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991.
992.
四合木种子特性的测定研究 总被引:12,自引:0,他引:12
本文就蒺藜科的四合木种子进行了千粒重,吸水增重率,发芽率,生活力,活力五项测定,并分析了测定结果与方法,得出了很有价值的结论。 相似文献
993.
A. F. Ibrahim H. R. El-Wekjl Z. R. Yehia Sh. A. Shaban 《Journal of Agronomy and Crop Science》1988,160(5):319-324
Two field experiments were carried out during 1984 and 1985 seasons at the Farm of Shandaweel Agric. Res. Station, A. R. C, Ministry of Agric. (Egypt), to study the effect of five herbicides applied as a single or in tank mixtures as well as hoeing treatment on sesame plants and dominated annual weeds under Upper Egypt growing conditions. The herbicides alachlor at 2.304, pendimethalin at 2.040, linuron at 1.200, diuron at 0.960 and prometryn at 1.920 kg a.i./ha were applied preemergence as a single herbicides, as well as alachlor and pendimethalin combined with linuron, diuron or prometryn at the same rates. Two checks were included, one was left without weed removal, while the other was hand-hoed.
Pendimethalin at 2.040 applied alone or in mixtures with linuron at 1.200 or with diuron at 0.960 kg a.i./ha gave the best grass weed control, while excellent effectiveness against annual broad-leaves was obtained by linuron at 1,200 and diuron at 0.960 kg a.i./ha alone or in mixtures with pendimethalin at 2.040 kg a.i./ha. Whereas, pendimithalin at 2.040 applied alone or in tank mixtures with linuron at 1.200 or with diuron at 0.960 kg a.i./ha gave the best control for total annual weeds and higher seed yield of sesame as well as other yield contributing characters. 相似文献
Pendimethalin at 2.040 applied alone or in mixtures with linuron at 1.200 or with diuron at 0.960 kg a.i./ha gave the best grass weed control, while excellent effectiveness against annual broad-leaves was obtained by linuron at 1,200 and diuron at 0.960 kg a.i./ha alone or in mixtures with pendimethalin at 2.040 kg a.i./ha. Whereas, pendimithalin at 2.040 applied alone or in tank mixtures with linuron at 1.200 or with diuron at 0.960 kg a.i./ha gave the best control for total annual weeds and higher seed yield of sesame as well as other yield contributing characters. 相似文献
994.
D.?A.?ShahEmail author N.?Pucci A.?Infantino 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(1):13-21
The incidence of seed infection by fungal species pertinent to the fusarium head blight complex was monitored from 1999 to 2002 in two soft and three durum wheat cultivars grown across the northern, central and southern production zones of Italy, in order to characterize the species composition at the seed level. The main species recovered were Fusarium graminearum, F. poae and Microdochium nivale. There was a marked influence of production zone on seed infection incidence for both durum and soft wheat cultivars, with incidence of infection generally decreasing from the northern to the southern zone. Incidence of seed infection by different species of Fusarium was twice to four times higher in durum compared with the soft wheat cultivars in the study. There were no significant differences in terms of seed infection incidence between the two soft wheat cultivars, but the durum cultivars differed in their levels of seed infection for some of the pathogens. The results demonstrated that the durum cultivars were more at risk of seed infection by pathogens associated with fusarium head blight, and that wheat grown in northern Italy is at higher risk of seed infection by these species. 相似文献
995.
K.?N.?Amruthesh N.?P.?Geetha H.?J.?Lyngs J?rgensen E.?de?Neergaard H.?Shekar Shettyappbot@sancharnet.in" title="hss_uom@hotmail.com appbot@sancharnet.in" itemprop="email" data-track="click" data-track-action="Email author" data-track-label="">Email author 《European journal of plant pathology / European Foundation for Plant Pathology》2005,111(2):125-137
Downy mildew of pearl millet, caused by Sclerospora graminicola, is a devastating disease, resulting in high economic losses in the semi-arid regions of the world. Recently, induction of host plant resistance using biotic and abiotic inducers are included among disease management practices as an eco-friendly approach. Unsaturated fatty acids are considered as a new generation of plant disease resistance inducers. In the present study, six unsaturated fatty acids, viz. docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), arachidonic acid (AA), linolenic acid, linoleic acid and oleic acid, all originally detected in the zoospores of
S. graminicola,were applied to seeds of susceptible cultivars of pearl millet to examine their ability to protect against downy mildew under greenhouse and field conditions. In greenhouse experiments, EPA and AA induced a maximum of 78.6% and 76.5% protection, whereas linoleic acid, DHA and linolenic acid provided up to 66.3%, 61.2% and 24.5% protection, respectively. Oleic acid was not effective in protecting pearl millet (only 5.1% protection). A time interval of four days between treatment of seeds and challenge inoculation was required to obtain optimum protection. Plants raised from treated seeds and challenge inoculated at the tillering and inflorescence stages showed enhanced resistance, resulting in higher grain yield compared to untreated plants of the same cultivar. Chitinase activity was found to be higher in susceptible seedlings of pearl millet after treatment with the fatty acids and pathogen inoculation than in seedlings only inoculated with the pathogen. This indicates that host defence responses are activated and thus that induced resistance is involved in the protection observed. The role of unsaturated fatty acids as activators of resistance against downy mildew in pearl millet is discussed. 相似文献
996.
997.
水分是影响青皮(Vatica astrotricha Hance)种子活力最关键的内在因素,其中种胚含水量是决定因素。用含水量27—29%椰糠控制种胚含水量在50—52%,也就是控制种子含水量在30—36%,维持种子一定的呼吸强度(32℃下测定为50—60 O_2μl/g·h),种子活力保持最高,能延长寿命。找出了储藏中种子安全含水量的最佳点,此点处于安全含水量下限的内缘,可利用种子本身果翅与种子或大小种子之间含水量的内在关系来测定。这种测定方法准确、快速又简便。可考虑作为确定“顽拗型”种子安全含水量下限的新捷径。 相似文献
998.
温度、光照和发芽床对假俭草种子萌发的影响 总被引:3,自引:0,他引:3
实验室内进行了假俭草种子净度检验样品最低限量和发芽检验方法的研究,探讨了光照(以黑暗为对照)、温度(分别包括20℃恒温,15/25℃、20/30℃、20/35℃和25/35℃变温)和发芽床(分设纸上TP和砂中S)等因素对种子发芽的影响。结果表明:假俭草种子净度检验样品最低限量是3g,送验样最低量以及计数其它植物种子检验样品最低量均为30g;最佳萌发条件为20/30℃或20/35℃变温(16小时低温,8小时高温),高温时段设光照,和纸上(TP)发芽;发芽的初次和未次计数时间分别以第10天和第21天为宜;种子的幼苗发育可划分为单子叶植物子叶留土类型。 相似文献
999.
中国东北部针叶林种实害虫调查报告 总被引:2,自引:0,他引:2
本文是1987年7—8月中法联合调查中国东北部针叶树种实害虫的初步结果,所调查地区有:黑龙江省小兴安岭的五营自然保护区、丰林林业局的母树林、东北林业大学凉水自然保护区;内蒙古大兴安岭的乌尔旗汗和库都尔人工,天然落叶松母树林以及黑龙江省植物园和东北林业大学哈。尔滨林场所调查树种有:兴安落叶松、红松、樟子松、黑松、红皮云杉、鱼鳞云杉及白皮冷杉。在球果内共发现15种害虫及其被害状,其中最主要的为害落叶松球果的Lasiomma属种类,落叶松球果被害率可达42—95%;其次是落叶松球果小卷蛾,球果被害率达6—2O%;第三位是球果螟,球果被害率达4—8%。 还发现冷杉球果花蝇[L.abietis(Huckett)]和冷杉球果小卷蛾(Barbara herrichiana Obraztsov),它们是我国的新记录。 相似文献
1000.
不同产地杉木种子游离氨基酸含量的初步分析 总被引:3,自引:1,他引:2
不同产地杉木种子均含有17种游离氨基酸,这与其它种子所含游离氨基酸种类基本一致。不同产地杉木种子游离氨基酸总量的变异趋势不同于杉木种子形态及发芽率的变异趋势。但其中某些氨基酸的变异趋势与种子发芽率呈负相关,表明杉木种子的发芽率可能与种子所含的某些游离氨基酸有关。不同产地杉木种子游离氨基酸总含量与干湿度指数呈负相关,说明杉木种子游离氨基酸总含量的地理变异亦可能是气候的差异所引起。 相似文献