Phytosociology of Weeds in a Coffee Plantation Intercropped with Legume Crops

作者：Moreira G M^*; Oliveira R M; Barrella T P; Fontanetti A; Santos R H S; Ferreira F A

来源：Planta Daninha, 2013, 31(2): 329-340.

• Green manure
• Coffea arabica
• community similarity
• importance value index

The objective of this study was to evaluate the phytosociology of weeds in a coffee plantation under different periods of legume intercropping, along two years. The experiment consisted of nine treatments in a randomized block design with four replications. Treatments were the factorial combination of Jack beans (Canavalia ensiformis) or Hyacinth beans (Dolichos lab-lab) and four periods of intercropping with coffee (30, 60, 90, and 120 days after planting), plus a control treatment with no legume. The legumes were sown in December 2007 and October 2008, cut according to the periods of intercropping, and placed under the coffee plant canopies. Weeds were sampled on the coffee plant inter-rows and canopies, in October 2008, and October 2009, reflecting the effect of treatments after one and two years of cultivation, respectively. The evaluations consisted of the weed community indices, the species' importance value and the relative importance of the most frequent weed species. In both years, seventeen species of weeds, distributed in ten botanical families, were identified, with the most frequent species being Cyperus rotundus, Paspalum conjugatum, Amaranthus retroflexus and Oxalis latifolia. In the first-year, Jack beans (2.65 t ha(-1)) accumulated more mass than Hyacinth beans (1.89 t ha(-1)), but in the second year, the Hyacinth beans accumulated more mass (4.21 t ha(-1)) than the Jack beans (2.73 t ha(-1)). At the end of the two years, the weed flora in the control plot was more similar to the flora under the canopy than on the inter-row flora. In 2008, when Hyacinth beans were intercropped for 90 or 120 days, the relative importance of C. rotundus in the inter-row was higher than in the control. On the other hand, in the second year, the relative importance of this weed was higher in the control plots, and in 2009, the relative importance of this weed was higher in the control. The weed mass in the inter-row was higher than under the coffee plant canopy, possibly due to the shading provided by the trees. C. rotundus was the most important species in both years, followed by Paspalum conjugatum, whose importance increased from 2008 to 2009, possibly due to its adaptation to low light conditions.

• 出版日期2013-6