Introduction and Cultivation Techniques of the New Blackberry Variety 'Bausen'

Bausen is a blackberry variety introduced from the United States. In 2001, the Institute of Botany, Jiangsu Province and Chinese Academy of Sciences introduced it for trial planting, and it showed characteristics such as strong adaptability, early maturity, and good flavor. The introduction and cultivation techniques of Bausen in the Nanjing area are described below. 

Characteristics and Traits: Bausen is a large-fruited early-maturing variety; each plant has 116-167 fruit clusters, with 5-8 fruits per cluster; the fruit clusters are 9.8-17.3 cm long and 7.3-11 cm wide, the cluster stalk is 12.3-19.5 cm long, the fruit is oblong-spherical, with a longitudinal diameter of 2.6-3 cm and a transverse diameter of 2-2.3 cm; the ripe fruit is purplish-red, with a single fruit weight of 4.9-7 g, the largest fruit weight of 15 g, a thousand-fruit weight of 4.1-4.3 g, and fresh fruit yield per plant at peak production of 4.35 kg; the soluble solids content is 8.5%-11.5%, with a sweet-tart refreshing taste, suitable for both fresh eating and processing; it is drought-tolerant but not waterlogging-tolerant, and can withstand low temperatures of -15°C; fruit at 80% ripeness can be stored at room temperature for 2-3 days, and at 0-4°C for 7-10 days. This variety matures in the Nanjing area from late May to late June, about 20 days earlier than 'Hull'. 

Orchard Establishment: Choose a site with deep soil layers, far from pollution sources, and with convenient transportation to establish the orchard. For poor soil, apply sufficient organic fertilizer during plowing to improve soil fertility. The base fertilizer is best as decomposed farmyard manure, at a rate of 5000-8000 kg per mu; or apply 40-50 kg per mu of 25% ternary compound fertilizer. Before winter, dig planting holes or planting trenches at a spacing of 2 m between rows and 1.5 m between plants, and spread an appropriate amount of rice straw at the bottom of the planting holes or trenches. Before buds sprout in early spring, select 1-year-old cutting seedlings or layer seedlings for planting. After planting, water thoroughly to settle the roots. 

Trellis and Training: Set up a trellis after planting, with the espalier type being preferable. The trellis material should be over 2 m in height, requiring about 66 trellis posts per mu, with 2-3 strands of No. 12-14 wire strung on the trellis. During the growing season, guide the canes onto the trellis in time to prevent the branches and canes from tangling together. In early to mid-July, remove dead and withered canes, cut off 2-year-old old canes from the base and remove them from the orchard, and at the same time tie the 1-year-old canes onto the trellis. From early December to early February, prune off branches with pests, diseases, and frost damage, thin out weak and excessively dense branches, and appropriately shorten the remaining branches. Generally, leave 8-12 strong canes 1-1.5 m long per plant, and evenly tie them to the trellis. 

Fertilizer and Water Management: Apply topdressing 3 times according to plant growth, mainly with quick-acting fertilizers. The first application is in late March when sprouting branches emerge, mainly with nitrogen fertilizer; the second is in late April during the fruit enlargement stage, mainly with nitrogen-phosphorus fertilizer or ternary compound fertilizer; the third is in August during the flower bud differentiation stage, mainly with compound fertilizer. In winter, open a trench 60 cm from the plants to apply base fertilizer, with both trench width and depth of 20-30 cm, applying 1000-1300 kg per mu of farmyard manure or 40-50 kg per mu of 25% compound fertilizer. During summer and autumn droughts, irrigate once every 10 days, until the soil is thoroughly wet; for mulched orchards, irrigate once every 20 days. During the rainy season, drain water promptly; water must not accumulate in the orchard for extended periods. 

Pest and Disease Control: Before buds sprout in early spring, spray 3-5 degrees Baumé lime-sulfur mixture to control diseases. Stop applying chemicals 20 days before harvest to reduce pesticide residues in the fruit and ensure fruit quality.