Ефективний розвиток виробничої інфраструктури регіону

The psyllid Diaphorina citri Kuwayama is one of the most important pests of citrus, mainly because it is the vector of the bacterium that causes huanglongbing (HLB) or 'Greening' disease. To study the spatial distribution of nymphs and adults of this pest, an experiment was carried out in two 'Valencia' sweet orange orchards, four and 12 years of age, established in Matão, central area of São Paulo state, Brazil. The following dispersion indices were used to study pest aggregation in the citrus plants: variance/mean relationship (I), index of Morisita (I&#948;), coefficient of Green (Cx), the <img border=0 width=16 height=16 src=../../../../../img/revistas/sa/v67n5/a08form10.gif align=absmiddle>exponent of negative binomial distribution, common k (<img border=0 width=16 height=16 src=../../../../../img/revistas/sa/v67n5/a08form10.gif align=absmiddle>c) and Taylor's Power Law for each sampling. The negative binomial distribution was more representative of the spatial distribution of this psyllid, for both nymphs and adults. For most samplings, psyllid nymphs found in branches and adults caught in traps had an aggregated distribution.O psilídeo Diaphorina citri Kuwayama tornou-se nos últimos anos uma das mais importantes pragas na cultura de citros, principalmente pelos prejuízos causados às plantas por ser o transmissor da bactéria causadora da doença Huanglongbing (HLB) ou 'Greening'. Com a finalidade de estudar a distribuição espacial de ninfas e adultos desta praga, instalaram-se experimentos em duas áreas de citros com histórico de ocorrência de HLB, no município de Matão (região central do Estado de São Paulo), em plantas de laranja 'Valência', com quatro e 12 anos de idade. Para estudo da agregação da população nas plantas, foram utilizados os seguintes índices de dispersão: razão variância/média (I), índice de Morisita (I&#948;), coeficiente de Green (Cx) e expoente <img border=0 width=16 height=16 src=../../../../../img/revistas/sa/v67n5/a08form10.gif align=absmiddle>da distribuição binomial negativa, k comum (<img border=0 width=16 height=16 src=../../../../../img/revistas/sa/v67n5/a08form10.gif align=absmiddle>c) e lei da potência de Taylor para cada amostragem. A distribuição binomial negativa foi o modelo mais adequado para representar a distribuição espacial do psilídeo, tanto para ninfas como para adultos. Na maioria das amostragens, as ninfas encontradas nas brotações e os adultos capturados nas armadilhas apresentaram distribuição agregada

Dépôt de carbures, nitrures et multicouches nanostructurées á base de chrome sous pression atmosphérique par dli-mocvd : nouveaux procédés et potentialités de ces revêtements métallurgiques

Des procédés atmosphériques de dépôt chimique en phase vapeur assisté par l'injection directe liquide (DLI-CVD), prometteurs pour traiter des pièces métalliques au défilé, ont permis l'élaboration à basse température de revêtements métallurgiques performants. Deux précurseurs organométalliques de chrome ont été employés dans différentes atmosphères : Cr (CO)6 pour des dépôts issus du système chimique Cr-O-N-C, et le bisbenzènechrome pour des monocouches de chrome métallique, de carbure (Cr-C) et de nitrure de chrome (CrN), ainsi que des multicouches CrN/Cr-C de bipériode 25 nm. Une approche thermodynamique a permis le calcul d'un nouveau diagramme ternaire Cr-N-C à 527°C, et l'étude de l'impact du solvant sur la nature et la qualité des dépôts en comparaison avec les systèmes chimiques sans solvant. Les propriétés des revêtements (dureté, adhérence, usure, corrosion) sont discutées en relation avec leur microstructure. Les revêtements multicouches nanostructurés CrN/Cr-C présentent des duretés et une tenue à l'usure prometteuses. ABSTRACT : Atmospheric MOCVD processes assisted by Direct Liquid Injection, attractive for on-line strip coating of metal pieces, were developped for the growth of advanced metallurgical coatings. Two chromium metal organic sources have been employed under various ambience : Cr (CO)6 for coatings in the Cr-O-N-C system, and bisbenzenechromium for metal chromium, carbide (Cr-C) and nitride chromium (CrN) monolayer and CrN/Cr-C multilayer coatings with a typical 25 nm biperiod. A thermodynamic approach has permited the calculation of a new ternary phase diagram in the Cr-C-N system and the study of the solvent impact on the nature of the coatings in comparison with chemical systems without solvent. Preliminary mechanical properties from scratch test, nanoindentation and residual stress measurements as well as tribological and corrosion behavior of the mono and multilayer Cr-based coatings are discussed in relation with their microstructure. Nanostructured CrN/Cr-C multilayer coatings exhibit promising hardness and wear resistance

Crotalaria and millet as alternative controls of root-knot nematodes infecting okra

The relationship of crops grown in rotation or in succession has increased every day and the use of antagonistic plants and/or non-host plants is one of the most efficient practices of integrated management of nematodes. This study aimed to evaluate the efficiency of crotalaria (Crotalaria spectabilis Roth) and millet [Pennisetum glaucum (L.) Leeke] ‘ADR 300’ in reducing the population of Meloidogyne incognita and M. javanica and in increasing the productivity of okra [Abelmoschus esculentus (L.) Moench] when cultivated in succession. The experiment was conducted in an area cultivating okra (host culture) in rotation, with a history of severe infestation by phytonematoids. The experimental design involved randomized blocks with six treatments and four replicates, with the following treatments: T1, 15 kg.ha-1 of millet seeds; T2, 30 kg.ha-1 of crotalaria; T3, 10 kg.ha-1 of millet + 20 kg.ha-1 of crotalaria; T4, 20 kg.ha-1 of millet + 6 kg.ha-1  of crotalaria; T5, 6 kg.ha-1 of millet + 36 kg.ha-1 of crotalaria; and T6, control. The nematode populations in the soil and roots were evaluated about 60 d after planting okra, and the yield was evaluated at the end of the crop cycle. Simple treatment with millet or crotalaria reduced the nematode population by 61% and 72%, respectively. The millet-crotalaria intercropping treatments reduced the nematode population by up to 85% compared with the control. In terms of productivity, there was an increase of 787 kg.ha-1 in the millet treatment and 2,109 kg.ha-1 in the intercropping treatments. Both the single cultivation of crotalaria or millet and the consortia of crotalaria and millet were effective in controlling the root-knot nematodes, and increased the productivity of okra

Distribuição espacial e amostragem seqüencial de ninfas e adultos de Diaphorina citri Kuwayama (Hemiptera: Psyllidae) na cultura de citros

O psilídeo Diaphorina citri Kuwayama tornou-se nos últimos anos, uma das mais importantes pragas na cultura de citros, principalmente pelos prejuízos causados às plantas devido à transmissão da bactéria causadora da doença Huanglongbing (HLB) ou Greening. Com a finalidade de estudar a distribuição espacial de ninfas e adultos desta praga, instalou-se um experimento em 2 áreas de citros com histórico de ocorrência de HLB, no município de Matão, região central do Estado de São Paulo, uma com plantas de 4 anos e outra com plantas de 12 anos de idade. Para estudo da agregação da população nas plantas, foram utilizados os seguintes índices de dispersão: razão variância/média (I), índice de Morisita (Id), coeficiente de Green (Cx) e expoente k da distribuição binomial negativa para cada amostragem. A distribuição binomial negativa foi o modelo mais adequado para representar a distribuição espacial do psilídeo na cultura de citros, tanto para ninfas como para adultos. Através da análise destes índices, verificou-se que, na maioria das amostragens, as ninfas encontradas nas brotações e os adultos capturados nas armadilhas apresentaram distribuição agregada. Foram desenvolvidos planos de amostragem seqüencial para ninfas e adultos em região com e sem HLB, e os números máximos de amostras esperados para se tomar a decisão foram de 264 e 83 para ninfas, em regiões com e sem a doença, e de 184 e 150 amostras para adultos, em regiões com e sem a doença.The psyllid Diaphorina citri Kuwayama is one of the most important pests of citrus, mostly because of plant damage due to transmission of the bacterium that causes Huanglongbing (HLB) or Greening disease. The experiment was carried out in 2 sweet orange orchards with previous HLB occurrence in Matão (central region of the State of São Paulo, Brazil), in plants with 4 and 12 years of age, in order to study the spatial distribution of nymphs and adults of this pest. The following dispersion indices were used to study pest aggregation in the citrus plants: variance/mean relationship (I), index of Morisita (Id), coefficient of Green (Cx), and the k exponent of negative binomial distribution for each sampling. The negative binomial distribution was the most representative spatial distribution of this psyllid in citrus, for both nymphs and adults. The analysis of these indices showed that, for most samplings, psyllid nymphs found in branches and adults caught in traps presented an aggregated distribution. Sequential sampling plans were developed for nymphs and adults in regions with and without HLB, and the maximum number of samples for decision making was 264 and 83 samples for nymphs in regions with and without the disease, and, 184 and 150 samples for adults, in regions with and without the disease, respectively.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES