播期、播种深度和覆盖物对直播棉生理特性及生长发育的影响

Effects of Different Sowing Time,Sowing Depth and Covering Soil on Physiological Characteristics and Growth of Direct Seeding Cotton

为优化长江流域棉区油后直播棉栽培模式,以湖南农业大学选育的JX0010为供试材料,设置播期、播种深度和覆盖物3因素再裂区试验,分析不同栽培方式对棉花生理特性及生长发育的影响。结果表明:播期为6月.初时,棉花吐絮期的株高显著提高,而苗期NR(硝酸还原酶)和吐絮期SOD(超氧化物歧化酶)的含量降低;与4cm的播种深度相比较,播种深度为2cm时,苗期和吐絮期的可溶性糖含量、花铃期NR含量以及蕾期的株高显著提高;采用混合土覆种处理能显著提高苗期和花铃期可溶性糖含量、苗期NR含量蕾期可溶性蛋白含量、蕾期株高和花铃期果枝数,降低吐絮期MDA(丙二醛)含量;晚播条件下,蕾期的株高会随播种深度加深而降低;播期为6月.初时,随着播种深度的加深,蕾期的果枝数降低,苗期和花铃期游离氨基酸含量也降低;播期和覆盖物对花铃期脯氨酸含量的影响存在交互作用,晚播加混合土覆种处理花铃期脯氨酸含量较高。综合分析,6月初播种、采用2 cm的播种深度和混合土覆种的栽培方式能有效改善植株的生理代谢和形态指标,适用于湖南棉区油后直播。研究结果可为棉花机械化生产提供理论基础。

In order to optimize the cultivation pattern of cotton sown directly after rape harvest in the Yangtze river valley, the cotton variety JX0010 selected by Hunan Agricultural University was used as the test material in this experiment, a three factor split zone test with different sowing dates, sowing depths and covering soil was carried out to analyze the effects of different cultivation methods on the physiological characteristics and growth and development of cotton. The results showed that when the sowing date was early June, the plant height of cotton at boll opening stage increased significantly, while the NR content at seedling stage and SOD content at boll opening stage decreased, compared with the sowing depth of 4 cm, and when the sowing depth was 2 cm, the soluble sugar content at seedling stage and boll opening stage, NR content at flower and boll stage and plant height at bud stage increased significantly. The treatment of mixed soil mulching could significantly increase the content of soluble sugar, NR, soluble protein, plant height at bud stage and fruit branch number at flower and boll stage, and reduce the content of MDA at boll opening stage. Under the condition of late sowing, the plant height at bud stage decreased with the deepening of sowing depth. When the sowing date was at the beginning of June, with the deepening of sowing depth, the number of fruit branches in bud stage decreased, and the content of free amino acids in seedling stage and flower and boll stage also decreased, and there was interaction between sowing date and mulch on proline content in flower and boll stage, the proline content in flower and boll stage was higher in the treatment of late sowing and mixed soil mulching. Comprehensive analysis showed that sowing at the beginning of June, sowing depth of 2 cm and planting with mixed soil could effectively improve the physiological metabolism and morphological indexes of the plant, which was suitable for direct seeding of cotton after rape harvest in Hunan cotton area. The research results provide a theoretical basis for cotton mechanization production.