Use and evaluation of new organic fertilizers in the cultivation of Abelmoschus esculenthus (Okra)

Abstract

Research objective: The objective of this work was to evaluate the properties and effect of certain organic fertilizers that can be used in organic farming in comparison with fertilizers of inorganic origin on Abelmoschus esculenthus plants. In addition, the interactions that can develop with microorganisms in the rhizosphere and the possible beneficial effects on transplant stress, nutrient uptake by roots and reduction of plant mortality were investigated. Materials and Methods: The experiments, which began in May 2022, were conducted in the greenhouses of CREA-OF in Pescia on plants placed in pots 12 cm in diameter and on which fertilizers of organic and inorganic origin were evaluated. In September 2022, plant height, number of leaves, leaf surface area, vegetative weight, root volume, root length, seeds per plant, number, weight, girth and length of pods, total substrate bacteria, substrate pH and number of dead plants were analysed. Results and Discussion: The experiment showed that the application of organic nitrogen and potassium fertilizers can significantly improve the quality and yield of Abelmoschus esculenthus plants. In general, a significant increase in height and vegetative and root growth of the plants was observed, especially in nitrogen and potassium synthesis, with an improvement also in the number of fruits and seeds per plant. Plant mortality also decreased significantly compared to the control with synthetic fertilizers, and microbial colonisation of the substrate increased, which probably affected the plants by influencing both vegetative and root growth and defence against biotic stressors. Conclusions: Organic fertiliser trials showed that these products can significantly improve plant growth by positively affecting the soil microbial component. This is an additional opportunity, especially for those farmers who not only seek to reduce the use of synthetic fertilizers, but also want to use sustainable techniques that better preserve plants and soils, while guaranteeing the production of quality products.

Use of marine minerals obtained through an innovative process with added silver for the cultivation and protection of Solanum lycopersicum

“…Furthermore, it resulted in a significant increase in microfauna in the substrates treated without silver, an effect probably influenced by all the mineral and organic substances present in the seawater. Also of interest was the increase in leaf LAI and root development, an effect probably influenced by the microbial activity in the soil, which not only increased root development, but also led to increased nutrient uptake, as found in previous trials by the same author [30]. The presence of molecules such as silver significantly reduced the mortality of the treated seedlings, probably acting on the intrinsic stimulation of the plant's defences and not directly on biotic stresses (in the treated theses, in fact, the soil microbial biomass increased) [31,32,33].…”

Sea minerals and marine recycled water use obtained through an innovative extraction process for the cultivation of Impatiens glandulifera and Helianthus annuus

“…The surface of the slide is etched with a grid of squares, with the area of each square known. Determination of viable microbial load after serial decimal dilutions, spatula seeding (1 ml) and plate counting after incubation [25];…”