AVALIAÇÃO DO RENDIMENTO DA PRODUTIVIDADE E QUALIDADE DE RAÍZES DE BATATA-DOCE (Ipomoea batatas (L.) Lam) PLANTADAS EM RONDÔNIA

Abstract

The objective of this study was to evaluate the yield and quality performance of sweet potato cultivars grown under tropical climate conditions in the city of Ji-Paraná, state of Rondônia at 156m above sea level, latitude 10° 57’ 28’’ S and longitude 61° 54’ 21.57’’ W. Regarding yield, it was verified whether the use of appropriate planting techniques will increase the productivity of potatoes with nutritional quality. The treatments were composed by the cultivars BRS Rubissol (T1), Beauregard (T2), BRS Amélia (T3), Brazlândia Branca (T4), Brazlândia Roxa (T5), BRS Cuia (T6) and the control of a local variety, Roxinha (T7). The experiment was set in a complete randomized block design (CRB), with five blocks and seven plots of each cultivar in each of them. Planting started on November 28, 2017 in which NPK fertilization was used for planting and the topdressing fertilization used only nitrogen, 40 days after planting. Mechanical weeding was carried out whenever it was necessary. No incidence of diseases was observed, and control of pests was performed initially with manual collection and, as incidence increased, defensive Decis® was applied. Harvest was carried out on May 28, 2018 and its evaluated traits were, as follows: root average weight, total yield, average root diameter, average length, commercial standard classification, soil insect damage, root shape, non-marketable root productivity, marketable roots productivity, average number of roots, dry matter, ash, starch, fiber, soluble solids and pH. The cultivars that presented the greatest yield of weight, total productivity, commercial root productivity and sweet potato root diameter in Rondônia were Beauregard, BRS Amélia and Brazlândia Branca, which were considered good alternatives for sweet potato producers. The best quality of production was attributed to the cultivar BRS Rubissol for presenting dry matter greater than 30%, starch content within the ratio of 20 to 30%, ideal glucose range for use in industrialization. In relation to the resistance to pests, diseases and formats, with the exception of the BRS Cuia cultivar without commercial root production, all the others presented root with little damage, but observable, with acceptable commercial aspect however, predominantly fusiform, but with some unevenness with possible presence of veins or curvatures in the root. Variety BRS Cuia, from a temperate climate, presented a vegetative development, but did not show root production with a commercial pattern. Therefore, it is recommended the reproduction of new experiments with the same cultivar, to guarantee this information before discarding its use in the state of Rondônia.