等行距稀植模式对杂交棉群体生长特征及产量、品质的影响

Effects of planting patterns on hybrid cotton yield,quality,and growth parameters in wide-rowspacing with sparse density

为探究等行距稀植条件下杂交棉高产稳产的生理机理,于2017—2018年在新疆兵团第七师主要植棉团场,采用大田创建高产试验示范田的方法,以鲁棉研24号稀植为研究对象,科研5号密植棉为对照,分析不同产量水平杂交棉产量构成、纤维品质、干物质积累与分配以及群体生长的影响,结果表明杂交棉等行距稀植较常规棉密植增产7.9%~24.1%,其增加的原因主要归因于单株结铃数的显著增加。进一步分析成铃空间分布发现,杂交棉等行距稀植模式下上层果枝的皮棉贡献率显著提高,上层和外围的结铃比例分别提高47.8%、76.7%,且中层的纤维马克隆值显著增加。等行距稀植模式下杂交棉的植株总干重(TDW)较常规棉密植降低18.7%~19.2%,蕾铃总干重(BDW)提高1.4%;群体生长率(CGR)、蕾铃生长率(BGR)、净同化率(NAR)无显著差异,但生殖器官质量与营养器官质量的比例(RVR)显著提高。相关分析结果表明:CGR与NAR和BGR在盛铃至吐絮期呈显著或极显著正相关,BGR与NAR在盛铃至吐絮期呈显著正相关,与RVR在盛花至盛铃后期呈极显著正相关。因此,杂交棉等行距稀植模式下,有利于充分发挥杂种优势,在保持较高群体生长速率的前提下,促进光合产物高效的向生殖器官输送,通过增加上层和外围成铃比例、提高单株结铃数来实现棉花高产稳产。

The objective of this study is to explore the physiological mechanism of high-yield hybrid cotton underequidistant low-density planting mode.The methodology is to observe the growth of Lumianyan 24 under equal spacing and sparse planting and Keyan 5 under conventional wide-narrow row with high-density planting from the year 2017 to 2018 in the main cotton field of Xinjiang Production and Construction Corps Seventh Division.The yield components,fiber property,dry matter accumulation and distribution and growth of populations were measured.The results showed that hybrid cottons under low-density planting yielded 7.9%~24.1%higher than normal cotton under high-density planting,and the main reason wasthat the former grows more bolls per plant.Further analysis on the space distribution of bolls showed that equidistant low-density planting greatly raisedthe lint contribution of upper fruiting branches,increasing upper and outskirt branches’boll rate by 47.8%and 76.7%respectively and the Micronaire(MIC)of middle bolls was greatly improved.In case of equidistant low-density planting,the hybrid cottons have 18.7%-19.2%lower TDW than regular cotton of high-density planting and 1.4%higher BDW.No obvious difference was found in CGR,BGR and NAR betweenhybrid cottons under low-density planting and normal cotton under high-density planting,but RVR of hybrid cottons under low-density planting was much higher than normal cotton under high-density planting.Relative analysis indicatedthat CGR is positively influenced by NAR and BGR during boll and bloom stage,so is BGR by NAR at the same stages and by RVR from flower to late boll stage.The conclu-sion was that equidistant low-density planting gavea full play to the advantages of hybrid cottons,facilitating the transferring of photo-synthetic product to reproductive parts,raising upper and outskirt bolls and per plant bolls without lowering the growth rate of popula-tions in result of high yields.