Identification of Pseudomonas fluorescens using different biochemical tests

Pseudomonas fluorescens not only enhances the plant growth but also controls the fungal pathogens by production of anti fungal metabolites. The objective of this experiment was to identify P. fluorescens using different biochemical tests. This research was carried out in Plant Pathology Laboratory at Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal. The result of this experiment indicated that P.  fluorescens gave positive result for Catalase test, Gelatin liquefaction, Fluorescent pigment and Oxidase test but negative result for starch hydrolysis test. The colony of P. fluorescens was maximum in maize seed than that of rice seed after two hours of inoculation, whereas higher number of colony was found in rice seed than that of maize seed after twenty four hours of seed inoculation. This findings is useful for identifying colony of P. fluorescens  per seed which is necessary for better seedling growth and effective biological control of pathogens

Bio-fertilizer activity of Trichoderma viride and Pseudomonas fluorescens as growth and yield promoter for maize

Saabunud / Received 01.06.2020 ; Aktsepteeritud / Accepted 16.09.2020 ; Avaldatud veebis / Published online 19.09.2020 ; Vastutav autor / Corresponding author: Bikram Nepali [email protected] bio-fertilizer potential of Trichoderma viride and Pseudomonas fluorescens on growth and yield performance of open-pollinated maize variety Rampur Composite was studied at the research farm of Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal during the winter season of 2018/19. The experiment was laid out in randomized complete block design with seven treatments (T1: recommended dose of NPK (120:60:40 kg NPK ha–1), T2: T. viride only, T3: P. fluorescens only, T4: T. viride + 50% NPK; T5: P. fluorescens + 50% NPK; T6: T. viride + P. fluorescens + 100 % NPK, T7: control) and replicated thrice. The package of agronomic practices was followed as per national recommendation. The result revealed that T. viride + 50% NPK enhanced most of the growth components like plant height (103%), leaf number (9.77%), stem diameter (73.98%), root length (40.57%), leaf area index (173.28%), leaf biomass (83.36%) and stem biomass (127.72%) of maize compared to the control. Similarly, the higher cob biomass (641 g), yield (5708 kg ha–1) and thousand kernel weight (295 g) were recorded in the plot applied to P. fluorescens + 50% NPK. The use of Trichoderma viride and Pseudomonas fluorescens with a half-dose of recommended fertilizers may increase the vegetative growth and yield of maize and may also help to reduce the rate of chemical fertilizers in maize

Efficacy of Various Biopesticides against Red Ant (Dorylus orientalis Westwood) in Potato Field

Red ant (Dorylus orientalis Westwood) is the most destructive insect pest of potato tubers in the field in Nepal. A field experiment was conducted at Bhatkada, Dadeldhura district, Nepal in 2020 to determine the efficacy of various biopesticides and chemical insecticide on red ants. The plot size in this experiment was 106.7 m2. Five treatments viz. Chlorpyriphos 20% EC (2 mL L-1 water), Banmaara (2 kg plot-1), Cow urine (2 L 6 L-1water plot-1), Agave (25 g tuber-1) and Control (no treatment) were evaluated in randomized complete block design with four replications. The data on plant height and the number of leaves were taken at 45, 60, and 75 days after planting (DAP). The data on slightly and severely infested tubers were taken after harvesting of potato. The results showed that Chlorpyriphos treated plots gave the lowest values of traits viz numbers of slightly infested tuber (91,500 ha-1), severely infested tubers (12,500 ha-1), weights of slight infested tubers (7,700 kg ha-1) and severely infested tuber (1,130 kg ha-1). Among the botanical pesticides, Agave treated plots provided the second lowest values of numbers of slightly infested tuber (145,500 ha-1), severely infested tubers (37,400 ha-1), weights of slight infested tubers (13,400 kg ha-1) and severely infested tuber (3,110 kg ha-1). The results showed that the Agave treatment provided the highest marketable yield (50,900 kg ha-1). Thus, Chlorpyriphos and Agave could be used to efficiently protect potato tubers from red ant in potato field

Identification of Pseudomonas fluorescens using different biochemical tests

Pseudomonas fluorescens not only enhances the plant growth but also controls the fungal pathogens by production of anti fungal metabolites. The objective of this experiment was to identify P. fluorescens using different biochemical tests. This research was carried out in Plant Pathology Laboratory at Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal. The result of this experiment indicated that P.  fluorescens gave positive result for Catalase test, Gelatin liquefaction, Fluorescent pigment and Oxidase test but negative result for starch hydrolysis test. The colony of P. fluorescens was maximum in maize seed than that of rice seed after two hours of inoculation, whereas higher number of colony was found in rice seed than that of maize seed after twenty four hours of seed inoculation. This findings is useful for identifying colony of P. fluorescens  per seed which is necessary for better seedling growth and effective biological control of pathogens