Key Points of High-Density, High-Yield Cultivation Techniques for Blackberry

1. Apply sufficient base fertilizer and plant at a rational density. Choose valleys or open fields with good fertility, loose soil and good drainage, and apply 1000-1500 kg of decomposed farmyard manure and 120-150 kg of superphosphate per mu, generally planting 800-900 plants per mu. For seedlings, choose plants with thick main stems, well-developed root systems, plump buds and no pests or diseases. When planting, first spread the roots flat and straight according to the shape of the seedling root system, then cover with soil, bury and firm it, and water thoroughly to settle the roots; afterward water once every 2-3 days until the plants survive.

2. Pruning after planting. Winter pruning of blackberry is very important; how well and how much it is pruned is directly related to the yield and quality of the following year. Generally leave 2-3 thick shoots per plant, and leave about 6-7 buds on each shoot at a length of about 0.4-0.6 m, cutting off the excess length to avoid consuming nutrients. After the buds sprout and grow to 10-20 cm in the second spring, leave another 2-3 thick buds on each shoot and remove all excess buds. When pruning, also pay attention to arranging branches and buds into upper and lower layers to make full use of light.

3. Management after pruning. In the south, blackberry generally begins to sprout after the Spring Festival, and at this time a “sprout-promoting fertilizer” should be applied, mainly nitrogen and phosphorus, with 10 kg of ammonium bicarbonate, 15 kg of urea and 20 kg of phosphate fertilizer per mu applied with water twice. Apply twice before and after flowering and twice during the fruit-swelling stage, with the timing controlled at twice each month. At the same time, combine with foliar feeding: spray Penbaobao, monopotassium phosphate, urea and fruit enlargement agent once every 10 days after flowering, for 3-4 consecutive sprays. In the south from late April to early May, and in the north in mid-May, when some blackberries begin to ripen and some are still flowering, stop fertilizing.

4. Blackberry has extremely strong tillering ability and numerous branches. Under dense planting, pruning away most branches can ensure that nutrients are concentrated in a small number of fruits, greatly increasing the size of the berries and achieving both dense planting and ventilation. Generally, after such pruning, the single berry weight of blackberry can reach 12-15 grams, each cluster weighs about 0.5-1.2 kg, and the yield per mu is also increased from 700-900 kg under no pruning and no dense planting to 1200-1500 kg, with very significant economic benefits.