不同下垫面对土壤热状况和出笋期的影响

通过对不同下垫面（自然裸露、尼龙薄膜覆盖、稻草覆盖）竹林地土壤温度的连续观测，分析了冬季土壤热状况的时空变化规律，比较了不同下垫面对土壤热状况的影响，建立了自然裸露和覆盖处理之间土壤温度变化的数学关系式，认为稻草覆盖的保温效果最佳，并在低温条件下更加明显．同时，观测了不同下垫面对出笋期的影响     

Year-to-Year and Maturity Variation in Rainfed Soybean Yield by Planting Dates

The interactions on rainfed soybean yield among planting date,maturity,and year-to-year climate change were studied using CROPGRO-soybeanmodel.Simulations were based on 19 planting dates,maturity groupsⅢ,Ⅳ and V,30 years recorded weather data from Corbin,Suffolk,West Point in Virginia,USA.Yield was similar on early plantings and went down with late plantings.Both grand and year-to-year variation of soybean yield declined linearly with planting date.Year-to-year climate variation was dominant yield variation source in rainfed soybean production.Interaction occurred between planting date and maturity.Optimal planting dates for different sites lied within 130th-170th day of a year.Irrigation is recommended for profitable crops,especially in Corbin and West Point.     

不同播期和秧龄对机插秧全生育期及产量形成的影响

采用双因素随机区组设计方法,以水稻品种黄华占为试验材料,分析在机插秧栽培模式下,不同的播期、插期组成的四种秧龄组合对产量性状和叶龄发生规律的影响。结果表明,随着播期和插期的推迟,产量水平呈下降趋势,其中以35d为最适秧龄,返青快、产量最高;且随着播期推迟,主茎叶片有减少趋势。     

开花期和果枝部位对短季棉纤维品质及超分子结构的影响

 利用中棉所 16研究了开花期和果枝部位对棉纤维品质与棉纤维超分子结构各项参数动态变化的影响。研究表明 ,棉纤维长度、细度、成熟度及棉纤维强度等品质性状均随开花期推迟温度降低逐渐变差 ,相同开花期条件下果枝部位对棉纤维品质性状有一定影响 ,呈现出下部棉纤维品质略高于上部的趋势 ,但不显著。前期开花较早温度较高时下部果枝的超分子结构参数呈现出优于上部的趋势 ,与下部果枝的棉纤维品质略高于上部相一致 ,但果枝部位的影响并不能改变由于开花期推迟温度降低而对棉纤维超分子结构所产生的影响。     

不同播期对油菜品种中双9号农艺性状和产量性状的影响

探索油菜品种中双9号在江汉平原的最佳播期,完善高产配套技术。采用随机区组设计研究了不同播期对中双9号农艺性状及产量构成因素的影响。随播种期的推迟,鲜重、株高、茎粗、单株总角果数和每角果粒数都相应减少;单株实际产量和单株总有效角果数存在一定的关系,不同播种期间产量存在差异;单株产量与单株总有效角果数、一次分枝数、一次分枝角果数、株高极显著正相关,与主花序角果数显著正相关。单株总有效角果数与主花序角果数、一次分枝数和一次分枝角果数均呈显著正相关。一次分枝角果数与株高存在显著正相关,与一次分枝数极显著相关。春节前较长的营养生长期是中双9号高产的关键。江汉平原中双9号适宜的播期在9月15日左右。     

盆栽大丽花的花期控制研究

探讨了影响大丽花开花的若干因素。在试验中利用扦插不定芽来繁殖种苗,采取盆栽独本大丽花的方式,分别于5年里的3月至10月间对63个大丽花品种的花期控制进行了研究。将大丽花按开花先后分为早花、中花、晚花三个品种类群;并运用全息生物学基本原理对取自根颈不同部位插穗所繁殖时后代的开花情况进行了分析;确定了营养水平会给大丽花花期早晚带来重要影响。从而总结出控制大丽花开花的具体措施,使其成品出圃率从50%左右提高到80%左右,显著增加了盆栽大丽花的观赏、商品价值。     

The Variation ofβ-glucan and Protein Content in Barley as Affected by Agronomic Practices

The influences of N applicationrate, timing, sowing date and seeding rate on β-glucan and protein content in barley grains were studied through the field experiments in Hangzhou, China during 1997 -2001. Protein content increased with N application rate and with N proportion applied at late stage. β-glucan content also responded significantly to N application rate and timing, but with different pattern with protein content. Of three N rate treatments, the medium N rate (135 kg ha-1) had the highest β-glucan content, being significantly higher than low N rate (90 kg ha-1) and no difference with high N rate (180 kg ha-1). Among three N timing treatments, two times of N top-dressing at both tillering and booting stage had significantly higher β- glucan content than once N top-dressing at tillering or booting stage. Sowing date has the dramatic effect on both β-glucan and protein content. Protein content decreased with the delayed sowing, and kernel weight showed opposite tendency. Either earlier or later sowing caused increased β- glucan content relative to sowing in early November, which is the normal date for barley sowing locally. Seeding rate had no significant influence on both β- glucan and protein content.     

云南割手密(Saccharum spontaneum L.)的研究 Ⅰ.抽穗期与海拔高度的关系

 对71个割手密材料、原生长地点海拔高度和集中种植后的抽穗期,进行相关系数的测定,呈现显著的负相关,r=-0.725,p<0.01.说明割手密抽穗期的早迟,是对生态环境长期适应的结果,是遗传性的表现.测定回归系数,b=-0.0306,经t测验,p<0.01,达极显著水平,表明海拔每降低100米,其抽穗期延长3.06天.     

GPS单频接收机在长输管道测量中的应用

目前国家测量控制点已被严重破坏，不能满足长输管道首级控制测量的要求，常规控制是以三角形构成的锁、网组成，用这种方案进行长输管道测量的首级控制时，工作量大，费用高，且控制网的推进速度慢。为此提出了用ＧＰＳ单频接收机进行长输管道测量的首级控制，搜集并整理了大量的ＧＰＳ网数据，进行了多种方案的计算，对结果进行了分析，总结出ＧＰＳ单频机用于输管道测量首级控制的方案，使原有的单频卫星定位接收机发挥了更大作用