of the productive chain of the piassava palm tree of Bahia (Attalea funifera Mart. Arecaceae). Currently the average income of the of the agroextractivist is approximately US$ 256,13 per month in the conventional system. In that case, the vegetable fibers are processed and commercialized in the forms: raw fiber, clean fiber, cut fiber, thin-medium fiber and thick-medium fiber. In order to obtain complete analysis of piassava palm tree production chain, the methodology used consisted of: performance tests in six different production systems, the interviews with managers and dialogues with traditional producers and agroextractivists. The results of the processing of the vegetable fiber indicated that 47,3 % of the residues are discarded, 35,6% are thin-medium fibers, 5,3% thick-medium fibers and 17% of “stripes” (by-product) are used. The gains of the agroextractivist, supposing scenario in which all stages of the production process of making the piassava brooms were held, would be followed, might correspond to a monthly net reve nue of US$ 710,59 well above the current average yield.Keywords: natural fibers; Non-timber forest products (NTFPs); Bahia piassava; Atlantic forest; Exploitation of forest residues.

Rooting and growth of root cuttings of two old rose cultivars ‘Harison’s Yellow’ and ‘Poppius’ treated with IBA and biostimulants

Propagation by root cuttings is an easy and low-cost method for plant taxa with an ability to produce rhizomes or suckers. This research examined the possibility of using root/rhizome cuttings in the propagation of two difficult-to-root old rose cultivars, ‘Harison’s Yellow’ and ‘Poppius’. A plant-based preparation (Root Juice), titanium (Tytanit), and IBA (Chryzotop Green 0.25% IBA, Rhizopon AA 020 XX 2.00% IBA) were tested as rooting and growth enhancers for thick, medium, and thin rhizome/root cuttings. Additionally, observations were made to identify the site of the initial root and shoot formation. Shoots appeared before roots, without polarity. The visible swellings differentiating in new root/shoot buds in these two rose cultivars were placed along the rhizome. The primordia of root and shoot buds were situated near the pith rays and the vascular cambial zone. The trial reported here showed significant effects of the thickness of root cuttings and the preparations used in terms of rooting success and growth characteristics. Medium-sized cuttings of rose ‘Harison’s Yellow’ (45.0%), and thin cuttings of ‘Poppius’ (74.3%) achieved the highest rooting percentages. The most effective treatment was with Chryzotop Green, but Root Juice 0.01% and Tytanit 0.04% (‘Poppius’) and 0.02% (both cultivars) also had positive activity. Root Juice and Tytanit can be suggested for rooting cuttings of these roses as eco-friendly preparations.

Radiative Heat Transfer in Participating Medium and Dynamic Region Monte Carlo Method by Region Adaption

A dynamic region Monte Carlo method (DRMC) is proposed to simulate radiative heat transfer in participating medium. The basic principle and solution procedure of this method is described; radiative heat transfer in a two-dimensional rectangular region of absorbing, emitting, and/or scattering gray medium is analyzed. A comparison between DRMC and the traditional Monte Carlo method (TMC) is investigated by analyzing the simulated temperature distribution, the computing time, and the number of the sampling bundles. The investigation results show that, to compare with TMC, the DRMC can obviously reduce the computing time and storage capacity under the same solution precision for radiative transfer in optically thick medium; the DRMC allows bypassing the difficulties encountered by TMC in the limit of optically thick extinction.

X-RAY TRANSMISSION AND REFLECTION THROUGH A COMPTON-THICK MEDIUM VIA MONTE-CARLO SIMULATIONS

The spectral shape of an X-ray source strongly depends on the amount and distribution of the surrounding material. The spectrum of a primary source which is located in an optically thin medium with respect to Compton scattering is mainly modified by photo absorption in the lower energy range and is almost unaltered above ~ 10 keV. This picture changes when the source is obscured by gas exceeding hydrogen column densities of ~ 10²⁴ cm⁻². At this degree of absorption it is likely that photons are scattered at least twice before leaving the medium. The multiple scatterings lead to a lack of photons in the high energy range of the resulting spectrum as well as to an accumulation of photons at moderate energies forming the so-called Compton-bump. The shape of the fluorescent lines also changes since scattered line photons form several Compton-shoulders which are very prominent especially for Compton-thick sources. Using a Monte Carlo method, we demonstrate the importance of Compton scattering for high column densities. For that purpose, we compare our results with existing absorption models that do not consider Compton scattering. These calculations will be implemented in a prospective version of the <em>tbabs</em> absorption model including an analytic evaluation of the strength of the fluorescent lines.