Productive characteristics of sweet potato clones in three cultivation periods in Sao Cristovao, Sergipe State, Brazil

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 Brazlndia 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 IPB038 (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.