Effect of plant density and genotype on root size and recovery of Cenourete® raw-material

Abstract

Cenourete® is a cut and peeled mini carrot, produced by the abrasion of 55-60 mm cylindrical carrot root segments. The longer and the thinner the carrot root, the higher is the recovery of Cenourete®. Two new carrot genotypes obtained at Embrapa Hortaliças, Brasília, Brazil, populations 1012568 (P68) and 1012575 (P75), and the cultivar Esplanada were evaluated in relation to the production of roots for mini carrot manufacture. Two crops were cultivated in the summer of 2010-2011 under the densities 8, 10 and 12 lines/meter in order to obtain respectively 1.06, 1.33 and 1.60 million plants/ha and harvested approximately 3 months after sowing. We evaluated the total root production (kg/ha), the diameter, the length and the weight of individual roots and the production of root pieces 60 mm long with diameter in the ranges <15 mm, 15-25 mm, 25-30 mm. Total yield of 60 mm root pieces varied from 19,000 to 34,000 kg/ha depending on treatment. Total yield from cv. Esplanada was significantly higher than yield from genotypes P68 and P75 which did not differ from each other. The new genotypes produced longer and thinner roots compared to cv. Esplanada, what resulted in higher production of smaller root pieces (diameter <15 mm) and a corresponding lower proportion of larger pieces (diameter of 25-30 mm). Plant density had no influence on the total production of root pieces but affected the recovery of particular size ranges, with the proportion of smaller pieces increasing at higher density. The amount of cut waste varied from about 3,000 to 7,000 kg/ha depending on treatment. Cv. Esplanada produced a higher mass of cut waste than P68 and P75 due to a larger amount of pieces with diameter higher than 30 mm. Although increased plant density reduced root size of all genotypes, the variation in root length and root diameter was mainly due to genotype effect.