Konahomare ; a new sweetpotato cultivar for starch production

Konahomare is a newly released cultivar with a high starch content and high yield, developed at the National Agricultural Research Center for Kyushu Okinawa Region, (formerly Kyushu National Agricultural Experimental Station). It was evaluated at prefectural agricultural experimental stations as breeding line ""Kyushu No. 126"" and was officially registered by the Ministry of Agriculture, Forestry and Fisheries as ""Sweetpotato Norin No. 52"" for starch production in 2000. ""Konahomare"" is the progeny from a cross between ""Hi-Starch"" and ""Kyukei82124-1"" conducted at the Ibusuki Branch of the station in 1990. ""Hi-Starch"" has a high starch content and high yield, while ""Kyukei82124-1"" has good combining ability. Single-crossed seeds were sown in the Sweetpotato Breeding Laboratory nursery. Selection was based on field performance and starch content. ""Konahomare""exhibits moderate sprouting ability and is a prostrate plant type. The top leaves are light green. The mature leaves are green and cordate. The vine is somewhat thin with a medium internode length. There is no anthocyanin accumulation in the vein and node. The storage root is short and fusiform with light brown skin, and has a light yellowish -white flesh. The taste of the steamed root is not palatable; ""Konahomare"" is not suitable for table use. The root yield, dry matter content, and starch content of ""Konahomare"" are higher than those of ""Koganesengan"" and ""Shiroyutaka."" The starch yield is 20 to 30% higher than for ""Koganesengan"" depending on cultivation conditions. It demonstrated a 50% higher starch yield at the local agricultural experimental station than a standard cultivar undergoing long-term mulching cultivation with plastic film. ""Konahomare"" is slightly susceptible to black rot (Ceratocystis fimbriata), moderately resistant to root lesion nematode (Pratylenchus coffeae), and slightly resistant to root knot nematode (Meloidogyne incognita). The storage ability of the storage roots is somewhat low during winter.