Efecto de diferentes áreas de control de malezas sobre el crecimiento de teca (Tectona grandis L.f.), en Pocosol, San Carlos, Costa Rica

Introduction. Weed control is an essential management activity in forest plantations to ensure tree survival and growth. Objective. Evaluate the effect of different weed chemical control areas on the growth of Tectona grandis. Materials and methods. Two experiments were established in Pocosol, San Carlos, Costa Rica. Each experiment was established under a randomized complete block design with four replications and four treatments: total application, 1.20-m-diameter circles around individual trees, 1.20-m-wide strips and 2.40-m-wide strips. Total height and diameter were measured at 3, 6, 12 and 24 months. In addition, the amounts of herbicides used and application times were recorded to estimate the average application costs per hectare. Results and discussion. The total application and 2.40-m-wide strips showed the highest growth values. At 24 months, no significant differences were observed between these two treatments in Experiment 2. The amount of spray mixture applied (water + products) increased with the control area, with volumes ranging from 102 to 339.63 L ha⁻¹. The estimated time required to complete one forest hectare ranged from 5.07 to 15.18 hours ha⁻¹, with total application requiring the longest time. Total costs per forest hectare ranged from $ 26.73 to $ 84.25, with the 1.20-m-diameter circles around individual trees and 1.20-m-wide strip treatments being the least expensive. Conclusion. An increase in the weed control area was associated with higher diameter and height growth in teak trees. The 2.40-m-wide strips constitute a weed control alternative, as they resulted in growth values close to those obtained with total application.