Emergence of Brachiaria plantaginea (Link) Hitch. in two regions of Paraná State, Brazil

Abstract

The objective of this experiment was to determine the periodicity and intensity of emergence as well as the survival of Brachiaria plantaginea (Link) Hitch. seeds in two regions of Paraná State, Brazil. A randomized complete block in factorial design 2 x 3 x 2, with three replications was used. The factors studied were: seed survival in the soil; seed burial depth, and soil management. Ceramic cylinders were installed in a wheat/soybean rotation under field conditions. The cylinders were filled with sterilized soil up to the limits established for the depth of seed distribution. A plastic net was placed into the cylinders to separate the treated soil from the untreated soil used to fill the cylinders. Three hundred seeds of B. plantaginea were mixed to the untreated soil. The weed seedlings were counted every 14 days and pulled out of the cylinders. The highest peak of B. plantaginea emergence occurred in the summer, coincidently with the period of highest temperature and rainfall. There was more emergence in tilled than in no-tilled soil. The highest emergences occurred in the smallest depth. The germination percentage of the seeds removed from the cylinders was higher in one year than two-year buried seeds.