Weeds interference in the implantation and regrowth of Panicum maximum cv. Massai pasture

Abstract

Inadequate weed management is one of the key causes of low productivity of Brazilian pastures. The objective of this work was to evaluate the effects of weed interference on the implantation of Panicum maximum cv. Massai and the regrowth after cutting. Two trials were conducted in randomized blocks with four replicates. In the first experiment, the forage was maintained with weeds for the periods 0, 7, 14, 21, 28, 35, 42, 49, 56 and 66 days after emergence (DAE) of the pasture. The second experiment, the P. maximum cv Massai was maintained without the weed coexistence for the same periods until the forage cut, at 66 DAE. The plots were kept free from the weed coexistence by manual weeding, according to the treatment. With the increase of the periods of coexistence of the weeds with the forage, greater damages were observed in the production of tillers and in the forage yield in the pasture implantation. The critical period of weed interference in the P. maximum cv. Massai stood between 11 and 49 DAE. Weed interference also affected forage regrowth at 40 days after cutting, reducing tillering, plant cover and dry mass production, mainly leaves.

Keywords

• períodos de interferência. comunidade infestante. rendimento de forragem. competição.