Potencial da microalga Desmodesmus sp. como biofertilizante em Feijão Pérola

Abstract

Microalgae are a source of some macro- and micronutrients, phytohormones, lipids, carbohydrates, and other molecules; due to their excellent adaptive capacity to the most diverse environments, they gained prominence in the biofertilizer industry. Thus, the objective of this work was to evaluate the potential efficiency of the microalgae Desmodesmus sp. L2B Bold as biofertilizer in common beans (Phaseolus vulgaris L.) cv. BRS Pearl. The microalgae culture was performed using a BG-11 medium, at room temperature, with a 12-hour photoperiod for 5 days. Microalgae biomass was applied to common bean by manual irrigation with a population of 107 cells mL-1, for the control treatment water was used. The application was started 15 days after sowing, then every 10 days thereafter. As for agronomic parameters, the total number of vegetables and grains, a total dry mass, root dry mass, fresh and dry mass of leaves were positively influenced by microalgae. Regarding leaf pigments, there was a significant increase of approximately 30% in chlorophyll a and b content with the application of biofertilizer 17 days after sowing (DAS), and 7% in the middle of the cultivation cycle (37 DAS). As for foliar enzymatic activity, there was a significant increase in Superoxide dismutase (SOD) with the application of biofertilizer in all periods of cultivation, when compared to the control group. Phenylalanine ammonia-lyase (PAL) initially presented significantly lower results when the biofertilizer was applied. However, throughout the cycle, the result was reversed, with the amount of PAL being around 120% to 1500% higher in fertilized plants in the middle and at the end of the cycle, respectively. It is concluded that the microalgae Desmodesmus sp. L2B Bold has great potential for use as a biofertilizer in the cultivation of common beans (Phaseolus vulgaris L.) cv. BRS Pearl.