Tipos de fertilizações e diferentes substratos na produção de mudas de cafeeiro (Coffea arabica L.) em tubetes

Abstract

With the aim of evaluating the effects of two types of fertilization and different substrates on coffee tree cutting production in containers, two experiments were set up in the Coffee Culture Sector of the Federal University of Lavras-UFLA under greenhouse conditions. The experiments were set up according to a four-replication randomized complete block design. Plots comprised of 17 containers, the five central ones considered as the useful experimental area. In both experiments substrates had the following composition: 60% organic compound, 20% vermiculite and 20% subsoil earth (S1); 60% bovine manure, 20% carbonized rice husk and 20% subsoil earth (S2); 60% bovine manure, 20% vermiculite and 20% subsoil earth (S3); 60% organic compound, 20% carbonized rice husk and 20% subsoil earth (S4); 60% bovine manure, 20% vermiculite and 20% carbonized rice husk (S5); 80% bovine manure and 20% subsoil earth (S6) and 100% commercial substrate constituted of vermiculite and ground pinus bark compounded and enriched (S7). In one of the experiments fertilization of substrates was done by utilizing the osmocote fertilizer (15-10-10 + micronutrients) at the dose of 300 g / 55 liters of substrate, applied uniformly mixed on it. In the other, the basic fertilization was done by means of the following mixture of fertilizers: 1.0 kg of simple superphosphate, 0.2 kg of ammonium sulfate, 0.05 kg of potassium chloride and 0.05 kg of FTE BR-9, applied on to 100 liters of substrate and further supplemented with sidedressing fertilization (25 g of ammonium sulfate plus 60 g of potassium chloride dissolved in 10 liters of water) applied to 3 m2 of the experimental unit. Stiff plastic 120-mL containers were used . For development evaluation of tree cuttings, number of pairs of true leaves, stem diameter, plant height, leaf area and root and shoot dry matters were determined. The results showed that carbonized rice husk in place of vermiculite showed same effect upon cutting production under both types of fertilization; substrate S6 allowed cutting production with the same standard, regardless fertilization type; substrates S1 and S4 enabled to obtain coffee tree cuttings with development compared with those produced in the plantmax substrate fertilized with osmocote. Plantmax substrate fertilized with the mixture of fertilizers showed low efficiency in forming coffee tree cuttings.