Biocontrol of seed-borne Alternaria raphani and A. brassicicola

1987 ◽  
Vol 33 (10) ◽  
pp. 850-856 ◽  
Author(s):  
G. Vannacci ◽  
G. E. Harman
Keyword(s):  
Biological Control ◽  
Host Range ◽  
Trichoderma Harzianum ◽  
Pythium Species ◽  
Biological Control Agents ◽  
Fusarium Sp ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Radish Seedlings

Forty-two microorganisms were tested as biological control agents against Alternaria raphani and A. brassicicola. Tests were conducted for in vitro antagonistic ability, for ability to control the pathogens on naturally infected seeds germinated on moistened blotters, and in planting mix in growth chamber studies, and for their ability to reduce pod infection. The organisms tested were obtained from cruciferous seeds or were strains already identified as being effective against soil-borne Pythium species. The blotter test indicated that six organisms increased both the number of healthy seedlings and the number of seedlings produced from A. raphani infected radish seeds. An additional seven strains improved either germination or increased the number of healthy seedlings. Twenty-nine organisms increased the number of healthy cabbage seedlings from A. brassicicola infected seeds, but total germination was not modified by any treatment. Experiments in planting mix showed that five antagonists (Chaetomium globosum, two strains of Trichoderma harzianum, T. koningii, and Fusarium sp.) increased the number of healthy plants in both radish samples tested, while four additional antagonists provided a significant increase in only one of the samples tested. The five antagonists that consistently increased numbers of healthy radish seedlings also decreased pod infection by A. raphani. None were as effective as iprodrone, however. Several effective antagonists were found to be mycoparasitic against Alternaria spp. Some strains of Trichoderma previously found to be effective against Pythium spp. were also effective against Alternaria spp., indicating that these strains have a wide host range.

scholarly journals Management of Xanthomonas Leaf Blight of Onion with a Plant Activator, Biological Control Agents, and Copper Bactericides

Plant Disease ◽  
2005 ◽  
Vol 89 (6) ◽  
pp. 631-639 ◽  
Author(s):  
David H. Gent ◽  
Howard F. Schwartz
Keyword(s):  
Biological Control ◽  
Field Experiments ◽  
Leaf Blight ◽  
Disease Suppression ◽  
Biological Control Agents ◽  
Copper Hydroxide ◽  
In Planta ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Bulb Yield

Xanthomonas leaf blight (Xanthomonas axonopodis pv. allii) is a yield-limiting disease of onion (Allium cepa) in the western United States. Frequent applications of copper-based bactericides amended with an ethylenebisdithiocarbamate fungicide (e.g., maneb or mancozeb, class B2 carcinogens) provide some disease suppression, but strategies to reduce conventional bactericide use are needed to minimize grower costs, environmental impact, and public exposure to class B2 pesticides. Applications of acibenzolar-S-methyl reduced in planta and epiphytic populations of X. axonopodis pv. allii as effectively as applications of copper hydroxide-mancozeb in growth chamber studies. Under field conditions, four weekly applications of acibenzolar-S-methyl reduced severity of Xanthomonas leaf blight as or more effectively than 9 to 12 weekly applications of copper hydroxide or copper hydroxide-mancozeb. Acibenzolar-S-methyl applications did not increase bulb yield or grade compared with copper bactericide treatments. However, bulb yield was reduced 22 to 27% when 10 weekly applications of acibenzolar-S-methyl were made in the absence of disease. Application of a commercial formulation of both Pantoea agglomerans strain C9-1 and Pseudomonas fluorescens strain A506 reduced severity of Xanthomonas leaf blight in field experiments. Weekly copper hydroxide applications starting 1 to 2 weeks before bulb initiation were as effective as weekly applications started 3 to 4 weeks before bulb initiation, irrespective of the maneb rate used. Integration of acibenzolar-S-methyl and biological control agents with copper hydroxide in a carefully timed spray program may eliminate the use of the class B2 carcinogens maneb and mancozeb on onion without compromising efficacy for management of Xanthomonas leaf blight.

scholarly journals Daily Indexes for Predation and Growth of Nematophagous Mushrooms Species of Hohenbuehelia (Pleurotaceae) on Panagrellus redividus

2018 ◽  
Vol 10 (3) ◽  
pp. 276
Author(s):  
Cleonice Lubian ◽  
Danielle Dutra Martinha ◽  
Roberto Luis Portz ◽  
Alexandre Gonçalves dos Santos e Silva Filho ◽  
Vagner Gularte Cortez ◽  
...  
Keyword(s):  
Biological Control ◽  
Growth Speed ◽  
Test Evaluation ◽  
Biological Control Agents ◽  
Panagrellus Redivivus ◽  
Mycelia Growth ◽  
Living Organisms

Biological control is a method of controlling pests through the use of other living organisms. The purposes of this study were to test Hohenbuehelia species as biological control agents against Panagrellus redivivus in vitro, evaluating nematodes influence on mycelia growth; establishing daily indexes for predation and growth and setting predation percentage. Five species previously identified as 436-Hohenbuehelia mastrucata (Nematoctonus hamatus), 528-H. bullulifera (not described so far), 581-H. paraguayensis (N. sp.), 582-H. sp. (N. sp.) and 631-H. portegna (N. campylosporus) were submitted to anamorphic purification directly from basidioma. Afterwards, 100 nematodes were added to each pure colony for predation test. Evaluation started right after 24 hours of nematode-fungus interaction. Immobilized and/or penetrated nematodes were counted and mycelia growth was measured. Results were subjected to variance analyses. Hohenbuehelia mastrucata had the best performance in growth speed, followed by H. portegna and H. paraguayensis; Nematodes multiplyied much but none specie grew more as an influence of their movement under mycelium, however all species formed trap devices and some of them produced adhesive or repelent substances. Trap devices were formed in control plates also. The plates of H. paraguayensis without nematodes grew more than treatments. Cumulative predation of H. portegna was the highest at 24 (195.5%) and 48 hours (235%). At the last evaluation day, H. paraguayensis preyed the same amount (185.75%) than H. portegna, followed by H. mastrucata (109.51%). Resulst of predation daily indexes displayed chronological activity for each isolate, where H. portegna was very reactive at first 24 hours, H. mastrucata raised its predacious activity in 48 hours being constant from this time on and H. paraguayensis pointed out itself at 72 hours. Other species presented low predation and growth indexes throughout experiment.

scholarly journals In vitro and in vivo Assay for Assessment of the Biological Control Potential of Streptomyces sp. KT

2017 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Tatsuya Ohike ◽  
Minori Maeda ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
...  
Keyword(s):  
Biological Control ◽  
Suppressive Effect ◽  
Phytopathogenic Fungi ◽  
Dual Culture ◽  
Biological Control Agents ◽  
Bipolaris Oryzae ◽  
Biological Control Potential ◽  
Dual Culture Assay

Rhizoctonia solani is fungal plant pathogen that infects many different host plants. Recently, biological control agents that are friendly to the environment and ecosystems have attracted much attention as an alternative to the use of chemical fungicide which have been used worldwide to control soil borne pathogens including R. solani. In this study, 53 strains of actinomycetes isolated from environmental soils, and antifungal activities of them were assessed by the dual culture assay. Strain KT showed strong inhibitory activities against 8 phytopathogenic fungi. A great suppressive effect on R. solani growth was observed in the inoculation test of plants using cucumber and chin-geng-sai. In addition, infection of Bipolaris oryzae also could be suppressed in the detached leaf assay using oats. As a result of genetic analysis, it was shown that KT was a species closely related to Streptomyces lavenduligriseus NRRL B-3173T. However, as far as we know, there is no report for biological control agents using S. lavenduligriseus. This study suggests that the strain KT may useful as biological control agents to suppress various crop diseases.

scholarly journals Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic condition

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
SUPRIYANTO ◽  
PURWANTO ◽  
S.H. POROMARTO ◽  
SUPYANI
Keyword(s):  
Biological Control ◽  
Antagonistic Activity ◽  
Biological Control Agents ◽  
Antagonistic Fungi ◽  
High Incidence ◽  
Acidic Conditions ◽  
Mineral Soils ◽  
Ph Range ◽  
Biological Methods

Abstract. Supriyanto, Purwanto, Poromarto SH, Supyani. 2020. Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic conditions. Biodiversitas 21: 2935-2945. The use of peatlands is a significant contributor to the world’s palm oil production. A serious problem of oil palm plantations in peatlands is the high incidence of basal stem rot (BSR) disease caused by Ganoderma, which has a higher attack rate than on mineral soils. There is no effective way to control Ganoderma in peatlands. At present, the effort for the same focuses on environment-friendly biological methods; however, this is constrained by the unavailability of appropriate biological agents for peatlands. The development of biological control agents for peatlands is hampered by limited data on biological control of Ganoderma in peatlands. This research was conducted to evaluate the in vitro antagonistic activity of fungi isolated from a peatland in acidic pH conditions. Twenty-seven Ganoderma-antagonistic fungi from peatland were evaluated for their activity and their ability to antagonism in vitro within a pH range of 2-7. The results show that most antagonistic fungi from peatland, based on biomass weight, the sporulation ability, and germination of conidium, were able to grow optimally at pH 3.0-4.0, indicating that most of the Ganoderma-antagonistic fungi from peatland can be used as biological control agents for BSR on oil palms in peatlands.

scholarly journals The Biology of Casmara subagronoma (Lepidoptera: Oecophoridae), a Stem-Boring Moth of Rhodomyrtus tomentosa (Myrtaceae): Descriptions of the Previously Unknown Adult Female and Immature Stages, and Its Potential as a Biological Control Candidate

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 653
Author(s):  
Susan A. Wineriter-Wright ◽  
Melissa C. Smith ◽  
Mark A. Metz ◽  
Jeffrey R. Makinson ◽  
Bradley T. Brown ◽  
...  
Keyword(s):  
Biological Control ◽  
Host Range ◽  
Stem Borer ◽  
South Florida ◽  
Immature Stages ◽  
Myrtus Communis ◽  
Biological Control Agents ◽  
Perennial Shrub ◽  
Original Species ◽  
Rhodomyrtus Tomentosa

Rhodomyrtus tomentosa is a perennial shrub native to Southeast Asia and is invasive in South Florida and Hawai’i, USA. During surveys of R. tomentosa in Hong Kong from 2013–2018 for potential biological control agents, we collected larvae of the stem borer, Casmara subagronoma. Larvae were shipped in stems to a USDA-ARS quarantine facility where they were reared and subjected to biology studies and preliminary host range examinations. Casmara subagronoma is the most recent Casmara species to be described from males collected in Vietnam and Indonesia. Because the original species description was based on only two male specimens, we also provide a detailed description of the female, egg, larva, and pupa. Finally, we conducted preliminary host range trials utilizing Myrtus communis, Myrcianthes fragrans, and Camellia sinensis. Casmara subagronoma emerged from M. fragrans, a Florida-native shrub, and larvae were able to survive in non-target stems for over a year (>400 days). Based on these findings and difficulty in rearing, we do not believe C. subagronoma is a suitable insect for biological control of R. tomentosa at this time, but may warrant further study. This investigation also illustrates the importance of host surveys for conservation and taxonomic purposes.

scholarly journals Non-Synergistic Effect of Trichoderma harzianum and Glomus spp. in Reducing Infection of Fusarium Wilt in Banana

Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 43 ◽  
Author(s):  
Arfe Castillo ◽  
Cecirly Puig ◽  
Christian Cumagun
Keyword(s):  
Biological Control ◽  
Synergistic Effect ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Trichoderma Harzianum ◽  
Root Weight ◽  
Biological Control Agents ◽  
Competitive Effects ◽  
Glomus Spp ◽  
Race 4

Philippine banana is currently threatened by Fusarium oxysporum f. sp. cubense Tropical Race 4 (FocR4). This study investigated the use of Trichoderma harzianum pre-treated with Glomus spp, as a means of managing Fusarium wilt on young ‘Lakatan’ banana seedlings. Results showed that Glomus applied basally significantly improved banana seedling growth with increased increment in plant height and pseudostem diameter and heavier root weight. The application of Glomus spp. alone offered 100% protection to the ‘Lakatan’ seedlings against FocR4 as indicated by the absence of the wilting symptom. A combination of T. harzianum and Glomus spp. also gave significant effect against Fusarium wilt through delayed disease progression in the seedlings but was not synergistic. Competitive effects were suspected when application of the two biological control agents on banana roots was done simultaneously.

The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

1999 ◽  
Vol 50 (8) ◽  
pp. 1469 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden ◽  
G. M. Murray
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Rhizobium Trifolii ◽  
Biological Control Agents ◽  
Control Activity ◽  
Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

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