播种时期和浸种对君迁子出苗的影响     

魏素玲  张雪琴  梁臣  王小耐 《河南林业科技》2013,33(1):15-17

对君迁子(Diospyros lotus.l.)种子播前浸种和浇底水处理,于不同时期播种试验。结果表明:自然条件下,君迁子在1月底之前播种出苗较好;土壤持水量低时,播前应浸种,播种时应浇底水,可保证出苗率。君迁子种子休眠不明显,只要水分充足,4月初以前播种均可获得理想的育苗效果。  相似文献   

Sensory quality and chemical composition in carrots: A multivariate study     

Solbj⊘rg Hogstad  Einar Risvik  Kjell Steinsholt 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(4):253-264

Carrots from designed trials and organic and conventional farms were analysed for sensory quality and chemical composition. The data were combined in principal component analyses and partial least squares regression for exploration of the main factors responsible for the variation in quality. One of the most important factors was fertilization. Carrots grown with no fertilizer and carrots fertilized with 40–80 kg nitrogen ha^?1 as mineral fertilizer or 20–72 tons ha^?1of organic fertilizer contained more total sugars and total flavour strength, less crispness, crude protein, true protein and carotene, and had a lower pH, compared with carrots fertilized with 100–192 kg nitrogen ha^?1 as mineral fertilizer. Location site was also very important in the explanation of the total variation and was a composite factor of precipitation, temperature in June, growth system and length of growth period. Soil type, amount of organic fertilizer, use of pesticides and temperatures in July and August seemed to be of less importance.  相似文献   

人工栽培刺五加不同生长期不同部位矿物质的含量对比分析     

姜英  李昌禹 《特产研究》2012,34(1):55-57

采用微波消解法消解样品,以原子吸收光谱法对人工栽培的刺五加在不同生长时期及不同部位(根、茎、叶片、果实)中K、Na、Ca、Mg、Zn、Fe、Mn、Cu等8种矿物质进行含量测定.结果表明,刺五加在不同生长时期及不同部位的8种矿物质含量存在一定的差异.总的来看,不同生长时期各元素含量以夏季生长期(6月)较高,休眠期(3月)次之,生长后期(9月)为较低；不同部位8种矿物质含量除Na以外,其余7种元素含量均以叶片最高,果实次之,茎、根较低.  相似文献   

打桩振动对周围新浇混凝土的影响     

王巍 《林业科技情报》2000,(1)

质量和工期是工程的关键,构件混凝土在养生期怕震动,施工又不能等。施工场地的范围是有限的,本文通过实测,取得安全距离数据,为施工场地的布置提供了依据。  相似文献   

设计距离为7的q元BCH码的周期分布     

陈小松  王春鹏 《湖南农业大学学报(自然科学版)》2007,34(11)

通过对循环陪集的研究及利用分圆多项式的一个性质,得到了设计距离为7的q元BCH码的周期分布计算公式:码的周期分布为q的幂,当码的周期不等于某些特殊值时,幂为码长与周期的最大公因数.当码的周期为特殊值时,幂为n/b-m[6/b],这里n是码的长度,b是由n和码的周期决定的2到6之间的整数,m是q模n的指数.由此计算公式和Mobius反转公式给出了无内周期码字个数的计数结果.  相似文献   

缘毛雀麦种子发芽特性   总被引：6，自引：1，他引：5  

石凤翎  朱晓春等 《内蒙古草业》2000,(3):22-24

对不同贮藏时间的缘毛雀麦种子进行了发芽试验，明确了该种子萌发的适宜发芽条件，同时揭示了缘毛雀麦种子在15－23℃室温条件下贮藏时，种子生活力的变化规律。为缘毛雀麦种子的合理利用提供理论依据。  相似文献   

新时期政工干部的素质要求及提升途径     

孙丹蕊 《现代农业科学》2008,(10):131-131,136

政工干部在建设有中国特色社会主义的伟大实践中有不可替代的作用,主要探讨了新时期政工干部的素质要求以及如何提升政工干部素质的途径。  相似文献   

数值积分单权函数法在求算年最大降雨中的应用     

郭化文  魏Shen生 《黑龙江八一农垦大学学报》1998,10(2):9-13

简要介绍用数值积分单权函数法推求皮尔逊Ⅲ型分布参数，从而计算我国部分城市的年是大日雨量大不同重现期值，笔者认为，本文提出的数值积分单权函数法基本上能通过检验，取得精度合格的结果。  相似文献   

双低杂交油菜油研七号选育研究Ⅱ系列品种“早熟型油研七号”的选育   总被引：1，自引：0，他引：1  

侯国佐  杜才富等 《种子》1999,(6):29-31

用油研七号的不育和恢复亲本22A和821－77进行早熟性定向系统选择，育成了早熟2287A和早熟821，所配制的“早熟油研七号”（尚未审定，因需要暂用此名，下同）生育期平均提早2天，一次有效分枝数、单株有效角、千粒重等性状比油研七号分别多0.53个／株，39.6个／株和0.22g，产量比原油研七号增产3.08%。  相似文献   

Flowering, Pod Set and Reproductive Success in Soya Bean   总被引：2，自引：0，他引：2  

D. B. Egli 《Journal of Agronomy and Crop Science》2005,191(4):283-291

Much of the variation in yield of soya bean [Glycine max (L.) Merrill] and other grain crops is associated with changes in the number of pods and seeds per unit area. Photosynthesis and seed characteristics are the primary determinants of pod and seed number, but recent research suggests that the temporal distribution of flower production may also play an important role. Soya bean has a long flowering period (up to 40 days or more), but most of the flowers are produced in a much shorter time. The length of the period varies among cultivars, growth habits (indeterminate and determinate) and environments. The reproductive success of flowers produced early in the period is usually greater than those produced later. Little is known, however, of the regulation of the temporal distribution of flower production or its potential role in determining pod and seed number at maturity. Research is needed to determine first, if the temporal distribution can be manipulated to increase pod and seed set and secondly, if such increases would result in higher yields.  相似文献