Commercial Heads Research Articles

Application of microalgae in cauliflower fertilisation

In a circular bioeconomy, balancing inorganic fertilisers and microalgae supplementation is important for ensuring sustainable agriculture. This study aimed to evaluate the fertilising effects of live microalgae (mostly Chlorella vulgaris and a mixture of Chlorophyceae and Trebouxiophyceae) on cauliflower (Brassica oleracea L. subsp. botrytis) plant morphology, yield, and quality of cauliflower heads. Microalgae fertilisation effects were analysed by employing an experimental factorial design with two factors: inorganic fertiliser and microalgae, each at high and low dosage levels, and the results revealed higher plant height, wider stem diameter, and lower stem slenderness in high-dose combinations than those in other combinations. In addition, an increase in nitrate, calcium, potassium, and sodium content was observed in the sap of cauliflower leaves in high-dose combinations compared to those in low-dose combinations. The high-dose combination also increased the yield, number of commercial heads, weight of the heads, and number of curds per head of cauliflower. Overall, the study demonstrates that increasing the dose of inorganic fertilisers and microalgae significantly increases nutrient concentration in the sap, which translates into a larger plant, an increase in the number of leaves and yield, and an improvement in the quality of cauliflower heads. These findings underscore the necessity for further research to ascertain the optimal combination of inorganic fertilisers and microalgae to maximise crop yield and cauliflower head quality.

ВЫНОС ЭЛЕМЕНТОВ ПИТАНИЯ ОВОЩНЫМИ КУЛЬТУРАМИ ПРИ КАПЕЛЬНОМ ОРОШЕНИИ В САРАТОВСКОМ ПРАВОБЕРЕЖЬЕ

To successfully solve the problem of import substitution of vegetable products, it is necessary to significantly increase the yield of vegetable crops in Russia. A large role in increasing yields belongs to the correct fertilizer system, the development of which requires knowledge of the removal of nutrients and the influence of biotic and abiotic factors on it. Taking into account that for vegetable crops grown in the steppe zone of the Saratov Right Bank, data on the removal of nutrients were not determined, the purpose of the research was to experimentally determine the removal of the main vegetable crops – tomatoes, late cabbage and eggplant, and to study the effect on this indicator and yield of drip irrigation regimes and norms of mineral fertilizers on the chernozems of the southern region. Experimental methods were used in the work – field and laboratory experiments to study the yield and removal of nutrients by the studied vegetable crops under different modes of water and mineral nutrition with drip irrigation, and statistical methods – dispersion and correlation analysis. The article presents the results of research on the influence of irrigation regimes and fertilizer rates on the removal of nutrients and the productivity of varieties of valuable vegetable crops during drip irrigation on the chernozem of the southern Saratov Right Bank; The coefficients of the removal of batteries per 1 ton of the main and by-products of tomatoes, late white cabbage and eggplant at different agrophones were determined. The dependences of the removal of nutrition elements of tomato varieties on the irrigation norm and the total dose of fertilizers, the removal of NPK eggplant from the doses of mineral fertilizers are established. It is proved that all the studied crops formed the highest yield at the calculated dose for an increased yield level, while their reaction to the improvement of the water regime was different. The highest yield of late white cabbage of the Amager variety 611 85.59 t /ha of commercial heads and eggplant fruits of the Black Handsome variety 88.69 t / ha was obtained under irrigation regime of 90% NV, and tomatoes – at 80% NV

Sheep and goat breeding

The beginnings of sheep and goat production go back to the dawn of human civilization. In the geographical areas where the first human civilizations began to develop, the domestication of sheep from wild animals that lived there began. The first domesticated animals did not differ much from their original forms and changes in morphological and production characteristics followed later during the development of sheep and goat production. Significant contributions to the development of these branches of animal husbandry were made by ancient world cultures such as Egyptian, Greek, and Roman. Changes in production were formed specifically to meet the needs of specific products such as wool, meat and milk. In this process, significant morphological modifications have occurred, such as changes in hair in wool in sheep, changes in the skin, deposition of adipose tissue, horn lessness and so on. In addition to this, there was a differentiation of breeds in accordance with the production goals that were primary, so that meat, dairy and wool production types were singled out. Along with the processes of differentiation of production types, a large number of breeds have developed, mainly according to geographical distribution. New breeds have characteristics that have been developed under the influence of man and are based on specialized or combined production of milk, meat and wool. In Europe, sheep production accounts for a significant share of total livestock production, especially in countries where cattle production has been reduced due to various geographical factors. In sheep and goat production in Europe, the leading countries are the Mediterranean countries, which have developed traditional sheep and goat products of high economic value. In Bosnia and Herzegovina, sheep and goat production are not at a satisfactory level. It is mostly about extensive sheep and goat farming without organized and systemic solutions to the problems in this production. The breed composition in Bosnia and Herzegovina is based mostly on strains of the autochthonous pramenka breed without organized selection work. Typically, sheep and goat products should be based on different technological processes such as the production of meat, milk, wool and combined output. The breeding system itself is based on the breeding of purebred breeding heads and the breeding of commercial heads for production and the market. An important element of breeding is reproduction, since these are seasonal animals whose mating season is in the fall. In order to increase the productivity and accumulativeness of these branches of livestock production, the method of estrus synchronization using various hormonal preparations is applied. Defining breeding goals is the main starting point when it comes to any livestock production, so this is the case with sheep and goat breeding. Animal selection is carried out in accordance with breeding goals. In addition to economic importance, sheep and goat production play an important role as an ecological factor in the use, preservation and conservation of pastures.

About the compliance of white cabbage varieties and hybrids with the real demand of population

Relevance. The actual demand for cabbage is based on the demographic composition of the Russian population. Based on this provision, the weight size of marketable, in particular, midripening cabbage, in the range from 1 to 3 kg, is justified. However, until now, domestic breeding firms are focused on the creation of hybrids with increased yields, not taking into account the real demand of the population.Materials and methods. The studies were carried out on mid-season hybrids of white cabbage of the fifth maturation group SB-3 F1 and Kuizor F1 in vegetable-growing farms of the NonChernozem zone of the Russian Federation typical for that time: "Bykovo" and "Agrofirma" Podmoskovnoe".Results. Studies on the mid-season hybrid SB-3 F1 showed that the share of commercial heads of cabbage ranged from 32.9-44.1%, reaching 73.3% in only one technological variant. The share of commercial heads in hybrids of foreign selection Kuizor F1 was 97%. A radical way to meet the requirements of the population is the creation of mid-season hybrids with different dynamics of growth of the marketable mass of heads of cabbage and, accordingly, with different lengths of the growing season. This is necessary to ensure the receipt and sale of marketable products – biologically ripe heads of cabbage weighing 1-3 kg within 2-3 months of the summer-autumn period. At the same time, obtaining such heads of cabbage should be ensured by the genetic potential of hybrids.

Methodology for assessing the executives’ performance ensuring the healthcare companies sustainable development

The article presents the methodological tools for the evaluation the executives’ performance ensuring the companies’ sustainable development: the essence and the quantitative assessment concept of the organizational leaders’ performance; the performance conceptual apparatus features and assessment. The performance evaluation concept is proposed on the basis of various management theories combining, taking into account the stage of the organization’s life cycle. The performance evaluation stages are shown in five blocks. An indicative approach is used to assess performance, it is quantified as an indicator which integrates particular performance indicators that characterize the goals achievement for the main managing parameters (finance, patient relations, business processes, staff training and growth, and corporate management). The indicative approach features to the integrated commercial organization heads performance assessment are shown using commercial healthcare company as an example. The lifecycle stage is reflected by modification the number, composition, weights and standards value of assessment indicators. The necessity of BSC building is justified as a reflection of the social orientation and the profit generation sustainable development for the medical organization.

Key determinants of wind energy growth in India: Analysis of policy and non-policy factors

Wind energy has been considered as an important resource to meet the energy needs of India in a sustainable manner, with over 30 GW installed capacity as on December 2017. However, the wind sector has witnessed a temporal and spatial asymmetrical growth in India over the last decade, attributed to policy inconsistency. We analyzed wind growth in six resource rich states of India from 2003 to 2016, using panel data regression, considering 16 exploratory variables categorized under policy, geographic, economic, social, technical and commercial heads. Contrary to expectation, both policy variables FIT and RPO came out as insignificant factors. The existing wind capacity and its share in the total generation capacity came out as significant drivers. Commercial factors like industrial tariff and utility's performance got reflected as other determinants. Stark variations were observed in state-wise analysis, with wind growth in some states responding to infrastructure factors like road network. Scaling up wind deployment in resource rich Indian states would require policy instruments contextualized to their economic profile, energy resources and power market.

Facial preservation following extreme mummification: Shrunken heads

Shrunken heads are a mummification phenomenon unique to South America. Ceremonial tsantsa are ritually reduced heads from enemy victims of the Shuar, Achuar, Awajún (Aguaruna), Wampís (Huambisa), and Candoshi-Shapra cultures. Commercial shrunken heads are comparatively modern and fraudulently produced for the curio-market, often using stolen bodies from hospital mortuaries and graves. To achieve shrinkage and desiccation, heads undergo skinning, simmering (in water) and drying. Considering the intensive treatments applied, this research aims to identify how the facial structure can alter and impact identification using post-mortem depiction.Sixty-five human shrunken heads were assessed: 6 ceremonial, 36 commercial, and 23 ambiguous. Investigations included manual inspection, multi-detector computerised tomography, infrared reflectography, ultraviolet fluorescence and microscopic hair analysis.The mummification process disfigures the outer face, cheeks, nasal root and bridge form, including brow ridge, eyes, ears, mouth, and nose projection. Melanin depletion, epidermal degeneration, and any applied staining changes the natural skin complexion. Papillary and reticular dermis separation is possible. Normal hair structure (cuticle, cortex, medulla) is retained. Hair appears longer (unless cut) and more profuse following shrinkage. Significant features retained include skin defects, facial creases, hairlines and earlobe form. Hair conditions that only affect living scalps are preserved (e.g. nits, hair casts). Ear and nose cartilage helps to retain some morphological information. Commercial heads appear less distorted than ceremonial tsantsa, often presenting a definable eyebrow shape, vermillion lip shape, lip thickness (if mouth is open), philtrum form, and palpebral slit angle. Facial identification capabilities are considered limited, and only perceived possible for commercial heads.

A morphometric investigation into shrunken heads

Abstract This is a first time morphometric investigation into 65 shrunken heads from South America, comprising 6 ceremonial tsantsa, 36 commercial heads, and 23 ambiguous heads. Ceremonial tsantsa are heads ritually reduced by the Shuar, Achuar, Awajun (Aguaruna), Wampis (Huambisa) and Candoshi-Shapra, following a long-standing war trophy tradition. Commercial heads were produced solely for trade since c.1872. Ambiguous classified heads resemble ceremonial tsantsa, but demonstrate minor questionable anomalies in their design. Thirty-two dimensions were reliably collected utilizing a sliding caliper, soft measuring tape and multi-detection computerized tomography (MDCT). Box and whisker charts plot the range in dimensions identified for each shrunken head category, including collection total. Ceremonial tsantsa were most consistent in scale. Sample sizes were small, but the long-established and religious nature of applied techniques likely influenced this result. Ambiguous heads were closely affined, but wider ranging in scale to ceremonial tsantsa. Commercial heads, produced using irregular methods, demonstrated the strongest variation in scale. They were generally larger, but presented both the very largest and smallest heads in the collection. The largest heads (with c.7–8 mm visible tissue depth) were marked with mould, suggesting improper processing and desiccation; hair analysis confirmed the smallest (c.1.2–1.7 mm visible tissue depth) were of juveniles. Visible tissue depths, taken from skin lining the neck/head opening, was typically c.3–4 mm. MDCT analysis otherwise identified a tissue depth variance of 1.95–3.67 mm minimum (common in upper face and inferior to chin regions) and 3.49–10.09 mm maximum (at vertex). Ceremonial and ambiguous heads often presented moderately thicker, heavier skins to commercial heads, with evident papillary and reticular layer separation of the dermis, from an imbalanced heat application and pronounced manual manipulation during desiccation. To advance research findings, a greater sample size of ceremonial tsantsa is required to ideally identify morphometric parameters that definitively differentiate ceremonial and commercial heads.

Micromagnetic Model Analysis of Various Spin-Torque Oscillators With Write Head for Microwave-Assisted Magnetic Recording

A micromagnetic model analysis was carried out considering two types of write heads and three types of spin-torque oscillators (STOs). For write heads, we considered a small-sized head to reduce calculation time and a large-sized head with dimensions close to commercial heads. For STOs, we used a double-layered STO with reflection spin torque, a double-layered STO with transmission spin torque, and a tri-layered STO with two spin injection layers. We also carried out micromagnetic simulations of the STOs without the write heads (isolated STO) to compare the oscillation states. It was found that, compared with isolated STOs in a uniform applied field, a larger applied field was necessary for STOs integrated into a write head. This result shows that the write head should be designed to generate a large, well-shaped gap field to ensure stable STO oscillation.

Peculiarities of forming quality parameters of commercial products of cutting lettuce (<i>Lactuca sativa var. capitata L.</i>) depending on the method of cultivation

Purpose. To investigate features of commercial head quality formation in varieties of cutting lettuce (Lactuca sativa var. capitata L.) for different growing methods. To study the influence of growing methods for cutting lettuce plants on the weight of commercial heads, indices of yield and quality of freshly harvested products.Methods. Field study, laboratory testing and statistical evaluation.Results. The results of studying peculiarities of head formation in such cutting lettuce varieties as ‘Godar’ (control), ‘Smuhlianka’, ‘Olzhych’ and ‘Dyvohrai’ were shown. Based on the results of phenological observations, the duration of interstage periods of growth and development of cutting lettuce plants was determined for the different growing methods. The model of cutting lettuce of capitata variety for different growing methods was presented in terms of biochemical parameters (content of dry matter, vitamin C, nitrates, amount of sugars). The influence of growing methods for cutting lettuce plants on the commercial head weight, indices of yield and quality of freshly harvested products was studied. Obtained results confirmed that in early ripening varie­ti­es the heads were smaller (150 g) and not dense, in late ripening varieties they were large and dense, weight was 150–500 g. Freshly harvested commercial products of head lettuce in case of seedling cultivation was characterized by a slight increase in dry matter content by 0.15–0.29%. The corresponding pattern was observed for the total sugar content. Its amount was slightly higher: 1.3–1.9% in case of direct sowing and 1.6–1.9% – for seedlings cultivation. The content of ascorbic acid (vitamin C, mg/100 g) was the highest in the ‘Dyvohrai’ variety despite of the method of growing. The largest quantity of nitrates in lettuce heads was in the inner stem (480 mg/kg), while in the middle of the head it was reduced to 110 mg/kg.Conclusions. Freshly harvested heads of cutting lettuce were analyzed for the content of such basic biochemical indices as dry matter, vitamin C, protein, nitrates, amount of sugars. Biochemical characteristics of freshly harvested products of heading lettuce in case of direct sowing and non-seedling methods of growing were within the error being almost identical with minor deviations. According to the study results, a typical model of capitate lettuce variety was designed which will have practical application in qualification examination of plant varieties.

Sprout density for the production of organic mini-cabbage from mother plant regrowth

ABSTRACT: The method of producing organic mini-cabbages from regrowth of mother-plant was initiated at the Unidade de Referência em Agroecologia of the Incaper in 2013, possibly acting as an efficient alternative for the obtainment of cabbages with a more adequate average weight for the desires of the modern consumer. The aim of this study was to define sprout density in the mother plant, which allows better productivity and commercial standards for organic mini-cabbages. The experiment was developed during the period from September to November 2015, using the F1 Shinsei hybrid, in a design with randomized blocks, with five replications. Sprout density was determined following thinning, constituting the following treatments: two, three, four, five and six sprouts per plant. Best management of sprouts was the technique with four sprouts per plant, since it allowed greater productivity (52,997kg ha-1) and a greater number of commercial heads, together with a commercial standard of heads with average weight (414g) and median diameter (8.8cm) adequate for the standards demanded by the consumer.

Recently identified features that help to distinguish ceremonial tsantsa from commercial shrunken heads

This is an anthropological investigation into a collection of 65 shrunken human heads, to determine if new characteristics can be identified to facilitate the differentiation between ceremonial tsantsa and commercial shrunken heads. Ceremonial tsantsa refers to shrunken heads mummified as war trophies within the ancient traditions and rituals of the Amazonian Shuar, Achuar, Awajun/Aguaruna, Wampis/Huambisa and Candoshi-Shapra (SAAWC). Commercial shrunken heads are comparatively modern objects constructed specifically for the collector market of the past. Low earning individuals in South and Middle America, outwith the SAAWC culture, who had access to corpses and appropriate medical or taxidermy provisions, produced these for trade purposes. These heads were made in abundance and do not present the same historical value or heritage as ceremonial tsantsa. The relevance of an accurate provenance for heads may directly impact museums, with regard to identifying the authenticity of a specimen and how they should handle any potential requests to return such artefacts to their cultural homes. Complying with current anthropological standards, a total of 6 ceremonial tsantsa and 36 commercial heads were identified. Greater confidence is prescribed to the assignment of commercial heads as their morphological appearance is at odds with the highly standardised presentation of ceremonial tsantsa. Many indicated that the processor had access to modern resources such as gloves and fine suturing equipment, which were not typically available to the SAAWC. Since traders sometimes closely replicating ceremonial tsantsa when shrinking and decorating heads for trade, limited certainty can be prescribed to this category. Minor deviations in ceremonial design resulted in 23 heads being defined as ambiguous in origin. Each head was examined by manual inspection, infrared reflectography (IRR), CT and microscopic hair analysis, with ten new differentiating characteristics identified. © 2016.

Probabilities of Transition Jitter at Different Off-Track Positions

Current typical perpendicular commercial media has grain size of around 8 nm, which the size has remained more or less the same since its introduction. Typical bit lengths for the media can go as low as 15-20 nm. Transition jitter, which is one type of media noise, tends to occur at regions where magnetic transitions could be found. Such noise could affect the storage and readability of the data, especially as more accuracy is demanded when hard disk industries push for higher and higher densities. This work describes the methodology of using averaging methods to measure the writer footprints jitter profiles which are recorded at different writing currents on a Spinstand. Two different commercial heads have been used for the evaluation. Multiple down-track footprint averaging and least square fitting of the individual transition footprint data against the noise-free footprint are used to retrieve the jitter profiles of the writers at different writing conditions. The statistical jitter profiles are then used to plot various cross-tracks and regionalized jitter distribution and probability plots. From the plots, it is quite conclusive to determine that writer A at 50 mA especially at the track center (TC) has the minimal and thus best jitter profile amongst the other writing conditions and heads used.

Seleção de genótipos de alface para cultivo protegido: divergência genética e importância de caracteres

Os objetivos deste trabalho foram selecionar genótipos de alface com potencial para cultivo em ambiente protegido; selecionar genótipos divergentes geneticamente para integrar programas de melhoramento; comparar técnicas multivariadas a fim de se ter uma interpretação mais precisa dos resultados; verificar a relevância dos caracteres avaliados para a divergência genética; e determinar os caracteres mais importantes na avaliação de genótipos de alface. Utilizou-se o delineamento em blocos casualizados, com 15 genótipos, quatro repetições e 15 plantas por parcela. O experimento foi conduzido em ambiente protegido e avaliou-se a altura das plantas, diâmetro da cabeça, circunferência da cabeça, matéria fresca da parte aérea, matéria fresca comercial da parte aérea, matéria fresca da raiz, matéria seca comercial da parte aérea, matéria seca da raiz e número de folhas comerciais. Os genótipos foram classificados em quatro grupos pelo método Tocher. Foram indicados para uso em cultivo protegido e em programas de melhoramento para obtenção de cultivares adaptadas a essas condições, as cultivares 'Regina 500'e 'Vitória de S. Antão' (grupo I), 'Black Seed Simpson' e 'Lívia' (grupo II), 'Branca Boston' (grupo III) e 'Romana Balão' (grupo IV). Embora a contribuição relativa da circunferência para a divergência seja apenas 0,50%, todas as características avaliadas foram importantes no estudo da divergência genética. De acordo com o estudo da correlação genotípica, a avaliação da característica massa fresca da parte aérea pode substituir a avaliação das características massa fresca e massa seca comercial da parte aérea em um processo de seleção, reduzindo tempo e custo em um programa de melhoramento.

Writing Process Induced Media Noise Measurement

Writing processes can cause extra medium noise, which is the dominant noise in the perpendicular recording system. This work describes the methodology of using averaging methods to measure the writer footprints and its noise profiles, which are recorded at different writing currents on a Spin-stand. Two different commercial heads have been used for the evaluation. The test is performed on a 2.5 inch commercial disc at the middle diameter (MD) location, rotating at 5400 RPM spindle speed, and at 0 skew angle. The center track is DC erased over an AC erased background and then recorded with a repetitive footprint data pattern and an alignment data pattern. Multiple revolution averaging and down track footprint averaging are used to retrieve the noise free footprint profile of the writer. Using the noise free footprint profile, the statistical characteristics of noise can be derived from the individual noisy footprint which shows the media noise characteristics induced by writing process. Using footprint and noise profile data, signal to noise ratio (SNR) for regions near the trailing edge of the writer profile are calculated and suggests that the ideal writing condition for writer A and B to be 55 and 25 mA respectively.

Surface Topology of Advanced Alumina/Zirconia Composite Femoral Head as Compared with Commercial Femoral Heads Made of Monolithic Zirconia

Atomic force microscopy (AFM) has been systematically used to image the surface of a femoral head made of alumina/zirconia composite (henceforth referred to as zirconia-toughened alumina, ZTA), in comparison with two types of commercially available femoral heads made of monolithic zirconia. AFM experiments were conducted before and after in vitro exposure in water moist environment. All materials contained zirconia partly stabilized with yttria. AFM observations were performed on wide areas of several heads of each type (i.e., in the order of several tens of μm2), in order to ensure statistical reliability in the topologic measurements. Tetragonal-to-monoclinic phase transformation, which was quantitatively characterized by confocal Raman spectroscopy, showed significant difference among the investigated samples. Such differences were similarly found with respect to both roughness and time needed for topologic changes to occur. Variation of topologic statistic parameters, such as skewness and kurtosis of surface height histograms, confirmed the main impact of zirconia grain size on the environmental stability of the head surface, the finer the grain size the higher the stability.

EFICIÊNCIA DE INSETICIDAS PARA O CONTROLE DE Plutella xylostella (LEPIDOPTERA: PLUTELLIDAE) NA CULTURA DO REPOLHO (Brassica oleracea var. capitata)

The research was carried out in an area under continuous cabbage cropping (Brassica oleracea var. capitata) in Goianapolis, Goias State, Brazil, from September to November 1996. The aim was to compare insecticides for diamondback moth (Plutella xylostella) control. The experimental design was randomized blocks with eight treatments and four replications. The treatments were teflubenzuron in the doses of 25 mL, 30 mL and 40 mL of commercial product (c.p.) / 100 L of water; chlorfenapyr in the doses of 30 mL, 50 mL and 100 mL of c.p./ 100 L of water; deltamethrin in the dose of 30 mL of c.p. / 100 L of water; and control. Treatments were applied weekly after transplanting. Evaluations were made at harvesting, counting the number of holes caused by moth in five randomly chosen commercial cabbage heads per plot. The insecticides teflubenzuron and chlorfenapyr were more efficient than deltamethrin in the control of moth P. xylostella.

Tunneling Magnetoresistive Heads for Magnetic Data Storage

Spintronics is emerging to be a new form of nanotechnologies, which utilizes not only the charge but also spin degree of freedom of electrons. Spin-dependent tunneling transport is one of the many kinds of physical phenomena involving spintronics, which has already found industrial applications. In this paper, we first provide a brief review on the basic physics and materials for magnetic tunnel junctions, followed more importantly by a detailed coverage on the application of magnetic tunneling devices in magnetic data storage. The use of tunneling magnetoresistive reading heads has helped to maintain a fast growth of areal density, which is one of the key advantages of hard disk drives as compared to solid-state memories. This review is focused on the first commercial tunneling magnetoresistive heads in the industry at an areal density of 80 approximately 100 Gbit/in2 for both laptop and desktop Seagate hard disk drive products using longitudinal media. The first generation tunneling magnetoresistive products utilized a bottom stack of tunnel junctions and an abutted hard bias design. The output signal amplitude of these heads was 3 times larger than that of comparable giant magnetoresistive devices, resulting in a 0.6 decade bit error rate gain over the latter. This has enabled high component and drive yields. Due to the improved thermal dissipation of vertical geometry, the tunneling magnetoresistive head runs cooler with a better lifetime performance, and has demonstrated similar electrical-static-discharge robustness as the giant magnetoresistive devices. It has also demonstrated equivalent or better process and wafer yields compared to the latter. The tunneling magnetoresistive heads are proven to be a mature and capable reader technology. Using the same head design in conjunction with perpendicular recording media, an areal density of 274 Gbit/in2 has been demonstrated, and advanced tunneling magnetoresistive heads can reach 311 Gbit/in2. Today, the tunneling magnetoresistive heads have become a mainstream technology for the hard disk industry and will still be a technology of choice for future hard disk products.

Inseticidas para o controle da traça-das-crucíferas e impactos sobre a população natural de parasitóides

A traça-das-crucíferas (TDC) Plutella xylostella (Lepidoptera: Yponomeutidae) é a principal praga da cultura do repolho e seu controle é feito através de inseticidas, com possíveis efeitos adversos na população natural dos seus parasitóides. Nos últimos anos, novos ingredientes ativos foram colocados no mercado, tornando necessária a avaliação da eficiência destes produtos e o impacto na população de parasitóides. Com este objetivo, foi instalado um experimento, de junho a outubro de 2001, na área experimental da Embrapa Hortaliças, com a cultivar Kenzan. Foram utilizados os produtos Spinosad (38,4 g i.a./ha), Thiacloprid (96 g i.a./ha), Indoxacarb (24 g i.a./ha), Bacillus thuringiensis var. kurstaki (16,8 g i.a./ha), uma nova cepa (S764, concentração de esporos 4 x 10 E 9) de B. thuringiensis (168 g i.a./ha), disponibilizada para teste pela Embrapa Recursos Genéticos e Biotecnologia e uma testemunha, sem pulverização. As pulverizações, num total de oito, foram semanais, iniciando-se a partir da formação das cabeças de repolho, quatro semanas após o transplante. Foram efetuadas amostragens semanais em cinco plantas por parcela, contando-se o número de furos e larvas nas quatro folhas centrais da cabeça do repolho. Avaliou-se também o número de larvas na parte externa da cabeça do repolho. A cada 15 dias foram efetuadas coletas de larvas (folhas centrais e externas), que eram levadas ao laboratório para avaliação de parasitismo. Por ocasião da colheita, as cabeças foram avaliadas quanto ao valor comercial, através de notas e porcentagem de cabeças comerciais, além da contagem do número de furos, larvas na cabeça e larvas na planta toda. Os produtos Spinosad, Indoxacarb e B. thuringiensis var. kurstaki foram os mais eficientes para o controle de P. xylostella e não diferiram entre si para os parâmetros avaliados. A utilização desses produtos propiciou a produção de cabeças de repolho com alto padrão comercial. Os produtos Thiacloprid e a cepa de B. thuringiensis S764 (Embrapa Recursos Genéticos e Biotecnologia) não foram eficientes. O B. thuringiensis var. kurstaki conciliou eficiência de controle com baixo impacto na população de parasitóides. O produto Spinosad apresentou impacto na população de parasitóides, quando foram amostradas larvas de P. xylostella da cabeça do repolho. As espécies de parasitóides coletadas com maior freqüência foram Diadegma leontiniae; Apanteles sp.; Actia sp. e Oomyzus sokolowskii.

Avaliação de larvicidas de origem microbiana no controle da traça-das-crucíferas em couve-flor

Dois inseticidas biológicos à base de Bacillus thuringiensis subspécies kurstaki (Btk) e aizawai (Bta) e um inseticida não sistêmico de origem biológica, à base de spinosad, foram avaliados em campo contra a traça-das-crucíferas, Plutella xylostella (L.)(Lep.: Plutellidae), em cultivo de couve-flor. O experimento foi realizado em Brazlândia, DF, em uma área de produção regular de hortaliças. A lavoura foi conduzida segundo manejo indicado para a região, sem qualquer intervenção que não o controle da praga. O experimento foi realizado no período de julho a setembro de 2002. O delineamento foi de blocos ao acaso, com quatro tratamentos e quatro repetições. Os produtos foram aplicados em função da média do número de furos produzidos pela praga, presentes nas quatro folhas centrais das plantas, sendo os diferentes tratamentos avaliados semanalmente. Quando a média do número de furos atingia valor igual ou superior a seis, os produtos eram aplicados. Adotando-se este procedimento, aplicou-se três vezes o inseticida spinosad e seis vezes os inseticidas Btk e Bta. Os três tratamentos com inseticidas não diferiram entre si, mas diferiram significativamente da testemunha quanto à produção. As áreas tratadas com Btk produziram 78,1% de cabeças comercializáveis, as tratadas com Bta 76,5% e as tratadas com spinosad 75,5%. No controle houve perda de 34,4% da produção. A utilização dos produtos aumentou a receita da cultura da couve-flor em relação à testemunha, nos valores de R$ 2.505,19 com o Btk, R$ 1.954,55 com o Bta e R$ 1.891,65 com spinosad.