PRODUCTION OF Pinus durangensis Mart. UNDER DIFFERENT SUBSTRATE AND MYCORRHIZAL INOCULATION CONDITIONS IN NURSERY

Abstract

Substrate and mycorrhization are important aspects when producing plants. The objective of the study was to determine the effect of three substrates inoculated with ectomycorrhizal fungal spores on the morphological characteristics of nursery-grown Pinus durangensis as well as the inherent costs of the substrate. A randomized block experimental design with a 3 x 3 factorial arrangement was used. The substrates evaluated were: 1) peat, vermiculite, and perlite (50:25:25) [PVP]; 2) peat, composted bark, and raw sawdust (50:25:25) [PBS]; and 3) peat and bark (50:50) [PB]. The mycorrhizal inoculants were: 1) Pisolithus tinctorius; 2) Laccaria laccata; and 3) control. The plant was produced in black polyethylene tubes (160 mL) and evaluated at 13 months. The substrate factor presented statistical differences (p ≤ 0.05) in the variables evaluated, with higher values in PVP, followed by PBS and PB, the latter being similar to each other. The mycorrhizal inoculation factor showed differences (p ≤ 0.05) in root and total biomass, Dickson’s quality index, and mycorrhizal colonization, obtaining higher values when P. tinctorius was inoculated, except in the last variable, where the application of L. laccata stood out. In the substrate-mycorrhizal inoculation interaction, the most favorable combination was PVP and P. tinctorius. The PVP substrate was 28.4 and 34.6 % more expensive than PB and PBS, respectively. The combined effect of PVP and P. tinctorius produced the best growth, although the substrate was more expensive.