Economic feasibility of Gluconacetobacter diazotrophicus in carrot cultivation

Nelson Ceballos-Aguirre,Alejandro Hurtado-Salazar,Óscar Julián Sánchez,Jorge Andrés Cuellar,Gloria María Restrepo

doi:10.1590/0034-737x202269010006

Abstract

The inclusion of more sustainable alternatives such as bacterial inoculants is a viable option for the competitiveness of vegetable crops in tropical countries such as Colombia. The economic feasibility of a bacterial suspension of G. diazotrophicus applied to the carrot crop was determined. The native isolate G. diazotrophicus GIBI029 was evaluated and the strain ATCC 49037 was used as a control. The experiment was installed in a subdivided plot design, where the plot was the bacterium G. diazotrophicus (ATCC49037 and GIBI029. The subplot was the concentration of G. diazotrophicus (88×106 CFU/mL and 18×107 CFU/mL) and, in it, the levels of nitrogen and phosphorus (0% and 100% nitrogen and phosphorus) were assorted. The average weight of the carrot (g) and the yield by quality of the consuming organ (kg/ha) were evaluated. Through the production cycle, fixed, variable, and total costs were calculated. Benefit / cost ratios higher than 1.46 and net income up to US$ 10,817/ha were achieved. It is possible to efficiently and economically use the native isolate G. diazotrophicus GIBI029 in the search for more sustainable and competitive cultural practices.

Highlights

The carrot is one of the most consumed vegetables worldwide
The largest plot was made up of the bacterium G. diazotrophicus (ATCC49037 strain and GIBI029 isolate), and the following bacterial concentrations were arranged in the subplots: 88×106 CFU/mL and 18×107 CFU/mL (Restrepo, 2014)
The application of the high level of concentration (d2 =18x107 CFU/mL) of the evaluated bacterial suspensions showed yields higher than 30,345 kg/ha, as in the case of treatment with the standard ATCC strain with 100 % fertilization that was above the absolute control without the addition of nitrogenous and phosphorous fertilizers (Control-0NP) and the commercial control to which was applied 100% of this type of fertilization (Control-100NP)

Summary

Introduction

The carrot is one of the most consumed vegetables worldwide. The world production of carrots reached 39,996,287 t in 2018, corresponding to a total cultivated area of 1,131,049 ha (Faostat, 2020). Carrot production in Colombia is very expensive due to the high price of fertilizers: approximately 25% of the total costs are destined to the nutrition of the crop. In the case of carrot cultivation, the Colombian farmer cannot compete with foreign producers, since imports of this vegetable present reduced purchase charges and have low product distribution tariffs. The Colombian agricultural sector is unaware of the use of new, cheaper fertilization strategies such as the use of biofertilizers, which could affect the final marketing price. The development of biofertilizers traditionally focused on the production of Rhizobium for its application in legume crops, especially soybeans; other alternatives are currently being explored through the development of inoculants based on autochthonous nitrogen-fixing bacteria such as those of the genera Herbaspirillum and Gluconacetobacter

Methods

Results

Conclusion