Production of a potential liquid plant bio-stimulant by immobilized Piriformospora indica in repeated-batch fermentation process

Piriformospora indica, a mycorrhizal-like fungus able to establish associations with roots of a wide range of plants, supporting plant nutrition and increasing plant resistance and tolerance to stress, was shown to solubilise phosphate applied in the form of animal bone char (HABO) in fermentation systems. The process of P solubilisation was caused most likely by proton extrusion and medium pH lowering. The fungal mycelium was successfully immobilized/retained in a polyurethane foam carrier. Further employment of the immobilized mycelium in repeated-batch fermentation process resulted in at least 5 cycles of P solubilization. The concentration of soluble P increased during the experiment with 1.0 and 3.0 g HABO l−1 and at the end of the 5th batch cycle reached 40.8 and 120 mg l−1, respectively. The resulting final liquid product, without or with solubilized phosphate, was found to significantly increase plant growth and P plant uptake. It can be used as a biostimulant containing microbial plant growth-promoting substances and soluble P derived from renewable sources (HABO) thus supporting the development of sustainable agro-ecosystems.This work was supported by Project CTM2014-53186-R, Ministerio de Economia y Competitividad-ES/EC FEDER Fund and the sabbatical Grant PRX16/00277 to NV

Comparative Analysis of the Effect of Different Insecticide Treatments on Nagpur Mandarin in Biomass Accumulation

The Comparative Analysis of the Effect of Different Insecticide Treatments in Nagpur Mandarin on Biomass Accumulation was conducted during the Ambia bahar of 2009-10. The experiment was carried out on an eight-year-old Nagpur mandarin orchard with a spacing of 6.0 m x 6.0 m at Futala farm, College of Agriculture, Nagpur. The study aimed to assess the impact of different insecticide treatments on Citrus psylla management. A trial comprising of eleven treatments was set in the Randomized Block Design (RBD), replicated thrice, with each treatment plot having four plants. Four branches were selected from each plant at random and tagged. The population of citrus psylla (both nymph and adult) was counted on the twigs of 5 cm fresh growth of the shoot from all the four sides of the plant during Ambia bahar of 2009-2010. The study found that imidacloprid 0.25 ml/l, acetamiprid 0.1 g/l, and quinalphos 1 ml/l + karanj oil (pongamia oil) 10 ml/l were the most effective treatments based on biomass accumulation (wet weight basis). Meanwhile, treatments with lower efficacy were Verticillium lecani 4 g/l + mineral oil 5 ml/l, azadirachtin 2 ml/l, mineral oil 5 ml/l, and Verticillium lecani 4 g/l. Furthermore, the application of imidacloprid 0.25 ml/l, acetamiprid 0.1 g/l, thiomethoxam 0.1 g/l, and quinalphos 1 ml/l + karanj oil (pongamia oil) 10 ml/l were found to be the most effective treatments based on biomass accumulation on a dry weight basis. The results indicated that treatments with imidacloprid, acetamiprid, thiomethoxam, and quinalphos with karanj oil were the most effective in promoting higher growth of new flush, bearing (buds, flowers and fruit), and biomass accumulation on both wet weight and dry weight basis. Among them, the treatment with imidacloprid at 0.25 ml/l was found to be the most effective