Productive characteristics of sweet potato clones in three cultivation periods in São Cristóvão, Sergipe State, Brazil

O objetivo do presente trabalho foi avaliar o desempenho de clones de batata-doce cultivados em diferentes períodos. O delineamento experimental foi de blocos casualizados, em esquema de parcelas subdivididas, com três repetições. Foram testados nas parcelas três períodos de cultivo (3, 5 e 7 meses), e nas subparcelas, cinco clones de batata-doce (acessos IBP-007, IBP-038, IBP-075, IBP-079 e IBP-149), e a cultivar comercial Brazlândia Rosada. As variáveis analisadas foram sobrevivência, danos causados por insetos de solos (notas de 1 a 5 onde 1= sem danos e 5= muitos danos, sem valor comercial), massa fresca e seca de parte aérea, produtividade total de raízes. Os maiores danos causados por insetos de solo observou-se no clone IBP-007 (4,29), e menores danos nos clones IPB-038 (2,84), IPB-075 (3,01) e IPB-149 (2,88), que apresentaram resistência no cultivo durante sete meses. O clone IPB-007 apresentou elevados valores de massa fresca (14,07 t/ha) e seca (2,81 t/ha) de parte aérea, em todos periodos de cultivo, apresentando também, alta produtividade de raizes (33,16 t/ha). Recomenda-se cultivar a batata doce durante um período de cinco meses._________________________________________________________________________________________ ABSTRACT: 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