ECONOMIC LOSSES CAUSED BY ROSE BEETLE MALADERA INSANABILIS (BRENSKE) ON FRUIT AND ORNAMENTAL PLANTS AND ITS CONTROL BY PATHOGENIC FUNGI

Bradysia species, commonly known as fungus gnats, are ubiquitous in greenhouses, nurseries of horticultural plants, and commercial mushroom houses, causing significant economic losses. Moreover, the insects from the Bradysia genus have a well-documented role in plant pathogenic fungi transmission. Here, a study on the potential of Bradysia impatiens to acquire and transmit the peanut stunt virus (PSV) from plant to plant was undertaken. Four-day-old larvae of B. impatiens were exposed to PSV-P strain by feeding on virus-infected leaves of Nicotiana benthamiana and then transferred to healthy plants in laboratory conditions. Using the reverse transcription-polymerase chain reaction (RT-PCR), real-time PCR (RT-qPCR), and digital droplet PCR (RT-ddPCR), the PSV RNAs in the larva, pupa, and imago of B. impatiens were detected and quantified. The presence of PSV genomic RNA strands as well as viral coat protein in N. benthamiana, on which the viruliferous larvae were feeding, was also confirmed at the molecular level, even though the characteristic symptoms of PSV infection were not observed. The results have shown that larvae of B. impatiens could acquire the virus and transmit it to healthy plants. Moreover, it has been proven that PSV might persist in the insect body transstadially. Although the molecular mechanisms of virion acquisition and retention during insect development need further studies, this is the first report on B. impatiens playing a potential role in plant virus transmission.

Download Full-text

Changes in Production Practices by Green Industry Growers from 2009 to 2019

Journal of Environmental Horticulture ◽

10.24266/0738-2898-39.3.123 ◽

2021 ◽

Vol 39 (3) ◽

pp. 123-130

Author(s):

Alicia L. Rihn ◽

Charles R. Hall ◽

Bryan J. Peterson ◽

Ariana P. Torres ◽

Marco A. Palma ◽

...

Keyword(s):

Integrated Pest Management ◽

Pest Management ◽

Firm Size ◽

Structural Changes ◽

Ornamental Plants ◽

Economic Recession ◽

Economic Losses ◽

Green Industry ◽

Levels Of Use ◽

Hand Weeding

Abstract As a result of the latest economic recession (2007 to 2009), the U.S. green industry suffered significant economic losses, leading to major industry structural changes. To be competitive and effectively manage risk, nursery and greenhouse operators need reliable and up-to-date information. However, the availability of such data from federal government sources has become limited. This report summarizes the state of the industry, focusing on trends in production-related characteristics from the 2009, 2014, and 2019 survey years. As firm size increased, the percent of annual sales attributed to large plant species (e.g., deciduous trees) increased, while herbaceous (e.g., perennials) and specialty (e.g., Christmas tree) plants made up a larger percentage of annual sales for small- and medium-sized firms. The majority of respondents (73.3%) indicated a proportion of their sales came from container-grown plants. The most frequently used integrated pest management (IPM) practice was removal of infested plants (81%), followed by cultivation/hand weeding. As firm size increased, participation in IPM strategies increased. Interestingly, statistical differences between small- and medium-sized firms were infrequent, indicating similar levels of use; however, most of the IPM strategies used were more frequently employed by large-sized firms when compared to small- or medium-sized firms. Index words: Container-grown, greenhouse, integrated pest management (IPM), nursery, ornamental plants.

Download Full-text

The diversity of fungi colonizing necrotic inflorescence buds of rhododendron (Rhododendron L.)

Acta Agrobotanica ◽

10.5586/aa.2013.025 ◽

2013 ◽

Vol 66 (2) ◽

pp. 79-84 ◽

Cited By ~ 1

Author(s):

Małgorzata Żołna ◽

Barbara Kierpiec-Baran ◽

Maria Kowalik

Keyword(s):

Dominant Species ◽

Trichoderma Viride ◽

Ornamental Plants ◽

Pathogenic Fungi ◽

Lower Number ◽

Botanical Species ◽

Fusarium Poae ◽

Identification Of Fungi ◽

Improved Cultivars ◽

Genetically Determined

The infection of rhododendron (Rhododendron L.) inflorescence buds caused by pathogenic fungi induces its browning, withering, and dieback. The identification of fungi causing the infection of rhododendron inflorescence buds can be a reason for creating new improved cultivars with genetically determined resistance to pathogens. The investigations were carried out in 2010–2011 on the collection of ornamental plants of the Faculty of Horticulture, University of Agriculture in Kraków. The material comprised infected inflorescence buds collected from nine newly bred taxa and one botanical species of rhododendron. 596 colonies of fungi belonging to 31 species were isolated from infected rhododendron inflorescence buds. The dominant species were: Pestalotiopsis sydowiana, Truncatella truncata, Alternaria alternata, Phialophora asteris, and Trichoderma viride, which constituted almost 74% of the isolated fungi population. Boeremia exigua var. exigua, Epicoccum nigrum, Fusarium poae, Mammaria echinobotryoides, Paraphoma chrysanthemicola, Phialophora cyclaminis, Phoma eupyrena, Talaromyces wortmannii, Umbelopsis isabellina, and other fungi were isolated in a lower number.The results of mycological analysis confirm the diversity of species colonizing necrotic inflorescence buds of rhododendron..

Download Full-text

ISOLATION, IDENTIFICATION AND CHARACTERIZATION OF BACTERIAL ANTAGONISTS OF THE DRAGON FRUIT FUNGAL PATHOGEN Neoscytalidium dimidiatum

Journal of Science and Technology - IUH ◽

10.46242/jst-iuh.v44i02.1036 ◽

2021 ◽

Vol 44 (02) ◽

Author(s):

NGUYEN NGOC AN ◽

HUA HUYNH MINH THAO ◽

HO NGUYEN HOANG YEN ◽

NGUYEN THI DIEU HANH ◽

NGUYEN LE HIEN HOA ◽

...

Keyword(s):

Fungal Pathogens ◽

Pathogenic Fungi ◽

Fungal Spore ◽

Stem Canker ◽

Antagonistic Effect ◽

Fruit Rot ◽

Economic Losses ◽

Neoscytalidium Dimidiatum ◽

Dragon Fruit

Dragon fruit or pitahaya (Hylocereus spp.) are famous for their nutrient-rich favourable taste, which brings high economic value to subtropical and tropical countries. However, dragon fruit cultivation all over the world is threatened by fungal pathogens and among them, Neoscytalidium dimidiatum has recently been shown to be responsible for stem canker and fruit rot which cause big economic losses. In order to find an environmentally friendly way to control this pathogen, five out of sixty-nine bacterial isolates used in a screening test for antifungal activity were selected. All five strains appeared to be aerobic Gram positive spore forming bacteria suggesting that they all belong to the Bacillus genus. Cell-free culture supernatants of these strains were found to strongly inhibit both fungal spore germination and mycelia growth in vitro for at least 5 days. The strain D19 which possessed the highest antagonistic effect was further identified to be Bacillus amyloliquefaciens, a well-known species shown to have antifungal effect against several other pathogenic fungi. Thus, the results of this study opened a new promising perspective to prevent Neoscytalidium dimidiatum infection during cultivation of dragon fruit.

Download Full-text

Five decades of research on phytoplasma-induced witches' broom diseases.

CAB Reviews Perspectives in Agriculture Veterinary Science Nutrition and Natural Resources ◽

10.1079/pavsnnr202116002 ◽

2021 ◽

Vol 16 (002) ◽

Author(s):

Chamran Hemmati

Keyword(s):

Plant Species ◽

Ornamental Plants ◽

Fruit Trees ◽

The Other ◽

Economic Losses ◽

Common Disease ◽

Vegetable Crops ◽

Management Options ◽

Disease Symptoms ◽

Broom Disease

Abstract Phytoplasmas, prokaryotic wall-less microorganisms, are important pathogens of several plant species in most parts of the world. Phytoplasmas have been reported associated with various symptoms on hundreds of plant species. Witches' broom disease (WBD) is one of the most common disease symptoms, which is caused by phytoplasma strains belonging to different phytoplasma groups. Symptoms of the disease differ from one host to the other as well as from one phytoplasma strain to the other. However, WBD symptoms are usually characterized by the production of a large number of small leaves, accompanied in some host plants by the production of several branches/shoots. Phytoplasma strains belonging to more than 13 groups and 39 subgroups have been reported associated with WBD in more than 116 plant species. Most of the phytoplasma strains causing WBD symptoms in plant species belong to the 16SrII and 16SrI groups, mainly 16SrII-D and 16SrI-B subgroups. The current review provides information on the different types of phytoplasma strains associated with WBD symptoms in ornamental plants, medicinal plants, forest trees, weeds, vegetable crops, field crops, and fruit trees. Emphasis is on WBD on acid limes, almonds, peanuts, jujube, and cassava that have resulted in significant economic losses in different countries. Description of the symptoms, phytoplasma groups, and management options is also provided for some of the diseases.

Download Full-text

Trichoderma harzianum Inoculation Reduces the Incidence of Clubroot Disease in Chinese Cabbage by Regulating the Rhizosphere Microbial Community

Microorganisms ◽

10.3390/microorganisms8091325 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1325

Author(s):

Junhui Li ◽

Joshua Philp ◽

Jishun Li ◽

Yanli Wei ◽

Hongmei Li ◽

...

Keyword(s):

Microbial Community ◽

Relative Abundance ◽

Chinese Cabbage ◽

Biological Control Agent ◽

Disease Incidence ◽

Pathogenic Fungi ◽

Economic Losses ◽

Vegetable Production ◽

Clubroot Disease ◽

Rhizosphere Microbial Community

Clubroot is a disease of cruciferous crops that causes significant economic losses to vegetable production worldwide. We applied high-throughput amplicon sequencing technology to quantify the effect of Trichodermaharzianum LTR-2 inoculation on the rhizosphere community of Chinese cabbage (Brassica rapa subsp. pekinensis cv. Jiaozhou) in a commercial production area. T. harzianum inoculation of cabbage reduced the incidence of clubroot disease by 45.4% (p < 0.05). The disease control efficacy (PDIDS) was 63%. This reduction in disease incidence and severity coincided with a drastic reduction in both the relative abundance of Plasmodiaphora brassicae, the causative pathogen of cabbage clubroot disease, and its copy number in rhizosphere soil. Pathogenic fungi Alternaria and Fusarium were also negatively associated with Trichoderma inoculation according to co-occurrence network analysis. Inoculation drastically reduced the relative abundance of the dominant bacterial genera Delftia and Pseudomonas, whilst increasing others including Bacillus. Our results demonstrate that T. harzianum LTR-2 is an effective biological control agent for cabbage clubroot, which acts through modulation of the soil and rhizosphere microbial community.

Download Full-text

In vitro and in vivo assessment of the potential of compost and its humic acid fraction to protect ornamental plants from soil-borne pathogenic fungi

Scientia Horticulturae ◽

10.1016/j.scienta.2009.05.030 ◽

2009 ◽

Vol 122 (3) ◽

pp. 432-439 ◽

Cited By ~ 19

Author(s):

Elisabetta Loffredo ◽

Nicola Senesi

Keyword(s):

Humic Acid ◽

Ornamental Plants ◽

Pathogenic Fungi ◽

Acid Fraction ◽

In Vivo Assessment

Download Full-text

Genotyping pathogenic strains of genus Xanthomonas causing bacterioses in a number of plants by DDSL technique

Biological Communications ◽

10.21638/spbu03.2019.302 ◽

2019 ◽

Vol 64 (3) ◽

Author(s):

Alexander Lazarev ◽

Valery Terletskiy ◽

Vladimir Chebotar

Keyword(s):

Molecular Genetic ◽

Ornamental Plants ◽

Complete Characterization ◽

Specific Pattern ◽

Economic Losses ◽

Dna Fragments ◽

Hereditary Material ◽

Bar Code ◽

Different Cultures

In the genus Xanthomonas, specialists consider a significant number of species and varieties (pathovars) of phytopathogenic bacteria that infect many agricultural and ornamental plants (about 400 species), which leads to serious economic losses. For the timely detection of these pathogens, accurate diagnosis is necessary, allowing correct and prompt identification. Molecular genetic methods are able to identify populations of Xanthomonas strains with a fairly complete characterization of their hereditary material. The proposed method of genotyping — double digest and selective label (DDSL) — is based on the use of two restriction endonucleases for the separation of bacterial genomic DNA. The DNA polymerase (Taq) present in the reaction mixture along with biotinylated deoxycytosine triphosphate (Bio–dCTP) allows for the visualization of DNA fragments. The tag only labels DNA fragments that have 3'-recessed ends formed by the first enzyme (BcuI). The second restriction endonuclease (Eco147I) produces blunt ends that are unable to incorporate the label. As a result, in the DDSL reaction, 20–50 clearly distinguishable DNA fragments are visualized on the filter. The number and distribution of fragments are characteristic for each bacterial strain of the genus Xanthomonas. Genotyping these microorganisms makes it possible to identify the specific profile of each strain, i.e., assign it a sort of “bar code” for individual specification. The strains of bacteria of the genus Xanthomonas, obtained from different species (tomato, radish, sorghum) are genetically separated from each other, showing a specific pattern in terms of the distribution of DNA fragments, despite the common geographical origin. A comparatively rare case of the identity of strains, despite their geographical and temporal unrelatedness and different cultures, has been recorded.

Download Full-text

An annotated list of ornamentals naturally found infected by Brevipalpus mite-transmitted viruses

Scientia Agricola ◽

10.1590/s0103-90162010000300014 ◽

2010 ◽

Vol 67 (3) ◽

pp. 348-371 ◽

Cited By ~ 43

Author(s):

Elliot Watanabe Kitajima ◽

José Carlos Verle Rodrigues ◽

Juliana Freitas-Astua

Keyword(s):

Ornamental Plants ◽

Single Species ◽

Ornamental Plant ◽

Economic Losses ◽

Food Crops ◽

Spot Virus ◽

Annotated List ◽

Green Spot ◽

Citrus Leprosis ◽

Cytoplasmic Type

The first cases of ornamental plants found infected by Brevipalpus transmitted viruses (BTV) were described in the 1990's from the region of Piracicaba, State of São Paulo, Brazil; subsequent cases were from other regions in the country and other American countries. Currently, 37 ornamental plant species (for the sake of simplicity, orchids being considered as a single species), belonging to 18 families of dicotyledons, have been reported hosting BTV. Because of the non systemic type of infection of these viruses, the localized diseases they cause are unimportant usually, but they have the potential to cause economic losses if severe outbreaks of Brevipalpus mite populations occur. Some ornamentals may serve as reservoirs to BTV known to cause serious damage to food crops as Citrus leprosis virus- cytoplasmic type (CiLV-C), passion fruit green spot virus (PFGSV) and Coffee ringspot virus (CoRSV).

Download Full-text

The effect of chitosan on limitation of growth and development of some pathogenic fungi for ornamental plants

Acta Agrobotanica ◽

10.5586/aa.2001.002 ◽

2013 ◽

Vol 54 (1) ◽

pp. 17-29 ◽

Cited By ~ 2

Author(s):

Alicja Saniewska

Keyword(s):

Fusarium Oxysporum ◽

Inhibitory Action ◽

Marked Effect ◽

Ornamental Plants ◽

Pathogenic Fungi ◽

Inhibitory Effect ◽

Crab Shell ◽

Necrotic Spots ◽

Tulip Bulbs

The inhibitory effect of crab-shell chitosan, medium (200-800 cps) and high molecular weight ( 800-2000 cps) (purchased from Sigma-Aldrich Chemicals) toward Alternaria alternata, Botrytis tulipae, Fiisarium oxysporum f. sp. callistephi, Fusarium oxysporum f. sp. tulipae, Phoma narcissi and Phoma poolensis was evaluated in vitro and in vivo. The chitosan evidently inhibited in vitro growth of all tested pathogens, with a marked effect at higher concentrations above 200 μg/cm3. Chitosan at a concentration of 1,25; 2,5 and 5,0 mg/cm3 didn't have inhibitory action in appearance of fungi growth on naturally contaminated Callistephus chinensis seeds. At the same concentrations, chitosan applied as bulb scales dressing of Hymenocallis narcissiflora bulbs, before inoculation or after inoculation with Phoma narcissi, inhibited the development of necrotic spots on scales. Chitosan used preventively or curatively at a concentrations of 1,25; 2,5 and 5,0 mg/cm3 indicated inhibitory effect on development of Fusarium oxysporum f. sp. tulipae on tulip bulbs. Chitosan at a concentration of 10 mg/cm3 applied preventively (first spray 12th June) was very effective in the control of Puccinia antirrhini on snapdragon in the field. The strongest inhibitory effect was observed on snapdragon treated 8 times at week intervals.

Download Full-text