Variety Name: Jizhangshu No.8  

乐发ll　　Characteristics: it is a medium maturing variety, and has a growth period of 93 days after seedling emergence. The plant type is upright and the growth vigor is strong. The plant height is about 93cm. The stem and the leaf are green; the main stem number of single plant is 3.4. The tuberization number of single plant is 7.17, the single tuber weight is 67.92g. The corolla is white, with few natural fruiting. The tuber sizes are evenly and are elliptic, with yellow skin and white meat, smooth potato skin and shallow bud eyes. By the analytic test of the Agriculture Product Quality Supervision, Inspection and Testing Center of the Ministry of Agriculture (Kunming), the tuber starch content is 11.80%, Vitamin C content 11.7mg/100g, protein content 3.39%, fresh potato reducing sugar content 0.121%.

Key Cultivation Techniques:

　　 1. Select same-grade healthy potato pieces for potato seeds. The weight of a potato seed is between 50g and 120g.

　　2. Direct plant the whole potato below 50g. A potato tuber above 50g should be cut into pieces. Each piece of mother tuber has 1~2 buds and the cut piece is 30~35g.

乐发ll　　3. For the cut pieces of potato seeds, use 4kg of plant ash or talcum powder or 200g of metalaxyl for each 100kg of potato seeds for the purpose of mixing, and then lay them in the house to the thickness of 10cm. Start the seeding after 24 hours.

　　4. Select the land with high water and fertilizer conditions for seeding. The suitable seeding time for Weining and other high attitude areas should be from the last ten-day of March to the beginning of April and the temperature for 10cm-deep ground maintains at 5℃. The seeding density is 3500~4000 plants/mu and base fertilizers should be enough applied.

乐发ll　　5. Star hilling and weeding when the seedling height is 15cm. Top-dress 10~15kg of urea for each mu.

乐发ll　　6. For such insect pests like aphid and Henosepilachna vigintioctopunctata, spray them with 40% rogor emulsifying oil. From the last ten-day of June to the end of August, spray metalaxyl, mancozeb and silver Farley once each 7~10 days to the harm of late blight to the potato.

　　7. Start harvesting in the mid-to-late September by artificial excavation, ploughing or a machine. No matter which way will be used, it should be gently taken and placed and gently uploaded and unloaded, without damage to the potato skin, to ensure the completeness of potato shape.