Adaptive potential and productivity of two Salix viminalis L. clonal varieties grown in North Central Bulgaria

Salix viminalis L. is a broadly cultivated willow species that has been intensively used for breeding purposes, particularly in selection of clones and hybrids biomass production. The present study aimed to explore compare growth adaptability two basket (Salix L.) clonal varieties - rubra purpurea at the specific edaphic climate conditions cultivation practice presented an experimental plantation North Central Bulgaria. influence spacing, genotype, root age rotation on their productivity were also investigated allometric relationships non-destructive estimation woody plant suggested. trial was established spring 2018 as 4 sectors Nelder wheel plot with 15 nearly-square spacings, ranging from 0.25 9.80 m2 (40000–1020 plants per hectare). arranged four-spoke (2 clone). Data collection took place 2020 comprised 1- 2-year rotations. showed var. more susceptible desiccation-causing adverse climatic changes, poorly adapted site gradually died out during second third year. exhibited steady survival rate (97 77%) annual varying 3 17 Mg/ha/year across densities, years. During first year variety had significantly higher weight sprout number than variety. Growing space affected positively shoots tree dendromass, sprouting reinforced by coppicing doubled shoot subsequent rotation. This reflected development stump-level models differentiated according model predictive power based main length number. An exponential relationship breast-height diameter suggested each separately.