Survival and growth of Pinus engelmannii Carr. in a reforestation from mycorrhization and fertilization

Abstract

In a forest nursery, seedlings are provided the necessary care and inputs to promote its quality, in order to have a greater chance of survival and growth during their initial stages. The objective of this study was to assess survival and growth in diameter and height of P. engelmannii in a reforestation task, based on the incorporation of commercial mycorrhizal inoculants in the preconditioning stage in the nursery and slow release fertilizer at the planting time. Six treatments were evaluated: endomycorrhizal inoculant with spores of Glomus; ectomycorrhizal inoculant with spores of Amanita rubescens, Amanita sp., Lactarius indigo, Ramaria sp. and Boletus sp.; ectomycorrhizal inoculant with spores of Pisolithus tinctorius and Scleroderma citrinum; combined with and without slow release Multicote 8^® granular fertilizer (8-9 months) (11 N-28 P₂O₅-11 K₂O + micronutrients). The response variables recorded were: survival and cause of mortality, stem diameter and height. Survival was found to decrease gradually and at 12 months it ranged from 57 % to 83 % between treatments, with statistical differences; there were significant differences in the diameter and height variables from three to 12 months. The treatments with ectomycorrhizal inoculant without fertilization had greater survival, while the treatments with inoculant and fertilizer showed greater increase in diameter and height. It is concluded that controlled inoculation had an impact on survival, while fertilization had an effect on the growth of P. engelmannii in the field.