scholarly journals TENACITY AND PERSISTENCE OF COPPER FUNGICIDES IN CITRUS SEEDLINGS UNDER SIMULATED RAINFALL

2016 ◽  
Vol 29 (3) ◽  
pp. 677-684 ◽  
Author(s):  
ANTONIO EDUARDO FONSECA ◽  
BRUNO DE MORAES NUNES ◽  
JOÃO BATISTA FERREIRA JÚNIOR
Keyword(s):  
Surface Tension ◽  
Copper Content ◽  
Plant Pathogens ◽  
Leaf Surface ◽  
Control Plant ◽  
Simulated Rainfall ◽  
Copper Fungicides ◽  
Main Factors ◽  
Citrus Leaves ◽  
Active Residue

ABSTRACT The amount of fungicide that adheres to the leaf during spraying and the amount that remain on the leaf after weathering are the main factors that defines the amount of active residue on the leaf surface to effectively control plant pathogens. Thus, the objective of this work was to evaluate the tenacity and persistence of copper in citrus seedling leaves under simulated rainfall in Jaboticabal, State of São Paulo, Brazil. The evaluated variables were copper content, solution retention, surface tension and drop spectrum. A significant and inversely proportional linear relationship to drops <100 µm was found. The percentage of copper retained in leaves of citrus seedlings with copper fungicides of suspension concentrate (SC) formulations after simulated rainfall was greater than 80%. Copper fungicides of SC formulations presented the lowest surface tension, allowing greater tenacity and persistence of copper on seedlings of citrus leaves after simulated rainfall and increased contact between the drops and leaf surface.

scholarly journals The effect of copper fungicides on the rate of photosynthesis and the transpiration of hop plants

2011 ◽  
pp. 117-123
Author(s):  
Jaroslav Pokorny ◽  
Josef Pulkrábek ◽  
Karel Krofta ◽  
Josef Ježek
Keyword(s):  
Photosynthetic Rate ◽  
Copper Content ◽  
Copper Fungicides ◽  
Before And After ◽  
Elemental Copper ◽  
Rate Of Photosynthesis ◽  
Accredited Laboratory ◽  
Effect Of Copper ◽  
Copper Fungicide ◽  
Infrared Analyzer

The paper evaluates the effect of copper fungicide spraying on the rate of photosynthesis and transpiration of hops, the influence of spraying on the elemental copper content in the leaves and cones hop variety Agnus. Photosynthetic rate was measured by LC pro+ (infrared analyzer) in the Hop Research Institute Saaz in the field in some periods of 2008, 2009 and 2010. Dry cones and leaf samples (taken before and after application of copper fungicides) were analyzed in an accredited laboratory for elemental copper.

scholarly journals PRODUCTION AND FUNGICIDAL ACTIVITY ASSESMENT OF WOOD-WASTE LIQUID SMOKE

2020 ◽  
Vol 8 (10) ◽  
pp. 285-291
Author(s):  
Budy Rahmat ◽  
Dedi Natawijaya ◽  
Endang Surahman
Keyword(s):  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Block Design ◽  
Control Plant ◽  
Wood Waste ◽  
In Vitro Test ◽  
In Vivo Test ◽  
Liquid Smoke

Liquid smoke is known to contain compounds that can control plant disease pathogens. This study aims to produce wood-waste liquid smoke and determine its effectiveness as a fungicide on plant pathogens. This research was conducted in two experimental stages, namely: (i) in vitro test as a preliminary test of the effectiveness of teak waste liquid smoke at concentrations of 0, 0.5, 1, 1.5, 2, and 2.5%; and (ii) in vivo test was arranged in randomized block design consisting of seven levels of liquid smoke concentration, namely 0, 1, 2, 3, 4, 5, and 6%, each of which was repeated four times. The results showed that the pyrolysis of 1 kg of wood waste was produced with the proportions of liquid smoke, charcoal and tar, respectively: 312 mL, 31 g, 367 g and the uncondensed gases. Treatment of liquid smoke in the in vivo test showed that a concentration of 1 to 2.5% liquid smoke was able to suppress the growth of the pathogenic fungus Sclerotium rolfsii 100%. The treatment of liquid smoke in the in vivo test showed an effect on inhibition of the growth diameter of fungal colonies, suppressing the disease occurance, and suppressing the lesion diameter.

Design Parameters for Superhydrophobicity and Superoleophobicity

MRS Bulletin ◽  
2008 ◽  
Vol 33 (8) ◽  
pp. 752-758 ◽  
Author(s):  
Anish Tuteja ◽  
Wonjae Choi ◽  
Gareth H. McKinley ◽  
Robert E. Cohen ◽  
Michael F. Rubner
Keyword(s):  
Surface Tension ◽  
Surface Topography ◽  
Leaf Surface ◽  
Contact Angles ◽  
Design Parameters ◽  
Lotus Leaf ◽  
General Design ◽  
Composite Interface

AbstractRecent experiments have revealed that the wax on the lotus leaf surface, by itself, is weakly hydrophilic, even though the lotus leaf is known to be superhydrophobic. Conventional understanding suggests that a surface of such waxy composition should not be able to support superhydrophobicity and high contact angles between a liquid and the surface. Here, we show that the unexpected superhydrophobicity is related to the presence of “reentrant texture” (that is, a multivalued surface topography) on the surface of the lotus leaf. We exploit this understanding to enable the development of superoleophobic surfaces (i.e., surfaces that repel extremely low-surface-tension liquids, such as various alkanes), where essentially no naturally oleophobic materials exist. We also develop general design parameters that enable the evaluation of the robustness of the composite interface on a particular surface. Based on these design parameters, we also rank various superhydrophobic and superoleophobic substrates discussed in the literature, with particular emphasis on surfaces developed from inherently hydrophilic or oleophilic materials.

scholarly journals Actinomycetes, promising tools to control plant diseases and to promote plant growth

2005 ◽  
Vol 82 (3) ◽  
pp. 85-102 ◽  
Author(s):  
C.L. Doumbou ◽  
M.K. Hamby Salove ◽  
D.L. Crawford ◽  
C. Beaulieu
Keyword(s):  
Plant Growth ◽  
Plant Pathogens ◽  
Soil Microbial Biomass ◽  
Extracellular Enzymes ◽  
Control Plant ◽  
Plant Diseases ◽  
Soil Microbial ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting

Actinomycetes represent a high proportion of the soil microbial biomass and have the capacity to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to protect plants against plant diseases. This review focuses on the potential of actinomycetes as (a) source of agroactive compounds, (b) plant growth promoting organisms, and (c) biocontrol tools of plant diseases. This review also addresses examples of biological control of fungal and bacterial plant pathogens by actinomycetes species which have already reached the market or are likely to be exploited commercially within the next few years.

Morphological and molecular based identification of Antifungal bacillus licheniformis

2017 ◽  
Vol 17 (1) ◽  
pp. 31-35
Author(s):  
B Oyuntogtokh ◽  
M Byambasuren
Keyword(s):  
Bacillus Licheniformis ◽  
Fungal Pathogens ◽  
Crop Production ◽  
Plant Pathogens ◽  
Control Plant ◽  
Plant Diseases ◽  
Bacillus Species ◽  
Bacterial Strains ◽  
Fusarium Spp ◽  
Bacterial Cultures

At present, plant diseases caused by soil borne plant pathogens have major constraints on crop production. Which include genera Fusarium spp, Phytophtora spp, Sclerotinia and Altenaria. Due to this reason, chemical fungicides are routinely used to control plant disease, which is also true in Mongolian case. However, use of these chemicals has caused various problems including environmental pollution with consequence of toxicity to human health also resistance of some pathogens to these fungicides are present. Fortunately, an alternative method to reduce the effect of these plant pathogens is the use of antagonist microorganisms. Therefore, some species of the genus Bacillus are recognized as one of the most effective biological control agent.Our research was focused to isolate Bacillus licheniformis, with antifungal potential, from indigenous sources. In the current study, 28 bacterial cultures were isolated from soil and fermented mare’s milk also named as koumiss. Isolated bacterial cultures were identified according to simplified key for the tentative identification of typical strain of Bacillus species. As a result 8 strains were positive and further screened for antifungal activity against Fusarium spp and Alternaria solani. Out of these 8 strains 5 strains are selected based on their high effectiveness against fungal pathogens and for further confirmation Polymerase Chain reaction run for effective bacterial strains using specific primers B.Lich-f and B.Lich-r. 

The Biocontrol Mechanism of Trichoderma asperellum Resistance Plant Pathogenic Fungi

2013 ◽  
Vol 726-731 ◽  
pp. 4525-4528
Author(s):  
Ping Yang ◽  
Qian Xu
Keyword(s):  
Cell Wall ◽  
Plant Pathogens ◽  
Control Plant ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Dry Weight ◽  
Plant Pathogenic Fungi ◽  
Cell Wall Degrading Enzymes ◽  
Antifungal Metabolites ◽  
Degrading Enzymes

T. asperellum is an important biocontrol fungus owing to their ability to antagonize plant pathogenic fungi. The biocontrol effects of T. asperellum were played by secreting many kinds of hydrolytic enzymes and antibiotics. T. asperellum producing more cell wall degrading enzymes when meeting plant pathogens. Moreover, the growth of the plant pathogens was inhibited by T. asperellum secondary metabolites. The yield of antibiotic 6-PP was 1.32 mg 6-PP/g mycelial dry weight. T. asperellum control plant pathogens through secreting cell wall degrading enzymes and producing antifungal metabolites.

scholarly journals Distribution pattern of developmental stages of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) on the surface of citrus leaves

2020 ◽  
Vol 1 (89) ◽  
pp. 1-6
Author(s):  
Meriem Dahmane ◽  
Gahdab Chakali
Keyword(s):  
Developmental Stages ◽  
Leaf Surface ◽  
Leaf Age ◽  
Pupal Stage ◽  
Phyllocnistis Citrella ◽  
Citrus Leafminer ◽  
Leaf Surfaces ◽  
Young Leaves ◽  
Citrus Orchards ◽  
Citrus Leaves

The leafminer Phyllocnistis citrella (Stainton, 1856) (Lepidoptera: Gracillariidae), is considered a potential serious pest of citrus in Algeria. The aim of this work was to investigate the relationship between the ecophases of the citrus leafminer and the leaf surface of the Washington navel citrus variety. Practically all the examined leaves of the young shoots were occupied by at least a developmental stage of this insect. More than 80% of the leafminer ecophases were distributed on the lower surfaces of the leaves. A relationship is highlighted between the leaf surfaces and the stages evolution of citrus leafminer. The choice of area laying by females is decisive for the survival and evolution of stages of development of the insect in relationship with leaf age. The analysis of the eggs distribution revealed that young leaves, with leaf surface smaller than 2 cm², were significantly preferred by females for oviposition. However, the larvae were abundant on leaf surfaces smaller than 6 cm² which provide a favorable environment for the development of larvae in order to realize their respective gallery. The pupal stage was observed almost uniformly on all the analyzed area classes. These results could contribute to the guidelines for pest risk assessment highlighting the intervention for the protection of citrus orchards against heavy infestations of Phyllocnistis citrella.

scholarly journals Field Identification and Management of Greasy Spot Disease

EDIS ◽  
2019 ◽  
Vol 2005 (10) ◽  
Author(s):  
S. H. Futch ◽  
L. W. Timmer
Keyword(s):  
Leaf Surface ◽  
Publication Date ◽  
Original Publication ◽  
Chlorotic Spot ◽  
Spot Disease ◽  
Field Identification ◽  
Infected Cells ◽  
Citrus Leaves

Greasy spot is a disease that's frequently found in tropical and semitropical regions where citrus cultivars are grown. The disease is caused by Mycosphaerella citri. Symptoms appear as yellow to dark brown to black lesions occurring first on the underside of mature citrus leaves (Fig. 1). As the lesions develop on the underside of the leaves, they become darker and a corresponding chlorotic spot will appear on the upper leaf surface. These yellow (chlorotic) spots occur when infected cells fail to develop chlorophyll. Lesions are more yellowish and diffuse on lemons and grapefruit and more raised and darker on tangerines. Affected leaves fall prematurely from the tree during the fall and winter resulting in reduced tree vigor and yield. Greasy spot also infects the fruit of grapefruit trees producing rind blotch.  This document is HS-1016, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date May 2005. HS-1016/HS263: Field Identification and Management of Greasy Spot Disease (ufl.edu)

scholarly journals Chaetomium Application in Agriculture

2021 ◽  
Author(s):  
Kasem Soytong ◽  
Somdej Kahonokmedhakul ◽  
Jiaojiao Song ◽  
Rujira Tongon
Keyword(s):  
Disease Control ◽  
Rice Blast ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Control Plant ◽  
Phytophthora Palmivora ◽  
Human Pathogens ◽  
Plant Disease Control ◽  
Different Strains ◽  
New Compounds

Chaetomium species for plant disease control are reported to be antagonize many plant pathogens. It is a new broad spectrum biological fungicide from Chaetomium species which firstly discovered and patented No. 6266, International Code: AO 1 N 25/12, and registered as Ketomium® mycofungicide for plant disease control in Thailand, Laos, Vietnam, Cambodia and China. Chaetoimum biofungicide and biostimulants are applied to implement integrated plant disease control. It showed protective and curative effects in controlling plant disease and promoting plant growth. It has been successfully applied to the infested soils with integrated cultural control for the long-term protection against rice blast (Magnaporte oryzae), durian and black Pepper rot (Piper nigram L.) (Phytophthora palmivora), citrus rot (Phytophthora parasitica) and strawberry rot (Fragaria spp.) caused by Phytophthora cactorum, wilt of tomato (Fusarium oxysporum f. sp. lycopersici), basal rot of corn (Sclerotium rolfsii) and anthracnose (Colletotrichum spp.) etc. Further research is reported on the other bioactive compounds from active strains of Chaetomium spp. We have discovered various new compounds from Ch. globosum, Ch. cupreum, Ch. elatum, Ch. cochliodes, Ch. brasiliense, Ch. lucknowense, Ch. longirostre and Ch. siamense. These new compounds are not only inhibiting human pathogens (anti-malaria, anti-tuberculosis, anti-cancer cell lines and anti-C. albicans etc) but also plant pathogens as well. These active natural products from different strains of Chaetomium spp. are further developed to be biodegradable nanoparticles from active metabolites as a new discovery of scientific investigation which used to induce plant immunity, namely microbial degradable nano-elicitors for inducing immunity through phytoalexin production in plants e.g. inducing tomato to produce alpha-tomaline against Fusarium wilt of tomato, capsidiol against chili anthracnose, sakuranitin and oryzalexin B against rice blast, scopletin and anthrocyaidin against Phytophthora or Pythium rot Durian and scoparone against Phytophthora or Pythium rot of citrus. Chaetomium biofungicide can be applied instead of toxic chemical fungicides to control plant diseases.

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.

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