. Response of Sweet Potato Clones on Phosphorus at Different Planting
Environment around Lore Lindu National Park (Central Sulawesi). Under the direction of FRED RUMAWAS, EDI GUHARDJA, ALEX HARTANA, and IRAWATI.
Sweet potato is important food security, because it is closely related to the need of the food human population and to reduce dependence on rice and corn. Indonesian society is more
or less still dependents on tuber crops including sweet potato. However, Indonesians sweet potato yields are relatively low i.e around to 10 t/ha, whiles its potensial yield is around 40 t/ha. The development of sweet potato production is considered to be important because it is used
indirect human consumption and as an input in industry and animal feed production. Location is limiting factor to growth and production of sweet potatoes related to soil condition, temperature,
precipitation, and humidity.
The objective of this experiment is to study the response of four different sweet potato clones to four different phosphorus levels grown at three locations around Lore Lindu National
Park, Central Sulawesi. The experiment was carried out at Sidera (70 m above sea level), Ampera (600 m), and Wuasa (1100 m). Using a split plot design four P levels, (0, 100, 200, qnd
300 kg P/ha) where randomized in the four different sweet potato clones (W0331, CIP-2, CIP-3, and B0088), replicated three times at each location. Observed variables were harvest index,
fresh tuber weight, dry matter weight, lipid content, sugar content, starch content, protein content. Tuber amino acid contents were analized from bulk samples of treatments at each location. The results showed that all clones tested could growth with optimal yield by application
different level of phosphorous at different planting location and it was promising the development of those clones to fulfille carbohydrate consumption of the people around LLNP.
The fresh tuber yields of clones W0331 and CIP-2 in Wuasa and Ampera would be optimal of by application 200 kg P/ha while those of CIP-2 and CIP-3 clones at Sidera by fertilise with 100 kg P/ha.
The optimal of dry matter production was obtained by application of 200 kg P/ha for
W0331 and CIP-2 clones at Wuasa and 100 kg P/ha for CIP-3 and B0088 at Ampera and
Sidera. For optimal quality at tree location, application of 200 kg P/ha for W0331 and CIP-2 clones at Wuasa, W0331 and B0088 clones at Ampera, B0088 and CIP-2 clones at Sidera can be considered. Sugar and protein content increased with increased P applications up to 300 kg P/ha, with not interactions between clones and location. Total amino acid, and metionine contents, and the ratio metionine, total lisine and total amino acid, improved with altitude, while lisine pick at Ampera (600 m). Increasing P levels up to 300 kg P/ha increased amino acid content of the sweet potato tuber.
Key word: sweet potato, phosphorus, protein, amino acid