Decepa de plantas jovens de eucalipto em um sistema agroflorestal: dinâmica de copa e crescimento

• Autor(a) principal: Cacau, Filipe Valadão
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2975
• topic: Sistema agroflorestal; Clone; Eucalipto; Decepa de plantas jovens; Agroforestry system; Clone; Eucalyptus; Coppicing of juvenile plants; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA

The growth and the crown dynamics of intact plants and coppiced plants were evaluated in two clones of eucalypt stands in an agroforestry system (9.5 x 4.0 m) in Vazante, MG (17°36 09 S e 46°42 02 W). Intact plants were compared to sprouts growth from coppicing at the age of 9 and 12 months after planting, with no sprout thinning, and, sprout thinning applied 6 and 9 months after coppicing, to 2 and 3 sprouts per stump and, 12 months after coppicing, leaving all dominant sprouts. At the age of 42 months after planting, plant survival did not differ (p>0.05) among treatments and, the treatment without thinning showed about the same amount of sprouts per stump of those thinned to three sprouts per stump. The diameter and total height exhibited smaller (p≤0.05) estimated asymptotic value for sprouts as compared to intact plants. The sprouts of the clones 58 and 19 presented, respectively, 69 and 77% of the value of the estimated diameter for the intact plants. The estimate of the asymptotic value for the volume per hectare of the sprouts of the clone 58 was similar (p>0.05) to the one from intact plants in most treatments when coppiced at 9 months after planting. Clone 19 coppiced at 12 months after planting presented estimated volumetric production similar to that of the intact plants. At 24 months after planting, the leaf area index (LAI) of the coppiced stands was smaller (p≤0.05) than that of intact plants. At this age, the clone 19 showed the least LAI (0.32) in the inter-rows, as compared to the clone 58 (LAI= 0.52). At 42 months after planting crown projection and LAI did not differ (p>0.05) between treatments, for the two clones. The overall results suggest that coppicing of juvenile eucalypt plants should be performed as soon as possible, without thinning, when one intends to produce small diameter logs without reduction of the productivity of the agroforestry system.