CRESCIMENTO E DESENVOLVIMENTO DE TRÊS CULTIVARES DE CANA-DE-AÇÚCAR, EM CANA-PLANTA, NO ESTADO DO PARANÁ

The objective of this work was to analyze the growth pattern of three different cultivars of sugarcane, RB72454, RB855113 and RB855536, at plant cane stage through growth analyses, determination of growth stages, photosynthetic production dynamics, leaf area index, dry matter accumulation and growth rate. The experiment took place at the Parana State Federal Universty Experimental Station located in Paranavai (Parana State) between March 4th, 2002 and July 14th, 2003. The statistical design used was random blocks, with five replication per tested variety. The treatments were composed by three varieties, RB72454, RB855113 and RB855536, in plots with 12 rows of 6 meters, with 1.40m between rows. Nine evaluations were perfomed during a 497 day cycle. Different rates of growth were observed among the cultivars, with RB72454 presenting the higher crop growth rate (CGR) (15.4 g.m -2 .day -1 ). Three major growth stages were observed: intense tillering until 231 DAP; a second stage; height growth, increased of photosynthetic leaf area index (LAI) and intense accumulation of dry matter between 231 and 377 DAP; and a third stage, maturation, between 377 and 497 DAP, showing higher rates of CGR.