Pruning of the aerial part in tall sour passion fruit seedlings aiming at seedling quality and reproductive precocity

Abstract

Biotic and abiotic stresses limit the growth, development, and production of sour passion fruit plants. The use of taller seedlings can reduce the vulnerability of the crop, as can cultivation in protected environments. However, due to the long period seedlings spend in the nursery, coupled with their continuous and indefinite growth, it is necessary to establish proper management to balance the growth of the aerial parts and the roots. Thus, the objective was to evaluate the effect of apical pruning of the aerial parts during the seedling formation phase, quantifying changes in the morphophysiology and reproductive cycle of plants grown both in a protected environment and in the open field. The treatments consisted of: control (T1), pruning after the emergence of the 4th, 7th, 9th, and 11th leaves (T2); 7th, 10th, 12th, and 14th leaves (T3); 10th, 13th, and 15th leaves (T4); and 7th oldest leaf, 10th, and 12th leaves (T5). During the seedling growth phase, all treatments with pruning management showed a greater stem diameter, exceeding 37 % compared to the control. Overall, when analyzing morphological and physiological parameters, treatment T3 stood out compared to the control. However, in the reproductive phase of the plant, both in open field and protected environments, treatments T2 and T4 showed over a 40 % increase in the flowering speed index compared to the control. These results impacted the higher harvest speed index in the first 40 days. However, these changes did not affect production and productivity, nor subsequent harvests.