Produção e qualidade de mudas de Hovenia dulcis thunberg (Rhamnaceae) em diferentes substratos

Abstract

In order to produce quality seedlings, it is important that the substrates used have physical and chemical characteristics favorable to the needs of the plants. In this scenario, some organic materials have been applied in mixtures of substrates to produce seedlings. This study aimed to analyze the feasibility of the use of sewage sludge as a substrate for the production of Houvenia dulcis Thunberg seedlings. The study was developed in a plastic greenhouse at the Universidade Federal do Pampa, São Gabriel, RS. The treatments were composed of different percentages of sewage sludge added to each organic compound: T1 (50 % commercial substrate Plantmax® + 50 % equine litter, taken as organic compost), T2 (20 % sewage sludge + 80 % organic compost), T3 (40 % sewage sludge + 60 % organic compost) and T4 (60 % sewage sludge + 40 % organic compost). The data were submitted to analysis of variance and the means discriminated by the Tukey test at 1 % of probability. Past 180 days after sowing, the percentage of emergence and other biometric characteristics were calculated, such as: shoot height, root system length, collection diameter, number of leaves, fresh and dry shoot mass, root system and total, and, finally, the Dickson quality index was calculated. The use of the commercial substrate associated with equine litter (organic compost) presented the lowest averages for most of the evaluated characteristics. It was verified that the treatments with sewage sludge associated to the organic compost, showed the best results for the morphological characteristics evaluated, being that the treatment 4 (60 % sewage sludge + 40 % organic compost) was the one that presented the best results for the production of seedlings of this species.