Pathogenic fungi and Bio-control agents: Competitive bio-assay research

Fungi of the genus Trichoderma have a track record of being antagonist to quite of a number of agricultural important pathogens. Trichoderma have some unique characteristics that make it scientifically proven and suitable bio-control agents against varieties of pathogenic organism infecting economic food crops. Trichoderma has the advantage of being environment friendly and not hazardous to the health of human beings, livestock, soil and environment. Competitive bio-assay experiment was carried out in the laboratory on the effects of Trichoderma species (T. atroviride P1 isolates, T. harzianum T22 isolates, T. viride) on some crop pathogens (Phytophthora cinnanerium, Botrytis cinaria and Rhizoctonia solani). Pure culture of Trichoderma and pathogenic fungi were replicated four times and arranged in a complete block design. The result of the experiment shows that Trichoderma species are strong competitor of P. cinnanerium, B. cinaria and R.solani. Within 72 hours, the Trichoderma species were able to grow and completely overlap the P. cinnanerium, B. cinaria and R. solani. This strong competitiveness indicated that Trichoderma species would effectively inhibit the growth of P. cinnanerium, B. cinaria and R. solani on the infected crop; thus the application of Trichoderma species in the control of P. cinnanerium, B. cinaria and R. solani infected crops

Farmer evaluation of biocontrol methods against rootknot nematodes in tomatoes

This report was presented at the UK Organic Research 2002 Conference. Root-knot nematodes in tomatoes cause financial loss to Kenyan smallholders. While soil fumigation appears to be losing effectiveness two bio-control agents (bcas), Pasteuria penetrans and Verticillium chlamydosporium, appear promising. Participatory budgeting is being used to compare the bcas with chemical and other biological controls on commercial and organic smallholdings

The Economics of Biotechnology under Ecosystem Disruption

Economic analysis of chemical pesticide use has shown that the interactions between plants, pests, damage control technology and state of the ecosystem are important variables to be considered. Hence, a bio-economic model was developed for the assessment of Bt variety and pesticide-based control strategies of the cotton bollworm in China. The model simulates plant growth, the dynamics of pest populations and of natural enemies. The model predictions are used as major inputs for a stochastic partial budgeting procedure of alternative control strategies. Results show that: (1) productivity effects of Bt varieties and pesticide use depend on the action of natural control agents, and (2) the profitability of damage control measures increases with the severity of ecosystem disturbance. The findings highlight the importance of the choice of a counterfactual scenario in the assessment of the impact of agricultural biotechnology. Also, some doubts are raised whether the high benefits of Bt cotton varieties based on cross section comparisons are realistic.Research and Development/Tech Change/Emerging Technologies, Q57, Q55, O13, O3,

Theorizing surveillance in the UK crime control field

Drawing upon the work of Pierre Bourdieu and Loic Wacquant, this paper argues that the demise of the Keynesian Welfare State (KWS) and the rise of neo-liberal economic policies in the UK has placed new surveillance technologies at the centre of a reconfigured “crime control field” (Garland, 2001) designed to control the problem populations created by neo-liberal economic policies (Wacquant, 2009a). The paper also suggests that field theory could be usefully deployed in future research to explore how wider global trends or social forces, such as neo-liberalism or bio-power, are refracted through the crime control field in different national jurisdictions. We conclude by showing how this approach provides a bridge between society-wide analysis and micro-sociology by exploring how the operation of new surveillance technologies is mediated by the “habitus” of surveillance agents working in the crime control field and contested by surveillance subjects

Strategies for regulation of seed borne diseases in organic farming

The impact of seed borne diseases on organic cereal production in North-Western Europe is discussed as well as the potential of the possible control measures. It is concluded that it is essential for the organic seed production to put more focus on the control the seed borne diseases. Possible control measures exist, but only a few are used at present. Small seeds are statistically more infected by a number of seed borne diseases than larger seeds. Removal of these seeds by size and gravity separation could be used more frequently. Varieties resistant to the most significant seed borne diseases are available, and improved heat treatment techniques are being developed and are likely to be available for practice in the coming years. Some organic certifying bodies allow application of cupper-salts and bio-agents, but the use of these does to some extent conflict with the fundamental principles of organic diseases management

Influence of actinomycete isolates on cereal cyst nematode heterodera filipjevi juvenile motility

The effects of 126 actinomycete isolates were investigated in vitro on the motility of the second stage juveniles of the cereal cyst nematode, Heterodera filipjevi Madzhidow. Among them, isolate 3208 inhibited the motility of juveniles by 56.6% more than the negative control after one day of exposure. Motility inhibition reached 59.6% with isolate 3307 relative to the negative control after three days of exposure. All active actinomycete isolates were identified at the genus level as Streptomyces spp. Some of the isolates appear promising and worthy of further investigation for use as bio-control agents

Field performance of bio-primed seeds to suppress Colletotrichum truncatum causing damping-off and seedling stand of soybean.

The soybean is prone to be attacked by Colletotrichum truncatum at seed and seedling stages, resulting in pre- and post-emergence damping-off. The efficacy of bio-priming for the control of damping-off of soybean caused by C. truncatum and the final seedling stand using two fungal biocontrol agents (BCAs) Trichoderma harzianum and T. virens and one bacterial BCA Pseudomonas aeruginosa was evaluated under field conditions. Treatments consisted of chemo-primed with Benlate® as a positive control; bio-primed with P. aeruginosa; bio-primed with T. harzianum; bio-primed with T. virens; bio-primed with the mixture of T. virens and T. harzianum and the controls as hydro-primed and non-primed seeds. Trichoderma isolates used singly or as a mixture established on the seed surface with germinating hyphae, whereas the strain P. aeruginosa colonized profusely as determined by increased colony forming units (CFU) from 1.2 × 109 to 5.1 × 109 seed−1 after 12 h of bio-priming. All bio-priming treatments significantly reduced pre- and post-emergence damping-off relative to hydro- and non-primed seed controls. In general, bio-priming with P. aeruginosa was the most effective treatment for controlling pre and post-emergence damping-off, with reductions in disease incidence with increases ranging from 48.6% to 51.9% and 65.0% to 97.2%, respectively. Moreover, P. aeruginosa resulted in enhancement of seed germination and healthy seedling stand ranging from 32.4% to 60.0% and 56.0% to 73.9%, respectively. Bio-priming with T. harzianum reduced pre- and post-emergence damping-off by 42.8–46.8% and 35.0–85.1%, respectively. However, P. aeruginosa was generally comparable to T. harzianum and the fungicide Benlate®. The combination treatment of T. harzianum and T. virens produced compareable results to T. harzianum alone, and T. virens was the least effective of the bio-primed treatments. Bio-priming with P. aeruginosa or T. harzianum offered an effective biological seed treatment system and an alternative to the fungicide Benlate® for control of damping-off of soybean caused by C. truncatum of soybean

Management of early blight of potato using bio control agents and plant extracts

The early blight of potato is mainly controlled by using chemical fungicides but chemical fungicides have got some adverse effect on environment as well as human beings. Keeping this in mind an experiment was conducted to test the efficacy of four plant extracts (tea, garlic, onion and neem leaf extract) and four bio-control agents (Trichoderma viride, Pseudomonas fluorescence, Streptomyces graseoviridis and Bacillus substilis) in controlling early blight of potato under field and in in vitro condition. These antifungal compounds were applied 3 times at 7days interval after first appearance of the disease in the field. Among the bio control agents T. viride was found highly effective in per cent disease reduction (52.39%) of disease over control treatment. The tuber yield (25.51 t/ ha.) was also highest in this treatment compared to control treatment (19.53 t/ha). This was followed by treatment T2 i.e. P. fluorescens where per cent incidence and intensity of disease were (65.00%) and (19.10%) respectively with 38.97% reduction of disease over control with tuber yield 23.65 t/ha. It was followed by S. graseoviridis where per cent incidence and intensity of disease were (68.00%) and (22.90%) respectively with 26.30% reduction of disease over control with tuber yield 21.07 t/ha. Among plant extracts, only neem leaf extract exhibited per cent reduction of disease (33.18%) over control treatment in field condition and inhibition of radial growth (59.85%) and spore germination (81.95%) in in vitro condition. Therefore both T. viride and neem can be used for managing the early blight of potato