Ji Zhangshu No. 4 (Potato)

Ji Zhangshu No. 4 was bred by sexual hybridization using Kaqiding as female parent and S.Chacoense as male parent in Bashang Agricultural Research Institute of Zhangjiakou City.

The characteristic characteristics participated in the variety comparison test in 1991, and the yield per mu was equivalent to 1947.3kg, which was 13.7% higher than that of the control Bashu 9. From 1992 to 1994, we participated in the regional trial of potato mid-ripening group in Zhangjiakou City. The average yield per mu in 3 years was 1615.2kg, which was 11.3% higher than that of Bashu 9. In 1996, the demonstration extension was 22.5 mu in Doukujiao Village, Shangyi County, with an average yield of 1473.6kg per mu, and 15 mu in Zhangming Village, Zhangbei County, with an average yield of 1357.5kg per mu, which was 12.5% higher than that of Bashu 9, the control.

The growth period is 95 to 100 days (from sowing to maturity). It is a mid-mature variety with semi-erect plant type, many branches, luxuriant plants and long flowering period. Plant height 75~80cm, flowers white, leaf blades yellowish, ovoid. Long oval potato shape, white skin and white flesh, shallow bud eyes, uniform distribution, large and medium potato rate of more than 75%. The dormancy period of tuber is about 65-70 days, generally yielding 1400~-1500kg per mu. Processing quality: reducing sugar 0.19%, anti-browning reaction insensitive, dry matter content 21.6%, crude protein 1.27%, vitamin C content 30.5mg/100g (fresh potato). Resistance: resistance to late blight, light susceptibility to leaf curl and bunchy top virus disease in late growth period. Judging from the appearance and processing quality of potato, this variety is a typical processing variety to earn foreign exchange.

Economic benefits: due to suitable processing requirements, Beijing Xinplao Food processing Co., Ltd. buys and makes French fries for special purpose, with a yield of more than 100m 150g per mu plus main potato 1000~l100kg, the price of which is 0.300.40 yuan per kilogram higher than that of general commodity potato in the market, and the income of only processed commodity potato per mu reaches 850million 1100 yuan. it is the only processing new improved variety with an annual income of more than 1000 yuan per mu in the alpine and arid area of northern Hebei. In order to ensure high yield, it has entered the stage of stem tip virus-free and batch virus-free seedling production, and the corresponding seed propagation system has been established.

Cultivator Zhangjiakou Bashang Institute of Agricultural Sciences

Regional and technical adaptability and cultivation points: it is mainly suitable for sandy soil cultivation in the first cropping areas of Hebei, Inner Mongolia, Shanxi and Northeast China. The suitable sowing date is early May, sowing quantity 125kg per mu, 3500 plants per mu, combined with sowing mu application of high quality farm fertilizer 4000kg, chemical fertilizer ammonium bicarbonate 35kg, interplanting between big and small ploughs, planting in big ploughs and chemical fertilizers in small ploughs to prevent seed burning and lack of seedlings.

Seed potato treatment: in order to increase the emergence rate, prolong the growth period and increase the rate of large and medium potato, seed potato was damaged 18 days before sowing. Seed potato was placed in a warm room of 18 ℃ ~ 20 ℃ for sprouting, and when the bud base was like mung bean, the seed was dried outside in the leeward and sunny place. Generally, the seed was dried for 7 to 10 days, turned over at any time in the process of drying, so that its photosensitivity was uniform, and sick potatoes were removed at any time, and then cut longitudinally. One to two buds are guaranteed on each sweet potato, and the weight is not less than 5Qg.

Management: rake or hoe with the word "human" at the top soil of 50% of the seedlings in time, pursue urea 15kg per mu according to the seedling potential in the budding stage, cultivate the soil 3 times during the whole growth period, strictly press the stolon strips, increase the tuber level, increase the yield per plant, strictly prevent the production of green head tuber, affect the commercial potato rate, and ensure the increase of production and value.