Fungal Pathogens of Navua sedge (Cyperus aromaticus) in equatorial Africa as prospective weed biological control agents

Author(s):  
Kunjithapatham Dhileepan ◽  
Paul Mutuku Musili ◽  
John Elia Ntandu ◽  
Emmanuel Chukwuma ◽  
Daisuke Kurose ◽  
...  
2005 ◽  
Vol 19 (1) ◽  
pp. 19-26 ◽  
Author(s):  
CAMILLA B. YANDOC ◽  
RAGHAVAN CHARUDATTAN ◽  
DONN G. SHILLING

2020 ◽  
Vol 30 (8) ◽  
pp. 855-861 ◽  
Author(s):  
Gregory S. Wheeler ◽  
Ellen C. Lake ◽  
Min B. Rayamajhi ◽  
Melissa C. Smith

2020 ◽  
Author(s):  
Senlin Liu ◽  
Muzammil Hassan Khan ◽  
Zhongyuan Yuan ◽  
Sarfraz Hussain ◽  
Hui Cao ◽  
...  

AbstractContinuous cropping always leads to severe abiotic and biotic problems, especially the high-intensity land utilization in greenhouses, which causes widespread concern. Effective Microorganisms (EM) and Bacillus subtilis (BS) have been widely used to promote plant growth and increase yields as biological control agents (BCAs). However, their effects on soil microbes are obscure. To regulate the microbial community in continuous cropping strawberry soils, we developed four soil amendments by combining EM and BS with compost. The amplicon sequencing of bacterial and fungal ribosomal markers was applied to study the response of the soil microbiome structure. We noticed a sharp increase in bacterial diversity after the addition of EM-treated high compost and BS-treated low compost, while there was no significant change in fungal diversity among treatments. Interestingly, both the relative abundance and FUNGuild predictions was consistent in revealing that BCAs may inhibit fungal pathogens in soils. Correlation analysis indicated that soil microbial community was indirectly driven by soil properties. Co-occurrence networks demonstrated that BCAs could be microecologically homogeneous through enhancing bacterial network complexity and modularity. Collectively, EM-treated high compost and BS-treated low compost can well regulate the microbial community structure and thus maintain soil health.


Author(s):  
Anahi A Barrera-López ◽  
Ariel W Guzmán-Franco ◽  
Materesa Santillán-Galicia ◽  
Fernando Tamayo-Mejía ◽  
Rafael Bujanos-Muñiz ◽  
...  

Abstract Bagrada hilaris Burmeister (Hemiptera: Pentatomidae) is a pest of Palearctic origin. Its presence in the United States was first reported in 2008 and in Mexico in 2014; it affects brassica crops. There are practically no reports of natural enemies of B. hilaris in America. Entomopathogenic fungi are strong candidates for microbial control of this pest. Evaluating the susceptibility of this pest to fungi that are native to the region where they will be used is a sensible first step to finding candidate biological control agents. The aim of our research was to select potential microbial agents to control B. hilaris. Eleven isolates of Beauveria bassiana, Beauveria pseudobassiana, Metarhizium anisopliae, and Isaria fumosorosea were evaluated to determine the susceptibility of B. hilaris. Isolates of B. bassiana caused the highest mortality due to infection (100%) compared with the other isolates. The I. fumosorosea isolate caused the lowest percent mortality (56%). The two B. bassiana isolates Bb88 and AP3 were more virulent than M. anisopliae isolate Ma129. The sex of the insect had no effect on infection levels achieved by B. bassiana isolates Bb88 and AP3. The results of our study contribute valuable information for the development of fungal species with potential to manage B. hilaris populations. Field studies are the next step in order to develop these isolates as biological control agents of B. hilaris.


Author(s):  
Martin P. Hill ◽  
Julie A. Coetzee

Abstract Classical biological control has been used as a management tool for invasive non-native plant species globally for over 200 years. There have been some very successful programmes, most notably on waterweeds, cacti and seed reduction in perennial trees. Seventy per cent of agents released have established in at least one instance, and 66% of the targeted invasive species have showed some level of control. However, some programmes have failed to meet expectations, for example on Lantana camara. The most commonly cited reasons for the failure of establishment or limited efficacy of biological control agents are unsuitable climatic conditions and genotype incompatibility. We propose that antagonistic biotic interactions play a significant role in the outcomes of weed biological control programmes. Induced plant defences (physical and chemical) that can be mounted rapidly by the invasive non-native plants can result in the reduction in agent populations after initial attack. Rapid induction of plant defences have been implicated in the lack of long-term establishment of the agent Falconia intermedia that showed great initial promise against the widespread invasive shrub L. camara. Host range expansion by native natural enemies onto biological control agents have also been shown to reduce population growth of agents. Finally, competition from indigenous plant species aids invasive alien plant population reduction in the presence of herbivory. All three factors have been poorly studied and further work is needed to better explain the outcomes of weed biological control programmes.


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