Study on Site-specific Nutrient Management in Cotton Field     

YANG Li-ping  Jiang Cheng  JIN Ji-yun  ZHANG Feng-ming 《中国农业科学(英文版)》2001,(1):102-106

The study on the characteristics of spatial variability of soil nutrients and fertilizer recommendations in cotton field under certain conditions of agricultural management was conducted with GIS and systematic approach for soil nutrient constrains. The results showed that of the spatial variability of soil nutrient was greatly related to the management condition of previous crops. Grid sampling and variable rate application technology (VRAT) were the tools that would hopefully increase fertilizer efficiency. The fertilizers were applied where they were needed and at proper rate. Balance fertilization demonstration showed that fertilizer recommendations according to the available nutrient level in soil could decrease fertilizer cost with 657.4 yuan / ha and increase seed cotton yield by 19.8%. A net profit of the balanced fertilization was 5314.9 yuan / ha higher than that of local fertilization practice.  相似文献   

Interactions between crop biomass and development of foliar diseases in winter wheat and the potential to graduate the fungicide dose according to crop biomass     

《Crop Protection》2016

Foliar pathogens such as Zymoseptoria tritici and Puccinia striiformis causing septoria leaf blotch and yellow rust respectively can cause serious yield reduction in winter wheat production, and control of the diseases often requires several fungicide applications during the growing season. Control is typically carried out using a constant fungicide dose in the entire field although there may be large differences in crop development and biomass across the field. The objective of the study reported in this paper was to test whether the fungicide dose response curve controlling septoria leaf blotch and other foliar diseases in winter wheat was dependent on crop development and biomass level. If such a biomass dependent dose response was found it was further the purpose to evaluate the potential to optimize fungicide inputs in winter wheat crops applying a site-specific crop density dependent fungicide dose. The study was carried out investigating fungicide dose response controlling foliar diseases in winter wheat at three biomass densities obtained growing the crop at three nitrogen levels and using variable seed rates. Further the field experiments included three fungicide dose rates at each biomass level, an untreated control, and 75%, 50% and 33% of the recommended fungicide dose rate and the experiments were replicated for three years. Crop biomass had a significant influence on occurrence of septoria and yellow rust with greater disease severity at increasing crop biomass. In two of three years, the interaction of crop biomass and fungicide dose rate had a significant influence on disease severity indicating a biomass-dependent dose response. The interaction occurred in the two years with high yield potential in combination with severe disease attack. If the variation in crop density and biomass level obtained in the study is representative of the variation found cultivating winter wheat in heterogeneous fields, then there seems to be scope for optimizing fungicide input against foliar diseases site-specific adapting the dose according to crop density/biomass.  相似文献   

Remote sensing of biotic and abiotic stress for irrigation management of cotton     

Nyland R. Falkenberg  Giovanni Piccinni  J. Tom Cothren  Daniel I. Leskovar  Charlie M. Rush 《Agricultural Water Management》2007

The applicability of commercially available remote sensing instrumentation was evaluated for site-specific management of abiotic and biotic stress on cotton (Gossypium hirsutum L.) grown under a center pivot low energy precision application (LEPA) irrigation system. This study was conducted in a field where three irrigation regimes (100%, 75%, and 50% ET_c) were imposed on areas of Phymatotrichum (root rot) with the specific objectives to (1) examine commercial remote sensing instrumentation for locating areas showing biotic and abiotic stress symptomology in a cotton field, (2) compare data obtained from commercial aerial infrared photography to that collected by infrared transducers (IRTs) mounted on a center pivot, (3) evaluate canopy temperature changes between irrigation regimes and their relationship to lint yield with IRTs and/or IR photography, and (4) explore the use of deficit irrigation and the use of crop coefficients for irrigation scheduling. Pivot-mounted IRTs and an IR camera were able to differentiate water stress among irrigation regimes. The IR camera distinguished between biotic (root rot) and abiotic (drought) stress with the assistance of groundtruthing. The 50% ET_c regime had significantly higher canopy temperatures than the other two regimes, which was reflected in significantly lower lint yields when compared to the 75% and 100% ET_c regimes. Deficit irrigation down to 75% ET_c had no impact on lint yield, indicating that water savings were possible without reducing yield.  相似文献   

麦秸还田及氮肥管理技术对水稻产量的影响   总被引：31，自引：0，他引：31  

徐国伟  吴长付  刘辉  王志琴  张敏  杨建昌 《作物学报》2007,33(2):284-291

以水稻武香粳14和扬粳9538为材,大田设麦秸还田与不还田、不施氮肥、习惯施肥法（FFP）和基于叶绿素仪(SPAD)测定值的氮肥管理(SSNM)等处理。结果表明,SSNM较FFP氮肥施用量减少40.0%~41.7%,而产量平均增加3.81%。秸秆还田的较秸秆未还田的产量平均增加2.49%。氮肥的农学利用率、吸收利用率和生理利用率均以秸秆还田高于秸秆不还田处理。与秸秆未还田或FFP相比,秸秆还田和SSNM降低了生育前期的分蘖数、叶面积指数和干物质积累（但抽穗及以后差异较小）;提高了茎蘖成穗率、结实期叶片光合速率和根系活力。说明秸秆还田和SSNM有利于生育后期群体光合生产和提高物质生产效率。秸秆还田和实地氮肥管理提高了氮收获指数和氮肥利用效率。对秸秆还田和SSNM的产量、生育特性及氮肥利用效率进行了讨论。  相似文献   

向日葵茎溃疡病菌RPA检测方法的建立     

乾义柯  魏霜  黄法余  陈永青  陈卫民 《植物检疫》2021,(2):39-43

向日葵茎溃疡病菌(Diaporthe helianthi)是我国进境植物检疫性病原真菌.本研究针对D.helianthi的cal基因保守序列设计特异性引物,建立该病菌的重组酶聚合酶扩增检测技术(RPA)方法,并对其特异性、灵敏度及适用性进行评价.结果 显示,建立的RPA方法特异性强,只有3个D.helianthi样品能...  相似文献   

空间变异在土壤性质长期定位观测及取样中的应用   总被引：14，自引：1，他引：14  

姜勇  庄秋丽  梁文举  施春健  欧伟 《土壤通报》2005,36(4):531-535

通过对中国科学院沈阳生态实验站30m×42m样地进行网格法分层取样,采用经典统计学与地统计学相结合的方法,以土壤pH和有机碳(TOC)为例,探讨了空间变异在土壤性质定位试验及取样中的应用。结果表明,49对样本的pH和TOC变异系数均小于10%,变量在0~10cm和10~20cm两个层次的基本统计数值基本接近,最佳理论模型的参数显示各变量空间变异主要受结构性因素的影响,且以135°方向的变异为主;相对误差为10%时采集6个和10个土样可分别达到95%和99%的置信水平,结合空间分布格局可以确定更为精确的取样方案;综合分析表明待选样地可以作为土壤性质长期定位观测试验用地。  相似文献   

一种基于RPA的番茄褪绿病毒检测方法     

宋建  薛俊  孙海波  王姝  金凤媚 《植物保护》2020,46(4):168-170

番茄褪绿病毒Tomato chlorosis virus(ToCV)引起番茄褪绿病毒病,给番茄生产造成严重危害。开发快速准确的检测方法对该病害的防控具有重要意义。利用番茄褪绿病毒外壳蛋白(CP)基因序列,设计特异性引物,建立了ToCV的重组酶聚合酶等温扩增(recombinase polymerase amplification, RPA)检测方法,同时分析了该方法的灵敏度和特异性。结果表明,建立的ToCV-RPA方法在38℃恒温下40 min可从ToCV阳性的番茄样品中扩增出246 bp的特异性条带。扩增时间短,对设备要求低,且与番茄其他病毒无交叉反应,特异性好,灵敏度可达到PCR方法的10倍,适用于ToCV的快速检测。  相似文献   

一对等位基因互作控制的核雄性不育性     

李新奇  赵昌平 《分子植物育种》2006,4(2):289-292

通过遗传工程能够产生由两个基因共同作用而形成的雄性不育。一个可以是能够导致雄性不育的基因,另一个可以是该雄性不育基因的活化基因,它们共同存在的时候表现雄性不育。利用位点特异性重组和转基因技术能够将这两个基因安排在植物同源染色体的相同位置上表达,成为等位基因,而获得分别只具有其中一个基因的两转基因系。它们之间杂交,F1中两个基因同时存在,F1产生雄性不育而成为不育系。常规品系与此F1不育系杂交,在杂种植株中,这两个基因不能同时存在,所有植株育性恢复。利用光温敏核不育性,化学杀雄和人工去雄可解决此不育系繁殖问题。该雄性不育性利用方式优越,育种简便易行,能够满足对最佳组合选育的要求,且能够定向培育目标杂交组合。  相似文献   

禽致病性大肠杆菌luxS和rbsC双基因缺失株的构建及其生物特性分析     

涂春田  左佳坤  蒋蔚  陈兆国  米荣升  黄燕  韩先干  汪洋 《中国动物传染病学报》2021,(1):9-15

禽致病性大肠杆菌(APEC)能引起家禽严重的呼吸系统和全身性疾病,由于APEC耐药菌株的不断出现迫使新型抗菌方式的研发迫在眉睫.本研究旨在评价APEC的luxS和rbsC双缺失的突变株作为减毒疫苗候选株的潜力,通过在APEC分离株DE17的单基因缺失株DE17ΔluxS的基础上,利用Red重组系统构建双基因缺失株DE1...  相似文献   

重组酶聚合酶等温扩增技术在动物源性成分鉴定中的应用     

王伊琴  杨帆  郭文丽  陈少博  包勇敢  荆文魁  张志峰  常鸿  康晓平 《中国农学通报》2020,36(30):151-157

在打击肉制品掺假走私、维护市场秩序、保护野生动物资源等方面,对动物源性成分鉴定技术的特异性、灵敏性、重复性提出了很高的要求。本文阐述了动物源性成分的检测鉴定技术,有多样性和局限性的特点。归纳了重组酶聚合酶恒等温扩增技术原理与应用,解决了PCR技术在仪器上的局限性,优化了早期恒温扩增技术的缺点。指出重组酶聚合酶恒等温扩增技术为动物源性成分的快速准确鉴定提供了坚实的技术基础,并在动物疫病诊断方面也有很好的应用前景。  相似文献