胡椒园间作槟榔对胡椒产量及养分利用的影响

胡椒园间作槟榔是海南胡椒间作体系中应用较广的一种模式,为探明其间作优势来源,以海南胡椒优势种植区4个试验点的胡椒单作与胡椒/槟榔模式为研究对象,调查了2009~2011年各点胡椒产量与养分投入状况,测定2011年土壤养分与胡椒植株叶片养分含量,从而对比了间作模式与胡椒单作模式下胡椒产量、土壤养分状况、肥料产量贡献率和胡椒叶片养分含量的差异。结果表明：在各试验点不同产量水平下,同一地点间作模式的胡椒产量均极显著高于单作。间作模式土壤氮、磷、钾全量含量略低于单作,但未达到显著水平;间作模式土壤速效磷和速效钾含量高于单作,且速效磷差异达到显著水平。在养分投入相同的条件下,间作模式氮、磷、钾肥料偏生产力均极显著高于单作。间作模式下胡椒叶片磷、钾养分含量周年大于单作。上述结果表明胡椒/槟榔间作提高了土壤中速效养分的含量,促进了胡椒对磷、钾等养分的吸收,从而提高了其肥料利用效率,并最终提高胡椒产量。胡椒/槟榔的间作优势可能与二者地下部互作有关。     

胡椒与槟榔间作对群体养分吸收利用的影响

选用胡椒与槟榔种子苗为材料,比较胡椒与槟榔间作和二者单作条件下,胡椒与槟榔的根系形态、地上部和根系的养分浓度和含量、养分吸收和利用效率、地上部和根系生物量的差异。结果表明:胡椒与槟榔间作显著提高了胡椒根系有效形态及地上部氮、磷、钾、钙和镁的养分含量,胡椒对磷的利用效率和地上部生物量均表现出明显的间作优势。分析胡椒根系形态参数与养分效率相关关系,发现胡椒的根长密度、比根长和比表面积与磷的利用效率显著正相关,其中比根长对磷利用效率提升的贡献率达94%,胡椒/槟榔体系显著提高了胡椒的这3个根形态参数和生物量,所以,胡椒/槟榔体系通过改变胡椒根系形态,增加了对养分的吸收量和利用效率,从而提升了胡椒的生物量。间作还提高了槟榔根系氮和磷的养分含量,提高了槟榔对氮和磷的利用效率。间作体系中槟榔对氮和磷的利用效率增加,有利于提高槟榔抵抗病虫的能力,还可以改善槟榔黄化现状和防止其发生。可见,间作体系通过改变胡椒和槟榔的根形态,提升了二者对养分的吸收利用效率和胡椒生物量。     

不同氮肥施用量对胡椒生长及花穗的影响

以热引1号胡椒为材料,研究不同施氮量(0、3.5、7、10.5、14 g/株)处理对幼龄胡椒叶片SPAD值、叶片氮含量、土壤硝态氮含量、胡椒长势和花穗发育的影响及叶片氮含量与花穗发育的相关关系。结果表明:施氮量由0增加到7 g/株,胡椒叶片SPAD值、叶片氮含量均逐渐增加,促进胡椒生长。施氮量为10.5~14 g/株时,胡椒叶片的SPAD值降低,叶片氮含量减少,胡椒株高和冠幅均受到抑制,开花时间晚,花量较少,且土壤中残留的硝态氮增加。因此,在本试验条件下,幼龄胡椒适宜的施氮量为3.5~7 g/株。在生产中,除了应控制氮肥的施用量外,还应增加磷钾肥的施用。      

胡椒果实的生长规律及其在不同发育阶段的养分含量研究

对胡椒花穗、果实的生长规律和果实在不同发育阶段的养分含量进行研究。结果表明,胡椒从开花、果实生长发育到成熟,需要8一9个月。随着胡椒果实的发育膨大,果实N、P、K、Ca和Mg的含量逐渐增加,但不同养分增加幅度有所不同。胡椒果实中还含有一定的微量元素,如锰、铁、硼、铜和锌等。     

外源赤霉素调控胡椒花穗形成及增产机理

花穗数目是影响胡椒产量的关键因素之一,前人研究发现喷施赤霉素可以增加胡椒花穗数目,但是增穗机理尚不明确.为了揭示赤霉素调控植物由营养生长向生殖生长转变的机理,选用幼龄胡椒为试材,设置不同浓度赤霉素(20、40、60、100 mg/L)和赤霉素抑制剂多效唑(1500 mg/L),以清水为对照,进行喷施试验.研究测定胡椒的...     

种植年限对胡椒园土壤化学肥力指标的影响

系统探讨了不同种植年限胡椒园土壤化学肥力指标的变化状况,结果表明:随种植年限的推移,上层土壤有机质和全氮、土壤有效锰含量明显下降,有效硼与下层土壤有效铜含量明显上升,部分养分含量有下降趋势,须通过强化土壤养分管理、改进施肥方式等措施,阻止老龄胡椒园部分养分继续下降。     

幼龄橡胶树生长与叶片养分的相关性

通过分析研究幼龄橡胶树生长量与叶片养分的相关性,以实现幼龄橡胶树的养分诊断,为幼龄橡胶园的养分管理提供依据。在橡胶树定植后的第2～5年,每年9月采集叶片样品测定养分含量,同时测量橡胶树茎围与树高。在对测定结果进行相关性分析的基础上,利用多元逐步回归分析和聚类分析,研究橡胶树生长量与叶片养分的相互关系。结果表明:茎围与叶片的N、P、Mg、Fe、Cu具有显著的正相关关系,树高与叶片中的N、P、K、Ca、Fe、Cu、Zn具有显著的正相关关系;包含N和Ca的方程为橡胶树茎围的最优方程,包含N、P和Ca的方程为橡胶树树高的最优方程。通过聚类分析将橡胶树分成4种养分类型,不同类型的生长量及养分含量有明显差异,其中第4种类型茎围和树高相对较小,N、P含量也处于缺乏范围;K、Ca的含量较丰富,4种类型均处于正常范围以上;Mg的含量较低,4种类型均低于正常范围。幼龄橡胶树养分不均衡状况较显著,叶片中镁的含量整体较低,幼龄橡胶园的养分管理过程中,增加镁肥施用量的同时,还应调整不同养分间比例,以保证橡胶树的正常生长及养分间的平衡。     

橡胶与胡椒复合种植模式分析

橡胶与胡椒间作栽培模式对于推动我国热区橡胶和胡椒2大产业的发展,以及改善长期单作对土壤环境造成的不利影响具有重要理论与实践意义。综述橡胶和胡椒2种间作物的生物学和养分吸收特性,评价2种作物间作的空间资源利用、小气候环境条件和土壤资源利用的适宜性和生产效率,并对橡胶与胡椒间作栽培模式的生态效益和经济效益进行深入剖析,提出橡胶间作胡椒栽培模式存在的主要问题和橡胶用于胡椒活支柱栽培的研究重点和应用前景,为生产上橡胶胡椒间作提供依据。     

海南橡胶林落叶特征研究

以海南幼龄和成龄橡胶林为对象,采用野外凋落框收集和关联分析等方法,研究2019年5月至2020年4月海南儋州区域橡胶林落叶特征和影响橡胶落叶的主要气候因子。研究结果表明:(1)海南橡胶林落叶产量呈"双峰"型动态变化,当年7月出现小峰,翌年3月出现最高峰;翌年2—4月为集中落叶期,该时期幼龄和成龄林分别占全年落叶总产量的73.04%和70.61%;成龄林落叶产量显著高于幼龄,增幅为14.77%。冗余分析表明,月均温度与月落叶产量呈极显著负相关关系,解释度为49.9%,贡献率为58.6%;(2)幼龄和成龄林间落叶C、N、P、K、Ca、Mg含量月动态变化趋势相似,各元素含量在秋冬季呈下降趋势,而冬春季出现养分富集的现象,年均含量在成龄和幼龄林间差异不显著;(3)落叶养分归还量月动态与落叶产量动态变化相似,受落叶月产量影响较大,而归还量受落叶产量和养分含量共同影响,落叶归还量表现为C>N>K、Ca>Mg>P,成龄显著高于幼龄,各元素增幅分别为16.3%、17.1%、16.7%、27.4%、15.3%和17.7%;(4)幼龄林各元素养分利用效率总体高于成龄林,其中幼龄钾素养分利用效率显著高于成龄(P<0.05);(5)月均温度是影响2019—2020年海南儋州橡胶林落叶格局的主要气候因子。该研究成果可为海南橡胶割胶制度以及养分管理提供技术支撑。     

海南橡胶林落叶特征研究

以海南幼龄和成龄橡胶林为对象,采用野外凋落框收集和关联分析等方法,研究2019年5月至2020年4月海南儋州区域橡胶林落叶特征和影响橡胶落叶的主要气候因子。研究结果表明:(1)海南橡胶林落叶产量呈"双峰"型动态变化,当年7月出现小峰,翌年3月出现最高峰;翌年2—4月为集中落叶期,该时期幼龄和成龄林分别占全年落叶总产量的73.04%和70.61%;成龄林落叶产量显著高于幼龄,增幅为14.77%。冗余分析表明,月均温度与月落叶产量呈极显著负相关关系,解释度为49.9%,贡献率为58.6%;(2)幼龄和成龄林间落叶C、N、P、K、Ca、Mg含量月动态变化趋势相似,各元素含量在秋冬季呈下降趋势,而冬春季出现养分富集的现象,年均含量在成龄和幼龄林间差异不显著;(3)落叶养分归还量月动态与落叶产量动态变化相似,受落叶月产量影响较大,而归还量受落叶产量和养分含量共同影响,落叶归还量表现为C>N>K、Ca>Mg>P,成龄显著高于幼龄,各元素增幅分别为16.3%、17.1%、16.7%、27.4%、15.3%和17.7%;(4)幼龄林各元素养分利用效率总体高于成龄林,其中幼龄钾素养分利用效率显著高于成龄(P<0.05);(5)月均温度是影响2019—2020年海南儋州橡胶林落叶格局的主要气候因子。该研究成果可为海南橡胶割胶制度以及养分管理提供技术支撑。     

Sensitivity of Erysiphe graminis f.sp. hordei to morpholine and piperidine fungicides

Responses to a piperidine fungicide, fenpropidin, and to a morpholine, fenpropimorph, of single-colony isolates of Erysiphe graminis f.sp. hordei, collected in eastern Scotland and England in 1988, were strongly correlated. All isolates could be classified as sensitive (S) or resistant (R) to these fungicides. There was comparatively little variation in sensitivity to a second morpholine, tridemorph. Responses to tridemorph were weakly correlated with responses to fenpropidin and fenpropimorph. The levels of resistance detected were low in relation to recommended field application rates of the fungicides. Four R isolates, from north-east Scotland, had lower sensitivities to fenpropimorph and tridemorph than others in the R group, but showed similar sensitivities to fenpropidin. R isolates were frequent in Scotland, from Midlothian north to Moray, where the highly mildew-susceptible variety Golden Promise was widely grown, but were not found in England. The pattern of race-specific virulences of R and S isolates indicates that resistance to fenpropidin and fenpropimorph evolved several times, and therefore suggests that the same gene(s) causes resistance to both chemicals.     

喷灌对秦岭北麓旱地小麦产量及品质的效应

为给陕西旱地及关中灌区小麦高效灌溉提供技术支撑,在陕西秦岭北麓的蓝田县进行了小麦不同生育时期喷灌小区试验和生产示范试验,研究了喷灌对小麦产量及品质的影响。结果表明,在越冬期和拔节期喷灌可显著提高小麦产量、效益和水分利用效率,产量、收入和水分利用效率相对于无灌溉处理的增加幅度分别为22.0%~95.7%、16.5%~83.6%和9.3%~82.7%。喷灌后籽粒容重、吸水率和最大拉伸阻力分别增加1.8%~2.6%、0.5%~1.4%和0.6%~1.9%,其他品质指标降低,磨粉品质和加工品质明显变差。其中籽粒蛋白质含量和硬度分别降低5.2%~8.1%和6.0%~9.4%,最大拉伸面积、沉降值、湿面筋含量和稳定时间分别降低5.2%~7.8%、13.1%~17.3%、3.7%~7.8%和31.3%~42.4%。     

152个黄淮地区小麦主要品种(系)的多抗性鉴定

为给小麦抗病抗虫育种提供依据,于2004～2006年在山东济南对152份来自黄淮地区的小麦主栽品种(系)进行了抗小麦条锈病、叶锈病、白粉病及蚜虫鉴定.结果表明,在供试品种(系)中表现高抗条锈病的品种(系)占46.71%,中抗品种占25.66%;高抗叶锈病的品种占23.68%,中抗品种占24.34%;高抗白粉病的品种占28.29%,中抗品种占55.92%;高抗蚜虫的品种(系)占5.26%,中抗品种占13.16%.综合来看,对小麦条锈病、叶锈病和白粉病表现中抗以上的品种(系)47个,占30.92%;兼抗(中抗以上)小麦条锈病、叶锈病、白粉病和麦蚜的有5个品种(系),占3.29%.     

Recycling of sewage sludge to grassland: a review of the legislation to control of the localization and accumulation of potential toxic metals in grazing systems

The recycling of sewage sludge or biosolids to grassland is strategically important in the European Union (EU) and its use is tightly regulated to control the risk of pathogen transfer to animals and the food chain. Sewage sludges not only contain valuable concentrations of beneficial nutrients, but also elevated concentrations of potentially toxic metals (PTM) compared with average background concentrations in the soil. The EC and UK regulations refer to six PTM, Cd, Pb, Cu, Zn, Ni and Hg, with provisional regulations for Cr, that have to be controlled to prevent detrimental effects on soil and animal health. Despite these regulations, there is still a danger that grazing animals may ingest elevated concentrations of PTM. Biosolids may adhere to herbage after the surface application of sewage sludge to grassland. The repeated surface application of sewage sludge to grassland can lead to elevated concentrations of PTM at the soil surface that may be ingested, together with soil and herbage, by grazing ruminants. This may lead to accumulation of Cd or Pb in liver or kidney. The risk to the human food chain is considered to be low, but the impact on the environment is still unknown. There is little information, for example, on the amount of soil and PTMs that may become incorporated into conserved grass. At present EU and UK legislation and voluntary codes of practice have been developed to protect animal from pathogens in sewage sludge and to minimize any potential risks from accumulation of PTM. The background and implementation of the legislation are examined in this review, and the source and mechanisms of accumulation of PTM by the grazing animal are evaluated.     

以新发展理念建设现代农业强市

从坚持统筹协调以强化现代农业规划引领、坚持开放兼容以推进一二三产业融合、坚持绿色安全以加快农业供给侧改革、坚持改革创新以保障农业可持续发展、坚持合作共享以提升农业产业化经营水平5个方面阐述加快推进江门市的农业现代化建设，旨在将江门市建设成产出高效、产品安全、资源节约、环境友好的现代农业强市。     

水稻与无芒稗的竞争和化感作用

用差时播种共培法的改进方法对105份水稻、6份巴西陆稻进行了化感作用抗稗草评价。 结果表明长匡7号、P4、Kogyoku、 IR27316、 Milyang 54和巴西陆稻AJ035等材料对无芒稗有较好的化感作用。盆栽研究表明,谷梅2 号、中156对无芒稗的抑制作用显著大于对照,而化感作用材料TN1对无芒稗的抑制作用与无化感作用材料秀水63无显著差异。中156的抑制作用强与其株高有关,而谷梅2号对无芒稗的抑制作用强主要在于其本身的化感作用。随着水稻密度增加,无芒稗受抑程度加剧,化感作用水稻对稗草根部的抑制似乎要比无化感作用水稻强。TN1对无芒稗的化感作用不明显,可能是由于对不同生态的稗的作用不同之故。     

Ecological Context for Examining the Effects of Transgenic Crops in Production Systems

SUMMARY

Ecological processes can have strong effects on production systems, many of which prevent crops from reaching their maximal yield. Past and present management strategies have been developed to mitigate the negative interactions, thereby improving crop production. However, when applied to complex and variable agroecosystems, some of these strategies have resulted in unintended ecological effects that ultimately hindered production. Transgenic crops are a widespread and powerful management option, and there is a tremendous need to understand their intended ecological effects as well as potential unintended direct and indirect effects. The purpose of this review is threefold: (1) to discuss four of the major ecological effects that limit crop production: competition, herbivory, disease, and abiotic stresses, (2) to describe how biotechnology is addressing these problems, and (3) to examine the ways these biotechnological solutions may cause ecological effects that unintentionally hinder crop production. We find that, to date, there has been little diversity in the types of transgenic crops available and the approaches they use to improve crop production. Transgenic crops, like previous agricultural technologies, are designed to enhance a singular plant trait in order to solve a specific production problem. When viewed in a simplified system, transgenic crops seem to provide effective means to mitigate negative ecological effects. However, when approached via a larger ecological context, it is clear that transgenic crops have already had and will continue to have unintended ecological effects that can ultimately affect crop production through mechanisms such as gene flow, resistance evolution, community interactions, and production practices. No management option, including transgenics, is universally beneficial or detrimental. The ecological context of specific agroecosystems may improve predictions of the benefits, limitations, and consequences of a given management tactic within that system. As we increase our understanding of the ecological context of crop production problems, we may be able to improve our control efforts to maximize production and minimize potential problems in the future.     

Field evolution of insecticide resistance in the brown planthopper (Nilaparvata lugens Stål) in China

The brown planthopper (Nilaparvata lugens Stål) is one of the most destructive pests of rice crops in Asian countries including China, Vietnam, Thailand, etc. Evolution of resistance in this pest insect to isoprocarb, buprofezin, pymetrozine, imidacloprid and other neonicotinoid insecticides has been reported. In order to investigate the current status of resistance to commonly used insecticides, nine field populations of N. lugens were collected from Central China, East China and South China, and resistance to insecticides was monitored from 2009 to 2012. All the 9 field populations collected in 2012 had developed extremely high resistance to imidacloprid, with resistance ratios (RR) ranging from 209.3 to 616.6. Resistance to imidacloprid was much higher in 2012 than in 2009. The RR of thiamethoxam varied from 17.4 to 47.1, and the RR of nitenpyram varied from 1.4 to 3.7 in 2012. Of the 9 field populations, six populations showed higher resistance to nitenpyram in 2012 than in 2011. RR for buprofezin varied from 110.1 to 221.6 in 2012 whereas resistance was at a medium level (RR 20.4 ∼ 39.4-fold) in 2009. RR for pymetrozine ranged from 34.9 to 46.8 in 2012. As for isoprocarb, RR ranged from 21.7 to 38.1 in 2012. The obvious increase in resistance to widely applied insecticides indicates that insecticide resistance management strategies are urgently needed to prevent or delay further increase of insecticide resistance in N. lugens.     

贵州主栽杧果品种果实品质及香气成分分析

为了解贵州主栽杧果品种的果实品质特性,分析了‘金煌杧’‘贵妃杧’‘玉文杧’‘桂七杧’‘红玉杧’5个主栽杧果品种果实的12个品质指标和香气成分。结果表明：5个杧果品种的平均单果重在380~898 g,果形指数在1.60~2.14,可食率72.10%~77.74%,水分含量82.06%~85.10%,总灰分含量1.30%~1.70%,粗纤维含量在0.90%~1.10%,可溶性糖含量在7.75~13.90 g/100 g,可溶性固形物含量在11.05%~17.10%,总酸含量在0.120~0.233 g/100 g,维生素C含量在0.0018~0.0073 g/100 g,糖酸比在40.26~123.88,固酸比在61.30~153.39;5个杧果品种共检测出50种香气成分,以萜烯类化合物为主;‘金煌杧’‘贵妃杧’‘玉文杧’‘桂七杧’‘红玉杧’分别检测出香气组分14种、14种、21种、21种、16种,其中萜烯类化合物的含量分别达56.34%、73.95%、82.47%、97.32%、64.16%。5个杧果品种的香味均以松木香味为主,略带青香、苹果香和柠檬香等香味。     

广西沿海地区豇豆健身控害技术途径

根据广西沿海地区豇豆生长发育气候环境条件和病虫发生为害特点,提出通过创造有利于豇豆正常生长发育而不利于病虫发生为害的栽培环境条件,有效地改善豇豆生育状况,使植株健壮生长,增强自身抗逆性,减少、控制病虫滋生、蔓延和为害,控制豇豆产品农药残留不超标,实现豇豆健身栽培。