Uso de substratos orgânicos no crescimento inicial de mudas de pau-de-balsa Ochroma Pyramidale (Cav. ex Lam.) urbam

Abstract

The success of reforestation projects, recovery of degraded areas and other types of forest plantations depends, among other factors, on the correct choice of species and the characteristics of the seedlings taken to the field. Therefore, information on the forestry of these species, their light, water and nutritional requirements, as well as their behavior and growth from germination to the seedling phase and their establishment in the field are required. The species Ochroma pyramidale (Cav. Ex Lam.) Urbam. popularly known as balsas wood, belongs to the family Malvaceae, reaches up to 30 m in height, has a trunk between 60 and 90 cm in diameter and can be found in the humid forests of South and Central America, extending from the south from Guatemala to northern Brazil and Bolivia. The objective of this work was to investigate the growth responses of Ochroma pyramidale seedlings submitted to different organic fertilization treatments. The following substrates were tested: black soil (T0); black soil + tanned bovine manure, in the proportion 3: 1 (T1); black soil + tanned sawdust, in the proportion 3: 1 (T2); and, black soil + manure + sawdust in the proportion 3: 1: 1 (T3). The biometric variables analyzed were leaf number (NF), neck diameter (DC), leaf area (AF), shoot dry mass (MSPR), total height (H), root dry mass total dry matter (MST). The data were submitted to analysis of variance and the means were compared by the Tukey test, at 5% probability. The addition of manure provided a three - fold increase in height and leaf area in comparison to the control treatment. The addition of sawdust inhibited the growth of the seedlings and presented the lowest values in all analyzed variables. It is recommended to use black soil + 3: 1 tanned cattle manure for the production of rattlesnake seedlings and the use of sawdust is discouraged even in combination with cattle manure.