不同种植模式对烤烟根系和叶片衰老特性的影响

以烤烟品种K326为试材，采用大田试验研究了广东南雄地区不同种植模式（单行种植+前期垄体覆盖地膜、单行种植+前期垄体覆盖地膜+后期垄体覆盖稻草、双行凹垄种植+前期垄体覆盖地膜和双行凹垄种植+前期垄体覆盖地膜+后期垄体覆盖稻草）对烤烟根系和叶片衰老特性，以及烤后烟叶经济性状的影响.结果表明：与其他种植模式相比，双行凹垄种植+前期垄体覆盖地膜+后期垄体覆盖稻草处理显著促进了各时期烤烟根系生长，根系活力提高；叶片叶绿素含量和保护酶(SOD、POD)活性均较高，而MDA含量较低，烤后烟叶的产量、产值、均价和上等烟比例等经济性状均显著高于其他处理.双行凹垄种植+前期垄体覆盖地膜+后期垄体覆盖稻草处理可以改善烤烟根系和叶片衰老特性，提高烤后烟叶经济性状，是广东南雄地区优质烟叶生产的有效种植模式.

Effects of different planting patterns on the senescence characteristics of flue-cured tobacco roots and leaves

With flue-cured tobacco (Nicotiana tabacum) cuhivar 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 mulching 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 fluecured tobacco leaves in Nanxiong tobacco-growing area of Guangdong Province.