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1.
为提高天麻栽培产量,扩大天麻栽培地域,提高山区有限土地利用率,笔者将影响天麻田间高产栽培的几个关键因子进行比较试验,总结出天麻田间高产栽培的有效措施,为大力发展天麻生产提供了科学依据。 相似文献
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D.J. Robinson M.F.B. Dale D. Todd 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(9):921-928
Infection of potato plants with Tobacco rattle virus by its nematode vector can have different outcomes, including the development of spraing symptoms in progeny tubers. A novel syndrome described here comprises a generalized mottle in leaves on all stems, together with virtually total failure to produce daughter tubers. The outcome of infection depends partly on the potato genotype, but field trials with 15 varieties showed that the incidence and severity of spraing symptoms at three sites differed. There was no evidence that this was due to differences in virulence among the virus isolates at the sites, but it was probably the result of environmental differences that influenced the numbers and activity of the vector nematodes. At the most severely affected site, spraing symptoms were found in all varieties tested, except Record, including several that were not affected at the other two sites. Taking both severity and incidence of symptoms into account, the ranking of varieties was similar at each site. The incidence of spraing symptoms was greater in larger than in smaller tubers, and increased with later harvest dates, but did not increase when early harvested tubers were stored. Tobacco rattle viruswas detected in the roots of many of the weeds growing at one of the sites and in the roots of a few plants of the subsequent barley crop. 相似文献
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猪伪狂犬病基因缺失疫苗的制备、安全性、免疫原性、保存期测定及区域试验 总被引:3,自引:1,他引:3
为了提供有效的伪狂犬病疫苗,用鸡胚成纤维细胞扩大培养了PrV HB-98突变株(TK^-/gG^-/LacZ^+),研制了伪狂犬病基因缺失疫苗,并对该疫苗经肌肉接种、经口等免疫途径的最小免疫剂量进行了测定,同时也对4批疫苗的安全性、效力、免疫期和保存期进行了检测;同时将4批疫苗用于免疫23个猪场的母猪、新生仔猪和育肥猪进行区域试验。测定结果表明,疫苗经上述两种途径接种对不同阶段猪的最小免疫剂量均为10^5.0 TCID50;10倍免疫剂量的疫苗对初生仔猪、15日龄仔猪和妊娠母猪是安全的,免疫猪能抵抗强毒的攻击;疫苗在4℃和-20℃下分别可保存6个月和12个月。对伪狂犬病毒抗体阴性的70日龄商品猪和种猪的免疫期为6个月。田间试验表明,4批猪伪狂犬病基因缺失疫苗安全有效,并可用于仔猪发病时的紧急接种。为猪伪狂犬病基因工程疫苗的制备与应用提供了有力的依据。 相似文献
4.
张晓敏 《上海交通大学学报(农业科学版)》2015,(2):120-122
采用了文献资料法、问卷调查法、数理统计法、逻辑分析法对影响我国大学城体育场地资源共享的因素进行了分析与总结,研究结果表明,影响大学城高校体育场地资源共享的主要因素包括:场地客观因素、学校领导因素、学校教师因素、学生因素、地理位置因素、相关政策因素、课程安排因素、经济因素、社会因素、比赛安排因素。根据木桶效应,在构建大学体育场地资源共享模式的时候,需要对课程进行合理的安排,并做好场地对内和对外开放的时间以及方式合理安排,以提供我国高校体育场地资源的利用率,促进我国高等体育教育和社会体育的发展。 相似文献
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Routine agricultural practices are heavily dependent on the use of surfactants, many of which are toxic to humans and detrimental to the environment. In proof of concept work we have previously shown the potential of nanostructured liquid crystalline particles (NLCP) to safely interact with plant leaf cuticular surfaces with minimal impact on epicuticular waxes. Here we demonstrate the use of NLCP to effectively deliver the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) to plant leaves in laboratory and field studies. In the laboratory, the physiological stress responses of lupin, Lupinus angustifolius (L.) (Fabaceae) towards NLCP spray applications were shown to be much reduced in comparison with application of two common surfactants. Phytotoxicity assays of 2,4-D loaded NLCP were used to validate the herbicidal effects on Arabidopsis thaliana (L.) Heynth. (Brassicaceae) and established a similarity with that of surfactant assisted 2,4-D delivery when tested at a concentration of 0.1%. Field trials were conducted to test the efficacy of NLCP-assisted delivery of 2,4-D in comparison with commercial surfactants for the control of the invasive weed wild radish, Raphanus raphanistrum (L.) (Brassicaceae), in wheat, Triticum aestivum (L.) (Poaceae) crop fields. Compared against Estercide 800, a commercially available 2,4-D formulation, NLCP assisted delivery of 2,4-D was effective at low concentrations of 0.03% and 0.06%. The crop yield remained similar for all the tested concentrations and formulations of 2,4-D loaded NLCP and Estercide 800. This is the first report to directly show that, as an alternative to conventional methods, NLCP can be used under both laboratory and field conditions to successfully delivery an agrochemical. 相似文献
9.
R. P. O. Schulte R. Fealy R. E. Creamer W. Towers T. Harty R. J. A. Jones 《Soil Use and Management》2012,28(4):580-589
The Less Favoured Area (LFA) scheme is a major element of the EU Rural Development Policy, aimed at supporting farming in areas with natural handicaps or low soil productivity. It has been in place since 1975 and accounts for 14% of total Community funding. In 2003, the European Court of Auditors recommended that the socio‐economic criteria on which the current scheme is based be replaced by biophysical criteria. Reviews of the proposals suggest that in Atlantic climates of Northwest Europe, the new criteria do not delineate adequately areas where agricultural productivity is constrained by the biophysical environment and that such areas are instead demarcated by the occurrence of excess soil moisture conditions. In this paper, we review the impact of excess soil moisture conditions on the sustainability of farming systems and their role in constraining strategic and tactical farm management practices. In particular, we review the scientific evidence on the impact of excess soil moisture conditions on herbage growth, herbage utilization, farm operations and environmental sustainability. On the basis of this, we propose an additional biophysical criterion for the new delineation of LFAs, namely the length of time that soil water is in excess of field capacity (‘field capacity days’). While there is no clear threshold for field capacity days above which agricultural sustainability is acutely constrained, the evidence reviewed in this paper suggests that the sustainability of intensive livestock farming and tillage systems is particularly challenging in scenarios where the 80 percentile of field capacity days exceeds 220–230 days. 相似文献
10.
Sándor Hoffmann Gábor Csitári Lívia Hegedüs 《Archives of Agronomy and Soil Science》2013,59(2):141-146
There is a growing recognition for the need to develop sensitive indicators of soil quality that reflect the effects of land management on soil and assist land users in promoting sustainability of agro-ecosystems. Three soil enzymes (dehydrogenase, phosphatase and invertase) microbial biomass as biological variables and soil organic matter content (SOM) were investigated relative to fertilization and soil fertility (estimated by crop yield) at a long-term fertilization trial (Keszthely, Hungary). 0-34.7-69.4-104.1t farmyard manure (FYM) ha m 1 5 yr m 1 and the corresponding amount of mineral fertilizers (NPK) were applied in two different crop rotation systems. There were four straw and/or stalk incorporating treatments in the second crop rotation 'B'. Enzyme activities, microbial biomass and the amount of SOM were generally higher in the fertilized soils than in the unfertilized soils. The type of amendments (mineral, FYM or mixed) had significant effects only on the amount of SOM. The correlations among the biological variables and the crop yield were generally low (r < 0.250. The differences in field management resulted only in the invertase activity. 相似文献