EFFECT OF SUBSTRATE AND MYCORRHIZAL FUNGI ON ROOT DEVELOPMENT OF ORANGE CUTTINGS (Citrus sinensis Osb. cv. Valencia)

Abstract

 In the State of Rio Grande do Sul (Southem Brazil) the time spent to produce citrus grafted seedlings is approximately three years. It is suggested that Chis time may be reduced up to 18 to 24 months. Also, studies indicate that mycorrhizal fungi improve nutrient uptake by citrus plants. Based on these findings, an experiment was carried out in a greenhouse at the Agronomic Experimental Station using intermitent mi st and comparing different substrates associated with 30% of soil, for rooting 'Valencia' orange outtings. The following substrates were tested: carbonized rice hull, manure and decomposed bark of The inoculation of the substrates with Glomus etunicatus and G. clarum was also evaluated. The experimental Acacia molissima. design was a 3 x 3 factorial in a randomized block with four replications and 10 cuttings per plot. The results indicate that manure increased rooting and old leaves retention. However, the substrate had no effect on the development of new leaves. The mycorrhizal fungi did not affect rooting and the development of new leaves, although G. etunicatus favored old leaves retention.