Influence of the Replanting Age on Yield and Growth of Eucalypt Clonal Stands

Abstract

The growth of an eucalypt plantation should be monitored to identify factors that influence its development, helping in the decision-making process, aiming to reduce productivity losses. Thus, the objective of the present study was to evaluate the influence of the age of replanting on the yield and growth of eucalypt stands. The experiment was conducted in an area of CENIBRA S.A. Company, and established in a commercial plantation in August 2011. The application of herbicide and the ant control were performed in total area before planting. Seedlings of Eucalyptus urophylla × Eucalyptus grandis clones in 3.0 × 2.5 m spacing were used. Limestone (1,500 kg ha-1) was applied in total area before planting and 100 g plant-1 of NPK fertilizer (06-30-06) was applied immediately after planting. Four months after the installation of the experiment, 300 kg ha-1 of NPK (06-10-29) was applied. Treatments consisted of four dates of seedling replanting (0, 20, 40 and 80 days after planting) without complementary fertilization, and two treatments (replanting 40 and 80 days after planting) with supplementary fertilization (100g plant-1 NPK 06-30-06). The individual volume of replanting trees was 46.6% lower than of non-replanted ones. Treatments with complementary planting fertilization did not differ (p > 0.05) by the T-test. It is concluded that the longer the time between planting and replanting, the smaller the individual volume of the replanting trees and that the complementary fertilization in seedlings replanted does not favor their growth.

Investments in Pinus elliottii Engelm. Plantations: Real Options Analysis in Discrete Time

“…We evaluated the following silvicultural operations pre-planting: mechanized weed mowing, manual control of leaf-cutting ants with ant traps (Mirex-S ® active ingredient sulfluramid), and soil preparation with a subsoiler pulled by a tractor [47][48][49]. After the planting of Pinus elliottii seedlings produced in polyethylene tubes, we evaluated the following silvicultural operations: replanting, manual and mechanized weed mowing until 1 year after planting, manual control of leaf-cutting ants with ant traps until 3 years after planting, mechanized application of post-emergence herbicide (Roundup Original ® active ingredient glyphosate) until 4 years after planting, pruning, and thinning [47,48,[50][51][52]. The maintenance of firebreaks started in the 1st year and ended in the 21st year.…”