Métodos de controle de plantas daninhas em restauração florestal

Abstract

Weeds in forest restoration projects can represent barriers to the development of seedlings of native species due to their high aggressive and competitive potential, in addition to corresponding to a considerable portion of investments in forest restoration projects for the control and maintenance of areas. Thus, studies focused on weed control methods are essential to improve the ecological and financial sustainability of projects to recover degraded areas. This work sought to evaluate the effectiveness of different weed control methods and their costs for the maintenance of forest restoration areas. The study evaluated six control methods: control using glyphosate herbicide, manual crowning and three physical controls, using straw, cardboard and fiber bag, in addition to the control treatment without intervention. The experimental design was in completely randomized blocks, being implanted in an area of 0.1 hectare at the Federal University of Lavras using a total of 210 seedlings of native species in the region. The survival rates at 3 and 10 months after planting, the morphological characteristics of total height and collar diameter, at 5 and 10 months after planting were analyzed for the species Anadenanthera colubrina, Anadenanthera macrocarpa and Guazuma ulmifolia, as well as the values of investment for the maintenance of the area and the control efficiency of each treatment, measured by the amount of weed biomass in each treatment. At 3 months after planting, the treatment with straw presented the highest percentage of live seedlings, and at 10 months after planting, the treatment with manual crowning showed the highest percentage of survival. All control methods showed high efficiency, favoring the growth of seedlings to the detriment of weeds, with no statistical difference between them for gains in height and diameter at 5 and 10 months after planting for species Anadenanthera colubrina, Anadenanthera macrocarpa and Guazuma ulmifolia. The control with cardboard was highlighted, which presented the best results for weed control. Regarding maintenance costs, straw presented the lowest cost for implantation and maintenance of the area.