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101.
Francisco de Assis Alves Mourão Filho Erick Espinoza-Núñez Eduardo Sanches Stuchi Edwin Moisés Marcos Ortega 《Scientia Horticulturae》2007
Vegetative growth, yield, and fruit quality of ‘Fallglo’ and ‘Sunburst’ mandarins on ‘Rangpur’ lime, ‘Swingle’ citrumelo, ‘Orlando’ tangelo, and ‘Cleopatra’ mandarin were evaluated under subtropical climate of Northern São Paulo State, Brazil, from 2000 through 2006 harvest seasons. ‘Fallglo’ mandarin trees had the highest cumulative yield on ‘Rangpur’ lime, and the smallest on ‘Swingle’ citrumelo and ‘Orlando’ tangelo. Plants of this cultivar had the highest yield efficiency on ‘Rangpur’ lime, and the lowest on ‘Orlando’ tangelo. ‘Sunburst’ mandarin trees began to bear fruits later than ‘Fallglo’ mandarin trees, with no differences in yield induced by the rootstocks. ‘Cleopatra’ mandarin induced the most vigorous growth in ‘Fallglo’ mandarin as compared to plants on ‘Swingle’ citrumelo. On the other hand, the largest trees of ‘Sunburst’ mandarin were registered on ‘Orlando’ tangelo, and the smallest on ‘Rangpur’ lime. ‘Sunburst’ mandarin had higher alternate bearing than ‘Fallglo’ regardless the rootstock. Fruit weight and juice content were not affected by the rootstock. These two mandarin scion cultivars may be considered adequate alternatives to produce good fruit quality for the fresh fruit market. ‘Cleopatra’ mandarin and ‘Rangpur lime are suitable rootstocks for ‘Fallglo’ mandarin, whereas all rootstocks evaluated are adequate for ‘Sunburst’ mandarin. 相似文献
102.
Evaluation of biological control agents for managing cucurbit powdery mildew on greenhouse-grown melon 总被引:1,自引:0,他引:1
D. Romero A. de Vicente H. Zeriouh F. M. Cazorla D. Fernández-Ortuño J. A. Torés A. Pérez-García 《Plant pathology》2007,56(6):976-986
An evaluation was made of the ability of two mycoparasite-based products AQ10® ( Ampelomyces quisqualis ) and Mycotal® ( Lecanicillium lecanii ), as well as three strains of Bacillus subtilis , to manage powdery mildew disease, caused by Podosphaera fusca on melon seedlings maintained under different regimes of relative humidity and on plants grown under greenhouse conditions in Spain. In every case fungal and bacterial biocontrol agents (BCAs) performed better under conditions of high relative humidity (90–95% RH). In greenhouse experiments, the effectiveness of the mycoparasites to manage powdery mildew was absolutely dependent on mineral oil. The strains of B. subtilis provided disease control similar to that achieved with the mycoparasites or the fungicide azoxystrobin. Microscopic analysis showed the ability of these bacterial strains to efficiently colonize leaf surfaces and revealed the occurrence of antagonistic interactions between biological agents and P. fusca structures. These results confirmed the usefulness of these BCAs for managing powdery mildew on greenhouse-grown cucurbits either as single products or as a component of integrated control programmes. 相似文献
103.
Vulnerability of xylem to loss of hydraulic conductivity caused by drought-induced cavitation was determined for three riparian cottonwood species in Lethbridge, Alberta: Populus deltoides Bartr., P. balsamifera L., and P. angustifolia James. These species suffered 50% loss of hydraulic conductivity in one-year-old stem segments when xylem pressure potential fell to -0.7 MPa for P. deltoides and -1.7 MPa for P. balsamifera and P. angustifolia, making them the three most vulnerable tree species reported so far in North America. The possible contribution of drought-induced xylem dysfunction to the decline of riparian ecosystems in dammed rivers is discussed. 相似文献
104.
em. o. Univ.-Prof. Dr. A. Kurir 《Journal of pest science》1983,56(7):125-128
During the last 12 years Arborvitae Leaf Miner (Argyresthia thuiella) was imported from North America to Western- and Central-Europe (1971 the Netherlands, 1975 Federal Republic Germany and 1976 Austria) onThuja occidentalis L. (Cupressacea). In Lower Austria and Vienna there is a tendency rapid to the east, through the dominate westerly winds. Fligh-time took 27 days, moth-slip was 5–10 h in the morning; maximum about 5–6 h. Index of sexus was displated in favour of the males (51.7–66.7%). The moths fed with water-honey showed a longaevitas of 1–15 days maximum about 4 days, and fed with pure water of 8 days. Attack-degree (variational limit) amounted to 2.6–24.5%. The parasitism-role (Necremnus sp., Eulophidae) was between 1.2% and 15.7%. In the laboratory chemical-therapeutics in spray form were without effect. Author's opinion is that this eminent exotic injurious insect must already be calculated as a part of the European fauna. 相似文献
105.
Ecballium elaterium fruit juice is used for the treatment of sinusitis in Turkish folk medicine. The aim of this study was to increase the yield of cucurbitacin B, an anti-inflammatory compound previously isolated in various organs of E. elaterium, through tissue culture techniques. Higher yields of cucurbitacin B (1.126%) were obtained from the first subculture calluses from stem nodes in the presence of benzyl adenine (BA; 1 mg/l) and naphtalene acetic acid (NAA; 0.1 mg/l) in comparison with the yields obtained from plant material (0.01%). 相似文献
106.
Hydraulic architecture parameters, water relation parameters and wood anatomy were studied in roots and shoots of the flood-tolerant tree Annona glabra L. on Barro Colorado Island, Panama. Hydraulic conductivity, leaf specific conductivity, and Huber value were similar to the corresponding values for tree species living in non-flooded habitats. The vulnerability of stems to loss of hydraulic conductivity resulting from embolism was low (50% loss of conductivity at -3.3 MPa). The lowest leaf water potential measured in the field was about -1.0 MPa, indicating that A. glabra has a large margin of safety from embolism, which may provide protection against rare drought events, or may be an adaptation to brackish mangrove habitats. Low absolute conductivity of roots was compensated for by an increase in the number of roots. More than two-thirds of whole-plant resistance to water flow was located in the roots. 相似文献
107.
Rauter AP Filipe MM Prata C Noronha JP Sampayo MA Justino J Bermejo J 《Fitoterapia》2005,76(5):433-438
Diacronema sp. was cultured and its sterols were separated by column chromatography on silica gel. The new sterol 24-ethyl-4alpha-methyl-cholestane-3,20-diol (1) was characterised by NMR and MS spectrometry, as well as (22E)-24-ethyl-4alpha-methyl-5alpha-cholest-22-en-3beta-ol (2) and beta-sitosterol, the major components of the sterol fractions. Neither the biosynthetic origin of the new dihydroxysterol nor its role in the biochemistry of Diacronema is known. 相似文献
108.
Seasonal variation of inorganic nitrogen and net mineralization in a salt marsh ecosystem 总被引:6,自引:0,他引:6
Inorganic nitrogen pools and net mineralization were estimated in three sites of a Tagus estuary salt marsh in Portugal throughout 1 year. Ammonium (NH4
+) was the major form of inorganic nitrogen found in the salt marsh soil. Extractable NH4
+ concentrations showed a marked seasonal pattern with a concentration peak during the hotter months of July/August. The great majority (>99%) of the total nitrogen in the soil was found in sedimented organic matter, not readily available for plant uptake. Net nitrogen mineralization, determined using a field incubation method, showed a peak during the months of June/July which resulted in an increase on nitrogen availability. With the exception of the lower salt marsh, estimated rates of in situ net nitrogen mineralization in the soil during summer were well related to the increase in plant aboveground biomass and plant nitrogen pools, indicating that the process is an important source of available nitrogen for plant uptake and growth. Annual net nitrogen mineralization ranged between 2.4 and 4.5gNm–2yr– 1 being significantly higher for the lower salt marsh site. Rates of net nitrogen mineralization were relatively low during most of the year with a particularly active period from June to August, possibly due to an effect of temperature on soil microbial activity. 相似文献
109.
Alexandre Behling Carlos Roberto Sanquetta Ana Paula Dalla Corte Sylvio Péllico Netto Aurélio Lourenço Rodrigues Bráulio Otomar Caron Augusto Arlindo Simon 《林业研究》2016,27(6):1211-1217
The amount of photosynthetic radiation intercepted by a crop is a function of the incident solar radiation on the plants, the leaf area index (L AI), and the light extinction coefficient (k). We quantified L AI and k in stands of black wattle (Acacia mearnsii De Wild.) over a 7-year growth cycle at two locations in the state of Rio Grande do Sul, Brazil. Our study was conducted in commercial stands in agroecological regions with high densities of black wattle plantations. L AI was calculated as the ratio between the leaf area of a tree and its planting space, and k was derived from Beer’s law. L AI depends on the planting site and stand age. Between the two sites, the L AI was similar over time, the amount of variation differed. Values of k depended only on stand age, with the highest average observed for stands up to 5 years old. The trend of k during the plantation cycle was inversely proportional to L AI and was correlated with L AI, leaf area, leaf dry mass, canopy volume, height, branches dry mass, total dry mass, and crown diameter. 相似文献
110.