Dynamics of weeds after application of oxadiazon with simulated water depths and incorporation of organic material

Abstract

The objective of this work was to determine the effect of oxadiazon in the behavior of the weed community under different moments of application of water depths and incorporation of organic material. A randomized block design was used with treatments arranged in a factorial 5 x 2 with four replications. The treatments consisted of combination of with or without incorporation (8 t ha-1) of organic material in the soil and the moments of application of water depths (0, before 10 mm, after 10 mm, and sequential 10 mm before and after application of oxadiazon), and the control (0 mm water and 0 g ha-1 of oxadiazon). Relative density, relative frequency, relative abundance, importance value index (IVI) and similarity index (SI) of the weed flora were obtained. No significant interaction between the organic material and water depths was observed. Cyperus rotundus showed higher IVI, regardless of the experimental treatment, followed by Urochloa decumbens, Galinsoga parviflora, Bidens pilosa and Melampodium perfoliatum. The highest similarity (SI = 0.75) was observed between treatments with the application of 10 mm water depth before associated with the 10 mm after the application of oxadiazon.