Respostas de paricá e clones de eucalipto à inoculação de fungos micorrízicos e rizobactérias em área de neossolo quartzarênico em São Domingos do Araguaia – PA.

Abstract

This study had the objective to evaluate mortality and growth of different eucalyptus clones under inoculation of mycorrhizal fungi as well as and mortality and growth of paricá under inoculation of mycorrhizal fungi and rhizobacteria in the southeast of Pará state, Brazil. The experiment with the eucalyptus clones was installed following a randomized block design with three replicates (three blocks) with 12 treatments and six clones. The seedling spacing was 3.0 x 3.0 meters with each plot having 56 seedlings. Half of the seedlings were inoculated with the arbuscular mycorrhizals fungi (endomycorrhizal) Glomus etunicatum, Glomus clarum, and the ectomycorrhizal Pisolithus microcarpus and the other half of the seedlings had no inoculation and served as a control. Each eucalyptus clone had 168 seedlings, totaling 1008 seedlings. Up to the last experiment measurement, the inoculation with the mycorrhizal fungi did not promote higher growth in diameter and height of the eucalyptus clones tested, when compared to the treatment without inoculation. The clones VM01 Eucalyptus urocan, 373 E. platyphylla, and 1250 E. urograndis had the lowest mortality rates. Therefore, the most recommended clones for Southeastern Pará were VM01 E. urocan, A 2017 E. urograndis, 373 E. platyphylla and 1250 E. urograndis because they presented better growth in diameter, height and lower mortality rate. The experiment with paricá was installed following the randomized block design with three replicates (three blocks) for each treatment being one replicate with 49 individuals, totaling 147 trees per treatment. The seedling spacing was 3.0 x 3.0 meters. In total, 588 paricá seedlings were used in the experiment. The development of paricá was evaluated under the influence of four treatments: (T0) control, (T1) conventional chemical fertilization (thermophosphate and, in the cover, NPK), (T2) inoculation with arbuscular mycorrhizal fungi, and (T3) inoculation with arbuscular mycorrhizal fungi and use of the plant growth promoting rhizobacteria. Inoculation with the plant growth promoter rhizobacteria (Enterobacter sp., Enterobacter aerogenes, Bacillus sp. and Pantoea sp.) and arbuscular mycorrhizal fungi in the species Glomus ethunicatum and Glomus clarum during the period evaluated did not influence development in diameter, height, and mortality of paricá plants. The paricá trees with conventional chemical fertilization had the best growth in height and diameter and lower mortality rate. However chemical fertilization is recommended in paricá plantations up four years in age in southeast Pará.