Mini-tunnel and season influence in clonal garden on the production of clonal seedlings for two subtropical clones: Eucalyptus saligna and Corymbia torelliana × Corymbia citriodora

Abstract

Improving technologies for clonal seedling production is essential due to the expansion of forestry production areas. The objective of this study was to assess the impact of managing mini-tunnels in a clonal mini-garden on the productivity and physiological quality of mini-stumps, as well as on the survival and rooting of mini-cuttings of Eucalyptus and Corymbia clones throughout the four seasons. For this purpose, the experiments were conducted in two phases: in the first phase, the clonal mini-garden phase, two clonal mini-gardens were established, one with a mini-tunnel and the other without. Each mini-garden contained mini-stumps of Eucalyptus saligna and hybrid clones of Corymbia torelliana × Corymbia citriodora. During this phase, environmental variables (temperature and relative humidity) were monitored in the cultivation environments (a mini-garden with and without a mini-tunnel), along with productivity and hydrogen peroxide concentration. In the second phase, in the rooting house, survival (%) and rooting (%) were evaluated. The use of minitunnels increased environmental variables near the mini-stumps throughout all four seasons. The presence of the mini-tunnel promoted an increase in mini-stump productivity for both genetic materials throughout the year and positively influenced the survival and rooting of mini-cuttings, demonstrating the effectiveness of the structure in ministump preconditioning, especially during seasons with lower temperatures. Therefore, the use of mini-tunnels in the clonal mini-garden during autumn and winter is recommended to increase the production of Eucalyptus saligna and Corymbia torelliana × Corymbia citriodora seedlings.