Party leader pays visit to northern province on economic mission   Party General Secretary Nguyen Phu Trong visits the Son La hydropower plant.- VNA/VNS Photo Thong Nhat SON LA (VNS)  - Party General Secretary Nguyen Phu Trong yesterday paid a working visit to Chieng Ban Commune, Mai Son District, Son La Province, while on tour of the northern mountainous province. Trong was inspecting the implementation of socio-economic development initiatives and Party building tasks in the area. During his tour, he praised the achievements made in Chieng Ban in its new-style rural area building programme. The commune has mobilised local residents to participate in building roads and cultural houses, as well as undertaking social work. It also changed local agricultural methods by choosing to grow plants more suitable to its terrain and soil, particularly coffee, with high productivity and economic success. Locals can harvest 100,000-140,000 tonnes of fresh coffee berries per year, while registering profits more than three times higher than offered by other crops.   Party General Secretary Nguyen Phu Trong yesterday paid a working visit to Chieng Ban Commune, Mai Son District, Son La Province.-VNA/VNS Photo Thong Nhat The Party leader expressed his hope that Chieng Ban would continue increasing its productivity and quality of coffee trees to supply the domestic markets and to export products to other countries. The same day, he visited the Son La hydropower plant, where he praised the efforts by the plant's officials, engineers and workers to bring it into operation ahead of schedule. Built in 2005, the plant was put into full operation in December 2012. Since its first turbine began generating power in December 2010, the plant has produced 21.3 billion kWh of electricity, contributing over VND2.5 trillion (US$120.65 million) to the State budget. The Party leader also visits teachers and students at the province's ethnic boarding high school and offered incense to martyrs at the Son La prison relic site, where Vietnamese communist soldiers were jailed during the resistance war against the French colonialists. He also paid a visit to It Ong Commune, Muong La District, to inspect the project on growing 10,000ha of rubber trees in the province. - VNS