Production of Papaya Seedlings Using Spirulina platensis as a Biostimulant Applied on Leaf and Root

Aims: This study evaluates the influence of Spirulina platensis concentrations on the growth and quality of papaya (Formosa Group) ‘Tainung-1’.

Study Design: The experimental design was completely randomised, with plots subdivided over time.

Place and Duration of Study: From April to June 2017, two greenhouse experiments were carried out at the Agro-Food Science and Technology Center of the Federal University of Campina Grande, Pombal-PB, Brazil.

Methodology: We carried out two greenhouse experiments in completely randomised designs, one with the application of S. platensis on the leaf and other with an application on the root. In both experiments, the treatments consisted of six biomass concentrations of S. platensis (0.0, 0.4, 0.8, 1.2, 1.6, 2.0%).

Results: At 52 days after sowing, we measured the following variables: growth, production of dry and fresh mass of roots and shoot, and the seedlings quality index. The modelling functions predict that the suspensions with 1.08% of S. platensis applied on root may provide the best growth and biomass production of the seedlings. However, suspensions of S. platensis applied on leaf were inefficient in the improvement of seedling quality.

Conclusion: When applied to the roots, a suspension of 1.08% S. platensis increases the growth and biomass production of the seedlings; and when used in the concentration of 0.88% improves the quality of the 'Formosa' papaya seedlings. Suspensions of S. platensis applied on leaves do not affect the growth and quality of seedlings of papaya.