RESUMEN
With flue-cured tobacco (Nicotiana tabacum) cultivar K326 as test material, a field experiment was conducted at Nanxiong area of Guangdong Province in 2008 to study the effects of four planting patterns, i.e., single-row ridge + film mulching at early stage, single-row ridge + film mulching at early and late stages, double-row concave ridge + film mulching at early stage, and double-row concave ridge + film mulching at early and late stages, on the senescence characteristics of its roots and leaves, and the economic traits of its leaves. Comparing with other three planting patterns, double-row concave ridge + film Aulching at early and late stages promoted the root growth of test cultivar during its whole growth period, with the root vigor increased significantly. Meanwhile, the leaf chlorophyll content and protective enzymes (SOD and POD) activities were higher, and the MDA content was lower. The leaf yield, output value, average price, and the proportion of superior leaves were also higher. Double-row concave ridge + film mulching at early and late stages alleviated the senescence characteristics of roots and leaves, and improved the economic traits of flue-cured tobacco leaves, being the efficient planting pattern to product high-quality flue-cured tobacco leaves in Nanxiong tobacco-growing area of Guangdong Province.