Yield and soil insect resistance in sweet potato clones
Sweet potato (Ipomoea batatas) is a rustic horticultural crop with high production potential. However, the crop is susceptible to many pests and diseases. The objective of this study was to evaluate 10 genotypes of sweet potato regarding their yield and resistance to soil insects, under Brazilian cerrado soil conditions. Genotypes were selected from the Sweet Potato Germplasm Bank of Embrapa Hortaliças. The experiment was conducted at Água Limpa Farm, belonging to University of Brasilia (UnB), and consisted of a randomized block design, with 10 treatments (genotypes), 10 plants per plot, and four replications. The following traits were analyzed: number of perforations per root, incidence of roots injured by insects, plant resistance degree, root shape, total and marketable root yields, root peel color, root pulp color, pulp total soluble solids, pulp titratable acidity, pulp TSS/TA ratio, pulp moisture, and pulp starch yield. Genotype CNPH 53 (26.78 t ha-1) presented total root yield greater than the commercial variety Brazlândia Rosada (17.54 t ha-1). Genotype Santa Sofia (11.77 t ha-1) and Brazlândia (13.5 t ha-1) had similar marketable root yields. CNPH 53 showed the best agronomic performance, exhibiting moderate susceptibility to soil insects and root shape meeting the market standards. It also had low pulp TA (2.53%); high pulp TSS (12.25 °Brix) and pulp TSS/AT ratio (4.24); pulp moisture content close to 70%; and the highest pulp starch content (11.98%). The traits number of perforations per root, root shape, and pulp TA presented heritability values close to 70%. Marketable root yield, pulp moisture, and pulp starch content demonstrated heritability values greater than 90% and CVG/CVE greater than 1.