Características produtivas de clones de batata-doce cultivados em três períodos de cultivo em São Cristóvão-SE

The aim of this work was to evaluate the performance of sweet potato clones grown in different cultivation periods. The experimental design was a randomized block design, in a split-plot scheme, with three replications. Tests in the plots were three cultivation periods (3, 5 and 7 months), and in the split plots, five sweet potato clones (accessions IBP-007, IBP-038, IBP-075, IBP-079 and IBP-149), and the commercial cultivar Brazlândia Rosada. The studied variables were: survival, damages caused by soil insects (grades from 1 to 5 being 1= without damage and 5= very damaged, without commercial value), fresh and dry weight of the shoots, total root yield. The greatest damages caused by soil insects were observed on the clone IBP-007 (4.29) and the smallest damages were observed on the clones IPB-038 (2.84), IPB-075 (3.01) and IPB-149 (2.88) which presented resistance during the seven month cultivation period. Clone IPB-007 presented high values of fresh (14.07 t/ha) and dry weight (2.81 t/ha) of aboveground part in all the cultivation periods. Clone IPB-007 also presented high root yield (33.16 t/ha). We recommend the use of the cultivation period of five months.