Two new potato varieties passed national approval

The potato varieties 'Zhongda 1' and 'Zhongshu 3' passed the approval of the National Crop Variety Approval Committee in 2005.

'Zhongda 1' is a medium-late maturing, high-starch processing variety jointly bred by the Institute of Vegetables and Flowers of the Chinese Academy of Agricultural Sciences and the Daxing'anling Regional Agricultural Science Research Institute, with a growth period of about 103 days after emergence. The plant type is erect, plant height 61 cm, stems green with a triangular cross-section, leaves green with flat leaf margins, compound leaves medium-sized, corolla white, weak natural fruit-setting ability. Tubers are oblong, light yellow skin and light yellow flesh, smooth skin, shallow eyes, marketable tuber rate 70.5%. Medium branching, long tuber dormancy period. Field performance shows resistance to late blight and slight susceptibility to mosaic virus disease. Indoor inoculation identification: highly resistant to severe mosaic virus disease, moderately resistant to mild mosaic virus disease, highly susceptible to late blight. Tuber quality: crude starch content 18.5%, vitamin C content 14.1 mg/100 g fresh tuber, reducing sugar content 0.5%, crude protein content 2.36%.

From 1996 to 1997, it participated in the national potato variety regional trial for medium-late maturing varieties in the Northeast group, with an average tuber yield of 1471 kg per mu, an increase of 33.86% over the control variety Kexin 2. In the 2004 production trial, the average tuber yield was 1457 kg per mu, a decrease of 9.1% compared with the control variety Kexin 2; the average starch yield was 275.5 kg per mu, an increase of 14.6% over Kexin 2.

Take the tubers out of storage one month before sowing, sprout and sun the seed tubers, and sow in mid-to-late April and early May when the 10 cm soil layer has steadily passed 8°C. It prefers fertilizer and water and is not tolerant of drought; choose sandy loam, black soil and other well-drained plots for planting, sow by dibbling on ridges, with a planting density of 4000-4500 plants per mu. According to the local production level, appropriately increase the application of organic fertilizer and apply chemical fertilizer reasonably; generally apply 10 kg pure nitrogen fertilizer, 4 kg pure phosphorus fertilizer and 22 kg pure potassium fertilizer per mu. During the growth period, earth up in time; from late July to late August, pay attention to the control of late blight; cut the vines in mid-September, and harvest on a sunny day 10 days after cutting the vines.

Suitable for planting as a medium-late maturing starch processing variety in Heilongjiang, eastern Inner Mongolia, Jilin and Liaoning.

'Zhongshu 3' is an early maturing variety bred by the Institute of Vegetables and Flowers of the Chinese Academy of Agricultural Sciences, with a growth period of about 67 days after emergence. The plant type is erect, plant height about 50 cm, about 3 main stems per plant, stems green, leaves green, few hairs, leaf margins wavy. The peduncle of the inflorescence is green, corolla white, stamens orange-yellow, stigma 3-lobed, natural fruit-setting. Tubers are oval, light yellow skin and light yellow flesh, smooth skin, few and shallow eyes, 5.6 tubers per plant, marketable tuber rate 80%-90%. Seedling growth vigor is strong, branches and leaves are luxuriant, stolons are short, response to day length is insensitive, tuber dormancy period is about 60 days, and it is storage-tolerant. Field performance shows resistance to mosaic virus disease and no resistance to late blight. Indoor inoculation identification: resistant to mild mosaic virus disease, moderately resistant to severe mosaic virus disease, not resistant to late blight. Tuber quality: dry matter content 19.1%, crude starch content 12.7%, reducing sugar content 0.29%, crude protein content 2.06%, vitamin C content 21.1 mg/100 g fresh tuber, excellent steaming quality.

From 1996 to 1997, it participated in the national potato variety regional trial for early maturing varieties, with an average yield of 1501 kg per mu, an increase of 39.9% over the control Zhengshu 4. In the 2004 production trial, the average yield was 1796 kg per mu, an increase of 27.84% over the control Dongnong 303.

Choose plots with loose soil and convenient irrigation and drainage; avoid continuous cropping and do not rotate with other Solanaceae crops. Plant densely in flat cultivation or intercrop/relay crop with crops such as corn and cotton. Sprout the seed tubers before sowing, apply sufficient base fertilizer, strengthen early-stage management, apply little topdressing, earth up and cultivate in time, promote early plant development and early tuber setting, irrigate in time during the tuber-setting stage and tuber bulking stage, prevent excessive vegetative growth of stems and leaves in the later stage, and stop irrigation one week before harvest. In double-cropping regions, sow from January to mid-to-late March in spring; sprout before sowing, and sowing can be appropriately advanced with plastic film mulching; in autumn, sow whole tubers from early-to-mid August to early September; before sowing, soak in 5 ppm gibberellin aqueous solution for 5-10 minutes, then cover with moist sandy soil to sprout, to prevent tuber rot, and harvest from late October to early December. The density is 4500-5000 plants per mu; for seed production fields, the density is 6000-6500 plants per mu. For seed production in double-cropping regions, harvest appropriately early in spring and sow appropriately late in autumn, pay attention to timely spraying to control aphids, and strictly eliminate diseased, mixed and inferior plants. In areas where late blight occurs frequently, strengthen control work.

Suitable for planting in spring and autumn in the double-cropping regions of Beijing, Shandong, Henan, Zhejiang, Jiangsu and Anhui.