scholarly journals Factors affecting the local distribution of Polystigma rubrum stromata on Prunus spinosa

2018 ◽  
Vol 151 (2) ◽  
pp. 278-283
Author(s):  
Hattie R. Roberts ◽  
Sara E. Pidcock ◽  
Sky C. Redhead ◽  
Emily Richards ◽  
Kevin O’Shaughnessy ◽  
...  
Keyword(s):  
Leaf Surface ◽  
Early 20Th Century ◽  
Local Distribution ◽  
Factors Affecting ◽  
Prunus Spinosa ◽  
Gall Mite ◽  
Western Ireland ◽  
Winter Flooding ◽  
Individual Trees ◽  
Field Location

Background and aims – Polystigma rubrum forms orange-red stromata on the surface of living leaves of Prunus spinosa and P. domestica. Records suggests that this fungus now has a much more limited distribution in Britain than recorded in the 19th and early 20th century. Methods – We studied the local distribution of the fungus in the Burren Hills of western Ireland where it remains very common. Key results – Assessment of the local distribution of the fungus over two years found stromata to occur more frequently on P. spinosa leaves in hedgerows than woodlands. On individual trees in areas of open limestone pavement, the frequency of stromata was ten times higher in 2016 than 2015, possibly related to interannual rainfall differences. On hedgerow trees subjected to winter flooding, stromata were much less abundant, whereas stromata were more abundant on leaves also infected by the gall mite Eriophyes prunispinosae. The identity of Po. rubrum was confirmed by ITS sequencing.Conclusion – At a field location where Po. rubrum stromata are present in unusually high abundance, the distribution of stromata on trees in different habitats showed high levels of variation linked to both habitat and the presence of gall mites. Further work is required to determine whether variation in leaf surface and soil moisture are the key determinants of the observed distribution. Such investigations may reveal why Po. rubrum, once common in northern Europe is now restricted mainly to westerly, coastal locations.

scholarly journals High energy surface as a receptor in electrospinning: A good switch for hydrophobicity to hydrophilicity

2021 ◽  
pp. 107-107
Author(s):  
Xiao-Xia Li ◽  
Dan Tian ◽  
Ji-Huan He
Keyword(s):  
Energy Surface ◽  
Leaf Surface ◽  
High Energy ◽  
Water Molecules ◽  
Lotus Effect ◽  
Factors Affecting ◽  
Lotus Leaf ◽  
Wetting Property ◽  
Modified Surface ◽  
Main Factors

The lotus leaf surface is modified by covering nanofibers to check its wetting property. The well-known lotus effect of the modified surface is greatly weakened, and a hydrophilic property is found. The geometric potential theory is used to explain the phenomenon, it shows that the two adjacent nanofibers can produce a high geometric potential to push water molecules to move along the fibers, as a result, a hydrophilic surface is predicted after surface modification. An experiment is designed to elucidate the main factors affecting the wetting property of the modified surface of lotus leaf.

Investigating the Wettability of Rapeseed Leaves

2021 ◽  
Vol 37 (3) ◽  
pp. 399-409
Author(s):  
Yong He ◽  
Jianjian Wu ◽  
Shupei Xiao ◽  
Hui Fang ◽  
Qishuai Zheng
Keyword(s):  
Surface Tension ◽  
Free Energy ◽  
Significant Influence ◽  
Leaf Surface ◽  
Contact Angles ◽  
List Type ◽  
Factors Affecting ◽  
Spray Droplets ◽  
Droplet Sizes ◽  
Leaf Wettability

HighlightsContact angles of spray droplets were positively correlated with their surface tension.Wettability of rape leaves was generally poor for most pesticides.Surface structure and free energy determine the hydrophobicity of rape leaves.The size of the spray droplets had no significant influence on rape leaf wettability.Abstract. In order to improve the deposition and adherence of spray droplets on leaf surfaces, the wettability of rapeseed leaves was investigated. We explored the effect of different pesticides and test surfaces on droplet contact angles, and analyzed the effects of leaf surface properties, droplet sizes and the addition of organosilicone adjuvant on wettability. The results indicated that contact angles of different liquids were positively correlated with their surface tension for rapeseed leaves. The wettability of rapeseed leaves was generally poor using different pesticides, but was highest for a fungicide mixture of difenoconazole and propiconazole. The hydrophobicity of rapeseed leaves is largely determined by the complex microstructure and the low surface free energy of the leaves. The size of the spray droplets had no significant influence on the wettability. Moreover, the addition of an organosilicone adjuvant significantly reduced the surface tension of all spray droplets, with the best result for a 50% procymidone solution. In conclusion, the factors affecting rapeseed leaf surface wettability should be considered comprehensively before selecting the appropriate pesticide, so as to improve its utilization rates. Keywords: Contact angle, Leaf surface, Pesticide application, Spray droplet.

Navstar GPS – Charting Aspects

1992 ◽  
Vol 45 (3) ◽  
pp. 344-351
Author(s):  
Nigel R. L. Gooding
Keyword(s):  
Global Positioning System ◽  
Historical Development ◽  
Data Availability ◽  
Early 20Th Century ◽  
Positioning System ◽  
New Developments ◽  
Factors Affecting ◽  
Global Positioning ◽  
The World ◽  
Proper Consideration

The historical development of positioning in relation to the nautical chart is very briefly described. Present nautical charts are largely based on geodetic surveys which date from the 19th and early 20th century. This gave rise to the use of many local datums and there has been a need to provide the mariner with information to enable him to transfer his position from one chart to an adjacent one on a different datum. The sizes of discrepancies in position between various datums are given. The availability of the Global Positioning System (GPS) and the World Geodetic System 1984 (WGS 84) datum enables positioning on a single worldwide datum to become a reality. The important factors affecting the adoption of WGS 84 as the datum for nautical charts, namely data availability and the practical and political considerations, are discussed. The importance of the proper consideration of datum in relation to new developments in the use of nautical charts is also mentioned.

scholarly journals Factors Affecting Reductions in Photosynthesis Caused by Applying Horticultural Oil to Grapevine Leaves

HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 346-351 ◽  
Author(s):  
Anton Baudoin ◽  
Sarah Finger McDonald ◽  
Tony K. Wolf
Keyword(s):  
Leaf Surface ◽  
Net Photosynthesis ◽  
Soluble Solids ◽  
Retention Data ◽  
Foliar Injury ◽  
Visible Injury ◽  
Factors Affecting ◽  
Small Water ◽  
Significant Difference ◽  
Leaf Surfaces

Phytotoxicity of horticultural oil, applied shortly before antifungal sulfur, was evaluated for 23 grape cultivars. Oil application significantly reduced accumulation of soluble solids in berries of 9 of 23 cultivars, but there was no relationship with visible foliar injury. Treatment of leaves of Vitis labrusca `Catawba' with 1.5% JMS Stylet-Oil reduced leaf net photosynthesis (Pn) by 50% to 60% and of Vitis vinifera `Chardonnay' by 20% to 30% 1 day after application. Pn was reduced only when the lower (abaxial) leaf surface was treated; treatment of only the adaxial leaf surface had little effect. The Pn depression in `Catawba' persisted 3 to 4 weeks, whereas reductions in `Chardonnay' persisted less than 2 weeks. The Pn-depressing effect of oil was not significantly ameliorated by real or simulated rainfall, and washing the lower leaf surfaces with water and detergent also had only limited effect. There was no significant difference in Pn depression from oil applications made in the middle of the day (stomata open) compared to application in the evening (stomata closed), or from oil applied at higher versus lower application pressure. The greater sensitivity of `Catawba' than `Chardonnay' to Pn depression by oil may be related to the amount of oil retained by the leaves; the pubescent lower leaf surfaces of `Catawba' retained more than twice as much spray emulsion as did the more glabrous leaves of `Chardonnay'. Visible injury was mild in both cultivars, with small water-soaked lesions developing more commonly on `Chardonnay' than on `Catawba' leaves. Spray oil retention data for additional cultivars suggested that differences in retention can explain a portion of the differences in horticultural oil phytotoxicity.

Factors affecting variation in outcrossing rate in Eucalyptus globulus

2004 ◽  
Vol 52 (6) ◽  
pp. 773 ◽  
Author(s):  
Briony Patterson ◽  
René E. Vaillancourt ◽  
David J. Pilbeam ◽  
Brad M. Potts
Keyword(s):  
Eucalyptus Globulus ◽  
Seed Orchard ◽  
Forest Tree ◽  
Self Incompatibility ◽  
Factors Affecting ◽  
Seed Collection ◽  
Clonal Seed Orchard ◽  
Canopy Position ◽  
Outcrossing Rates ◽  
Individual Trees

The mating system of the animal-pollinated forest tree species Eucalyptus globulus Labill. was investigated in a clonal seed orchard to determine the importance of self-incompatibility, floral timing, floral abundance and canopy position on explaining variation in outcrossing rates. Outcrossing rates were highly and significantly correlated with the degree of self-incompatibility of individual genotypes (R2 = 0.92). Outcrossing rates were also significantly higher in the upper than in the lower parts of tree canopies (0.78 ± 0.1 and 0.54 ± 0.1, respectively). In contrast, neither flowering time nor abundance of flowers on individual trees revealed consistent effects upon outcrossing rates, suggesting that these factors are either less important or inherently more unpredictable because their effects partly depend on complex interactions with animal pollinators. Screening seed orchards in order to identify trees with high self-incompatibility and restricting seed collection to these trees will ensure that a high proportion of the seed used for plantations is derived from outcrossing, thereby minimising the deleterious effects of inbreeding depression.

scholarly journals Mass attack by the ambrosia beetle Platypus quercivorus occurs in single trees and in groups of trees

2014 ◽  
Vol 44 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Michimasa Yamasaki ◽  
Yasuto Ito ◽  
Makoto Ando
Keyword(s):  
Mixed Model ◽  
Secondary Forest ◽  
Ambrosia Beetle ◽  
Negative Effects ◽  
Quercus Crispula ◽  
Factors Affecting ◽  
Platypus Quercivorus ◽  
Bark And Ambrosia Beetles ◽  
Mass Attack ◽  
Individual Trees

Bark and ambrosia beetles sometimes kill trees by attacking them en masse; however, their attack is not necessarily successful. Less than half of the fagaceous trees attacked by the ambrosia beetle Platypus quercivorus (Murayama) die, and the factors affecting this mortality are still unknown. To examine this issue, the survival of all stems of fagaceous trees attacked by the ambrosia beetle was investigated in a secondary forest from 2008 to 2010. In an area of 93 ha, 2130 stems (1278 genets) of fagaceous trees were attacked by P. quercivorus during the study period, and 813 of these stems died. A generalized additive mixed model was constructed to predict the probability of mortality of the attacked stems. A best-fit model showed that the probability of mortality was higher in Quercus crispula Blume than in Castanea crenata Sieb. & Zucc. A positive correlation was determined between the density of the attacked trees and the probability of mortality, suggesting that mass attack of P. quercivorus occurs not only on individual trees, but also on groups of trees. Assuming that trees attacked earlier in the season have a higher probability of mortality, the observed negative effects of altitude suggest that P. quercivorus initially seeks hosts at lower elevations.

scholarly journals INDUSTRI KERAMIK TRADISIONAL CINA DI SAKKOK, SINGKAWANG 1933-2000

2013 ◽  
Vol 5 (2) ◽  
pp. 217
Author(s):  
Any Rahmayani
Keyword(s):  
20Th Century ◽  
Historical Perspective ◽  
Ceramic Industry ◽  
Raw Materials ◽  
Early 20Th Century ◽  
Factors Affecting ◽  
West Kalimantan ◽  
The Social ◽  
Political Conditions ◽  
Ceramics Industry

AbstrakPenelitian ini menyajikan tentang dinamika industri keramik tradisional Cina di Sakkok, sebuah wilayah di Kota Singkawang, Provinsi Kalimantan Barat sepanjang abad ke-20. Latar belakang penelitian ini adalah keberadaan industri keramik tradisional Cina di Sakkok yang sedang digarap sebagai aset ekonomi dan pariwisata bagi Singkawang. Permasalahan pokok yang dibahas adalah dinamika industri keramik tradisional Cina di Sakkok, Singkawang dalam perspektif sejarah. Tujuan dari kajian ini yaitu menggambarkan tentang tradisi pembuatan keramik tradisional Cina di Sakkok, menguraikan perintisan industri keramik tradisional Cina pada awal abad ke-20 dan menjelaskan faktor-faktor yang mempengaruhi industri ini. Metode yang digunakan metode heuristik, kritik, interpretasi dan historiografi. Hasil penelitian menunjukkan bahwa ciri tradisional keramik Cina yang terlihat pada bahan bakunya, peralatan proses proses pembentukan, penglasiran,dan pembakaran, motif dan desain, serta alat pembakaran yang disebut tungku naga. Perubahan yang terkait dengan ketersediaan bahan baku, bahan penunjang dan teknik pembakaran serta kondisi sosial politik membawa dampak bagi keberlangsungan industri keramik tradisional Cina dari Singkawang ini.AbstractThis study presents the dynamics of traditional Chinese ceramics industry in Sakkok, Singkawang, in the Province of West Kalimantan during the 20th century. The background of this research is the existence of traditional Chinese ceramics industry in Sakkok which is being worked on as an economic and tourism asset for Singkawang. The main problem for this study is the historical perspective of the dynamics of traditional Chinese ceramics industry in Sakkok. The purpose of this study is describing the tradition of producing traditionalChinese ceramics in Sakkok, outlining pioneering in the industry in the early 20th century, and explaining the factors affecting it. The author used heuristic, criticism, interpretation and historiography. The results showed that the characteristics of traditional Chinese ceramics are depicted in the raw materials, equipment, processes of formation, glazing, and burning, motifs and designs, as well as burning tool called dragon furnace. Changes related to the availability of raw and auxiliary materials, burning techniques as well as the social and political conditions have impact on the sustainability of traditional Chinese ceramic industry in Singkawang.

Sign in / Sign up

Export Citation Format

Share Document