Biological treatments for quality improvement and production of Aloe vera gel

Abstract

Research goal: The aim of this work was to develop a sustainable and innovative organic cultivation protocol, usable by local Italian companies, based on the use of microbial biostimulants (beneficial bacteria and fungi, arbuscular mycorrhizae and algae) able to improve the growth and quality production of the medicinal gel of Aloe vera.

Materials and Methods: The experiments, started in December 2020, were conducted in the greenhouses of CREA-OF in Pescia (Pt), Tuscany, Italy (43°54′N 10°41′E) on Aloe vera (4 year old plants). The experimental groups were: i) group control, irrigated with water and substrate previously fertilized; ii) group with Effective microorganisms irrigated with water and substrate previously fertilized; iii) group with Trichoderma spp. irrigated with water and substrate previously fertilized; iv) group with arbuscular mycorrhizae irrigated with water and substrate previously fertilized; v) group with Ascophyllum nodosum irrigated with water and substrate previously fertilized.

Results and Discussion: The experiment showed a significant improvement in agronomic parameters and physical, chemical and microbiological characteristics analysed on plants treated with microbial and algae-based biofertilizers. In particular, there was a significant improvement in the number of leaves per plant, new shoots, fresh vegetative weight, root and gel weight and the inflorescences number. On the leaves of the treated theses, there was a significant increase in leaf length and width and an improvement in gel pureness (optical density). There was also an increase in the number of microorganisms in the treated substrates and a lowering of the pH of the growing medium. The test also showed a lowering of the pH of the gel and a significant increase in soluble solids, sugars and fiber content in the theses inoculated with Effective microorganisms and a significant increase in fructose, glucose, proline and aloin.

Conclusions: The trial confirms the significant results already obtained in other trials on vegetable, ornamental and Aloe plants by applying biofertilizing microorganisms and algae. The aim of this work was to develop an organic cultivation protocol based on microbial and algae treatments that can be used to improve the quality of Aloe vera plants. This protocol can be applied in general by those companies that are dedicated to the production of ornamental and fruit cacti and succulents and want to reduce or even eliminate the use of plant protection products.