Substituição do substrato comercial por casca de arroz carbonizada para produção de mudas de cafeeiro em tubetes na presença de polímero hidrorretentor

Abstract

With the purposes of verifying the effect of the replacement of the commercial substrate by carbonized rice husk and the addition of hydroretentive polymer on the development of coffee tree seedlings in 120 mL tubes, an experiment was conducted at the Coffee Culture Sector of the Universidade Federal de Lavras - UFLA, from April 2002 to November 2002. The experiment was set up according to a four-replicate randomized complete-block design, with a 5 x 2 factorial arrangement. Plots was comprised of 13 tubes, the five central ones considered as the useful experimental area. Treatments studied consisted of the five proportion of the replacement of the commercial substrate to carbonized rice husk (0%, 25%, 50%, 75% and 100% of replacement) in the presence and absence of hydroretentive polymer. The cultivar employed was Acaiá Cerrado MG-1474. The results obtained enable to conclude that the replacing of commercial substrate for toasted rice coat between 60 and 70%, confer greater increase in the seedlings in least time and the incorporation of hydroretentive polymer in dose of 10 kg m-3 in the substrate, damaging the growth of ones.