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61.
Martínez Vidal JL Egea González FJ Garrido Frenich A Martínez Galera M Aguilera PA López Carrique E 《Pest management science》2002,58(8):784-790
Principal component analysis (PCA) was applied to the gas chromatographic data obtained from 23 different greenhouse trials. This was used to establish which factors, including application technique (very small, small, medium and large drop-size), crop characteristics (short/tall, thin/dense) and pattern application of the operator (walking towards or away from the treated area) are relevant to the dermal exposure levels of greenhouse applicators. The results showed that the highest exposure by pesticides during field applications in greenhouses, in the climatic conditions and in the crop conditions typical of a southern European country, occurs on the lower legs and front thighs of the applicators. Similar results were obtained by hierarchical cluster analysis (HCA). Drop-size seems to be very important in determining total exposure, while height and density of crops have little influence on total exposure under the conditions of the present study. No pesticide type is a major factor in total exposure. The application of multiple regression analysis (MRA) allowed assessment of the relationships between the pesticide exposure of the less affected parts of the body with the most affected parts. 相似文献
62.
Gabriela Claudia Cangahuala-Inocente Lírio Luiz Dal Vesco Douglas Steinmacher Antonio Carlos Torres Miguel Pedro Guerra 《Scientia Horticulturae》2007
Pineapple guava (Acca sellowiana) syn. Feijoa sellowiana, a Brazilian indigenous Myrtaceae is under domestication in South Brazil. Previous works showed that this species is responsive to somatic embryogenesis and recalcitrant to conventional methods of clonal propagation. In the present work it was evaluated the role of components of culture medium in the induction and development of somatic embryos. The technology of synthetic seeds was also evaluated. Zygotic embryos were inoculated in LPm medium supplemented with 8 mM glutamic acid and 8 mM l-glutamine, 2,4-dichlophenoxiacetic acid (20 μM) and myo-inositol. For conversion of somatic embryos and synthetic seeds it was tested the effect of 6-benzylaminopurine and gibberellic acid combined or not with activated charcoal. The highest values for embryogenetic induction (100%) and number of somatic embryos/explant (113) were observed in the LPm medium supplemented with Glu (8 mM), and 2,4-D. The culture medium supplemented with BA (0.5 μM) and GA3 (1 μM) and activated charcoal (1.5 g L−1) enhanced the conversion of somatic embryos to plantlets. Pre-germinated somatic embryos encapsulated in sodium alginate with BA (0.5 μM) and GA3 (1 μM) developed radicles. The use of synthetic seed was a requisite for the survival of plantlets. 相似文献
63.
Control of black foot disease in grapevine nurseries 总被引:1,自引:0,他引:1
Black foot disease of grapevines is a decline and dieback disease caused by a soilborne pathogen complex including Cylindrocarpon liriodendri , C. macrodidymum , Campylocarpon fasciculare and Campyl. pseudofasciculare . These pathogens cause primary infections of roots and basal ends of grafted cuttings in nursery soils. Thirteen fungicides were screened in vitro for mycelial inhibition of these pathogens. Prochloraz manganese chloride, benomyl, flusilazole and imazalil were the most effective fungicides tested, and were subsequently included in semi-commercial field trials. Basal ends of grafted cuttings were dipped in various chemical and biological treatments prior to planting in open-rooted nurseries. Black foot pathogens were not isolated from grafted cuttings prior to planting. Additional treatments involved soil amendments with Trichoderma formulations and hot water treatment of dormant nursery grapevines. Field trials were evaluated after eight months. Isolations from uprooted plants revealed low levels of black foot pathogens in the roots of untreated control plants, and significantly higher levels in basal ends of rootstocks. The incidence of black foot pathogens, as well as that of Petri disease pathogens, was not significantly and/or consistently reduced by the majority of chemical or biological treatments. However, these pathogens were not isolated from uprooted plants that were subjected to hot water treatment. It is therefore recommended that hot water treatment of dormant nursery plants be included in an integrated strategy for the proactive management of these diseases in grapevine nurseries. 相似文献
64.
Silvio Aparecido Lopes Guilherme Fernando Frare Pedro Takao Yamamoto Antonio Juliano Ayres José Carlos Barbosa 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(4):463-468
The huanglongbing (HLB) disease of citrus trees, caused by Candidatus Liberibacter asiaticus and Ca. Liberibacter americanus, was first reported in Brazil in March, 2004. The presence of the disease has caused serious concerns
among growers. Pruning experiments were conducted to determine if removal of symptomatic branches or the entire canopy (decapitation)
would eliminate infected tissues and save HLB-affected trees. Pruning was done in five blocks on a total of 592 3- to 16 year-old
‘Valência’, ‘Hamlin’ or ‘Pêra’ sweet orange trees showing no symptoms or with two levels of symptom severity. Ten decapitated
trees per block were caged and all trees were treated with insecticides to control the psyllid vector, Diaphorina citri. Mottled leaves reappeared on most symptomatic (69.2%) as well on some asymptomatic (7.6%) pruned trees, regardless of age,
variety, and pruning procedure. Presence of the pathogen (Ca. Liberibacter americanus) in all symptomatic trees was confirmed by PCR. In general, the greater the symptom severity before
pruning the lower the percentage of trees that remained asymptomatic after pruning. 相似文献
65.
Lima Pedro Paulo Arcanjo Narciso Luis Gustavo Alcindo Jefferson Filgueira Deschk Maurício Ciarlini Paulo Cesar dos Santos Paulo Sérgio Patto de Almeida Breno Fernando Martins 《Veterinary research communications》2022,46(1):27-35
Veterinary Research Communications - Propofol is a widely used drug in veterinary medicine to induce anesthesia; as well as the chosen compound for protocols of intravenous anesthesia. The present... 相似文献
66.
To determine if flower nutrient composition can be used to predict fruit quality, a field experiment was conducted over three seasons (1996-1999) in a commercial orange orchard (Citrus sinensis (L.) Osbeck cv. 'Valencia Late', budded on Troyer citrange rootstock) established on a calcareous soil in southern Portugal. Flowers were collected from 20 trees during full bloom in April and their nutrient composition determined, and fruits were harvested the following March and their quality evaluated. Patterns of covariation in flower nutrient concentrations and in fruit quality variables were evaluated by principal component analysis. Regression models relating fruit quality variables to flower nutrient composition were developed by stepwise selection procedures. The predictive power of the regression models was evaluated with an independent data set. Nutrient composition of flowers at full bloom could be used to predict the fruit quality variables fresh fruit mass and maturation index in the following year. Magnesium, Ca and Zn concentrations measured in flowers were related to fruit fresh mass estimations and N, P, Mg and Fe concentrations were related to fruit maturation index. We also established reference values for the nutrient composition of flowers based on measurements made in trees that produced large (> 76 mm in diameter) fruit. 相似文献
67.
Applications of growth retardants, daminozide and CCC (chlormequatchloride), were studied in order to determine their effects on morphology and post-planting growth of silver birch (Betula pendula Roth) container seedlings. Daminozide was sprayed once (on 28 June at concentrations of 1.0 – 6.0 g l–1) and CCC was sprayed twice (on 29 June and 27 July at concentrations of 0.5–3.0 gl–1). Height growth, morphology of seedlings at the end of the growing season, the shoot and root growth potential the following spring and field performance during the following seasons were measured. During the first summer in the nursery, both daminozide and CCC retarded height growth,but daminozide was more effective. The effects of compounds on stem diameter during the summer of application were small. Neither of the compounds affected the field performance of seedlings. The most suitable applications for retardation of height growth, without negative effects on other morphological variables, were 4 g l–1 (32 mg per seedling) for daminozide and 2 g l–1 (16 mg per seedling), sprayed in two applications, for CCC. 相似文献
68.
Field performance of silver-birch planting-stock grown at different spacing and in containers of different volume 总被引:1,自引:0,他引:1
Silver birch seedlings were grown in two types of trays differing incell volume. For each kind of tray, three different spacings were achieved bygrowing seedlings in all, half or one quarter of the cells. The planting-stockso produced was out-planted at two forest sites and growth followed for fiveyears. Container size had a large effect on seedling morphology and on fieldperformance. Density also had a large effect on seedling morphology, but littleinfluence on performance. The tightest relationship of field performance was tothe mean dry weight of the stems of the planting stock (R2 = 0.94).Mean height and sturdiness index, defined as diameter ÷height, were not correlated with performance. Of the non-destructivemeasurements, mean root-collar diameter was the most closely correlated withperformance. 相似文献
69.
Felipe Nogueira Soares Maria Emilia Franco Oliveira Luciana Cristina Padilha-Nakaghi Luís Guilherme de Oliveira Marcus Antônio Rossi Feliciano Felipe Brener Bezerra de Oliveira Pedro Paulo Maia Teixeira Wilter Ricardo Russiano Vicente Cristian Faturi Luiz Fernando de Souza Rodrigues 《Tropical animal health and production》2015,47(8):1465-1471
70.