Effect of urea, zinc sulphate and boric acid on yellow passion fruit seedling development

Abstract

This research was conducted with the objective of verifying the effect of urea, zinc sulphate and boric acid on the passion fruit (Passiflora edulis f. flavicarpa Deneger) seedling development. The experiment was installed in one of the seedling nurseries of ESACMA, at Machado, MG, Brazil. The experimental design used was a three-replicate completely randomized one, with a 4 x 3 x 3 factorial combination of the following treatments: four levels of urea (0.0; 1.5; 3.0 and 4.5%); three levels of zinc sulphate (0.0; 1.0 and 2.0%) and three levels of boric acid (0.0; 1.0 and 2.0%), applied to the experimental units, each comprising nine seedlings. Seventy days after sowing, the seedlings were removed so that the assessments of the growth characteristics could be performed. Increasing levels of urea (1.5; 3.0 and 4.5%) promoted increments in the values of the growth characteristics, when compared with the untreated control. Increasing the levels of zinc sulphate (1.0 and 2.0%) and boric acid (1.0 and 2.0%) however, caused decreases in the values of the growth characteristics, in comparison with the untreated control.