RYEGRASS Lolium perenne L. YIELD AT DIFFERENT HARVEST FREQUENCIES AND FERTILIZATION SCHEMES WITH SARGASSUM SEAWEED (Sargassum spp.)

Abstract

The use of seaweed or Sargassum as a biostimulant is an alternative to chemical fertilizers in agricultural systems. The objective of this study was to evaluate the yield of perennial ryegrass (Lolium perenne L.) subjected to different harvest frequencies and fertilized at different biofertilizer concentrations based on brown seaweed or Sargassum (Sargassum spp.) over a one-year period. For this, concentrations of 0, 2, 5 and 8% of the biostimulant and defoliation intervals of 28, 35 and 42 days were considered as factors, evaluating the four seasons of the year. The variables evaluated were dry matter yield, Soil Plant Analysis Development in Soil (SPAD) units, plant height, and leaf tissue production. A completely randomized design was used, with a 4x3 factorial arrangement with 4 replications per treatment. Mean comparisons were performed by Tukey test (P<0,05), using a factorial ANOVA in SAS software (2002). The results showed that, except for SPAD units, the Sargassum extract had no effect (P<0,05) on any of the variables evaluated. Regarding harvest frequency, the 42-day interval showed the highest forage yields, plant height, and leaf production over the seasons evaluated, but there was no effect on the accumulated dry matter yield. It is concluded that the highest level of Sargassum extract (8%) influences chlorophyll concentration, while harvest frequency and season of the year have effects (P<0,01) on yield variables.