Seedlings production of Gomphrena globosaand Petunia x hybridain different times and substrates

Abstract

This study aimed to evaluate the seedlings growth of Petunia x hybridaand Gomphrena globosaat different times and substrates based on agricultural residues. A completely randomized experimental design was adopted, in a factorial scheme, with treatments consisting of four replications and the experimental unit formed by ten plants. The flower species Petunia x hybridaand G. globosawere cultivated in five substrate compositions and in two seasons, with sowing carried out in April and June for Petunia x hybridaand April and October for G. globosa. The substrates were composed using commercial substrate (CM), bovine manure (BM), worm humus (WM) and rice husk ash (HA), in volumetric proportions: (S1) 100% CS; (S2) 40% CS + 20% BM + 20% WH + 20% HA; (S3) 60% CS + 20% WH + 20% HA; (S4) 60% CS + 20% BM + 20% HA; and (S5) 80% CS + 20% BM. Emergence, emergence speed index, height, number of leaves, length of the largest leaf, length of the largest root, dry mass of the aboveground part, dry mass of the root system and total dry mass were evaluated. The seedlings growth of the Petunia x hybridaand G. globosachanged according to the characteristics of the substrates and the growing seasons. The substrate composed with 80% commercial substrate and 20% bovine manure showed similar or superior results to the commercial substrate and can be used in order to reduce production costs without prejudice to the seedlings growth. The cultivation of Petunia x hybridain April resulted in seedlings with greater height, leaf length and greater accumulation of phytomass. The G. globosa seedlings showed greater development of the aboveground part and the root system, in addition to greater accumulation of phytomass when cultivated in October.