四川桐油购销简史──《四川省志·粮食志》选登思宇四川是油桐的原产地之一，①主要分布在川东、川北海拔８００米以下的丘陵地带，万县、涪陵、黔江、达县、南充５地区是全川的重点产区，其产量占全省总产量８０％上下。全省桐籽常年产量１．０－１．５亿公斤，高产年达... A Brief History of Purchase and Sale of Sichuan Tung Oil ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── , Daxian, Nanchong 5 areas are the key producing areas throughout Sichuan, its output accounts for 80% of the province’s total output up and down. The province Tong seed annual output of 1.0-1.5 billion kilograms, high-yielding years ...