Produção e qualidade de mudas de Psidium Cattleianum Sabine Var cattleianum (Myrtaceae) em diferentes substratos

Abstract

Substrates play an important role in the production of quality seedlings, because they need to present physical and chemical characteristics appropriate to the needs of plants. In this context, some organic materials have been used in the composition of substrates for seedling production. This study aimed to analyze the use of sewage sludge in substrates for Psidium cattleianum Sabine var. cattleianum seedlings production. The study was carried out in plastic greenhouse at Universidade Federal do Pampa, São Gabriel, RS, Brazil. The treatments were composed by different sewage sludge percentages in addiction to a compost organic: T1 (50 % commercial substrate + 50 % horse bedding - compost organic), T2 (20 % sewage sludge + 80 % organic compost), T3 (40 % sewage sludge + 60 % organic compost) e T4 (60 % sewage sludge + 40 % organic compost). The treatments were arranged in a completely randomized design, with five replicates per treatment, each with 50 seeds each. The data were submitted to analysis of variance and the means discriminated by the Tukey test at 5% of probability. Every three days during 90 days, seedling emergency were evaluated for the determination of the emergency speed index. 180 days after sowing, the percentage of emergence and other biometric characteristics were calculated, such as: aerial and root length, stem diameter, number of leaves, fresh and dry mass of aerial part, root system and total, and Dickson's quality index. The composition of commercial substrate + horse bedding (organic compost) presented the lower averages for all characteristics evaluated. It was found that treatments with sewage sludge associated with organic compound presented the best results for the morphological characteristics evaluated, and the treatment 3 presented better results for the seedlings production of this species.