Time of contact of phosphate fertilizer with Megathyrsus maximus (cv. Massai) seeds in relation to germination and growth

Abstract

The aim of this research was to evaluate the effect of the contact time of simple superphosphate fertilizer with Massai grass (Megathyrsus maximus) seeds on the physiological quality of the seeds. The experiment was conducted with seeds of Massai grass in two conditions: laboratory and field. The experiment was carried out in Teresina, Piauí, Brazil. The experimental design was completely randomized, with three replicates for both conditions. The treatments consisted of seven contact times: 0, 3, 6, 9, 24, 48, and 72 h. Germination (GP) and emergence (EP) percentages, seedling height (SH), root length (RL), and germination speed index (GSI) were evaluated. The contact time of the fertilizer with the seeds had a significant effect on all variables, except root length and emergence at 7 d. For GP in the second data collection and GSI, there were no differences up to 3 h of contact; however, for GP in the first collection, SH and GSI at 21 d, the contact of seeds with fertilizer for 3 h already had negative effects on these variables, reducing them by 23.33%, 12.13 cm and 14.28% respectively. The longer the contact time between single superphosphate with M. maximus (cv. Massai) seeds, the lower the germination and vigor values.