Forests, Vol. 16, Pages 901: Developmental and Physiological Effects of the Light Source and Cultivation Environment on Mini Cuttings of Eucalyptus dunnii Maiden

Forests doi: 10.3390/f16060901

Authors:
Thalia Schilisting
Alexandra Cristina Schatz Sá
Daniel Pereira da Silva Filho
Valéria Martel da Silva
Marcio Carlos Navroski
Mariane de Oliveira Pereira
Bruno Nascimento
Carolina Moraes
Ramon Silveira de Andrade
Regiane Abjaud Estopa
Leticia Miranda

Eucalyptus cultivation in Brazil benefits from techniques such as mini cutting; however, adverse climatic conditions in the southern region of the country limit seedling production. This study evaluated the effects of LED lighting (blue, red, combined, and natural) and cultivation environments (greenhouse with and without heating, and conventional nursery) on the propagation of Eucalyptus dunnii. The experiment, conducted in Otacílio Costa, SC, followed a two-factor (4 × 4) design with biweekly data collection from March to September 2024. Variables analyzed included sprout productivity, rooting performance, phytosanitary status (powdery mildew incidence), physiological parameters (photosynthetic rate, stomatal conductance, transpiration), and nutritional content. The results showed that LED lighting and cultivation environments did not affect the incidence of powdery mildew. Rooting was enhanced during winter in the heated mini-tunnel system. Sprout productivity was highest in the mini tunnel (~360 sprouts/m2 under red light in winter), while heated environments led to a reduction in sprout production. Physiological variables such as photosynthetic rate and stomatal conductance were improved in the heated mini-tunnel, and transpiration responded to the interaction between light spectrum and environment. The evaluated factors did not cause significant changes in the nutritional profile of the mini stumps. It is concluded that the mini tunnel, particularly when heated during winter, enhances rooting and physiological responses, while red LED light increases sprout productivity. Supplemental LED lighting proved to be a strategic tool for overcoming seasonal limitations in Eucalyptus propagation.

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