水稻细菌性条斑病的发生与防治

水稻细菌性条斑病（Ｘａｎｔｈｏｍｏｎａｓｏｒｙｚｉｃｏｌａ）简称细条病,为国内植物检疫对象,近年来在我国部分稻区严重发生,一般减产１０％左右,重病田高达５０％～６０％。一、为害特点：水稻细菌性条斑病主要侵害叶片,病斑初呈暗绿色水渍状半透明小斑点,后逐...     

小麦赤霉病在阳谷县暴发流行

小麦赤霉病１９９８年在我县严重发生。５月下旬调查,全县５万ｈｍ２小麦病田率１００％,病穗率２０％～４０％,高的达７０％以上。有的全穗发病、有的半穗或１／３穗发病。病穗部分籽粒干秕、皱缩,有的发黄,同时颖枯、叶枯病伴随危害,减产２０％～３０％。过去小麦...     

小麦赤霉病防治新法

小麦赤霉病是合川市一种发生普遍 ,危害严重的小麦病害。据调查 ,在中度流行年份 ,病穗率３０%～５０% ,减产５%～２０% ;大流行年份 ,病穗率可达５０% ,减产２０%～４０%。赤霉病不仅使小麦减产 ,而且有毒性 ,会严重降低小麦品质。人食病麦后 ,四肢无力、头昏、腹胀、腹泻、呕吐。牲畜吃了 ,食欲减退、腹泻 ,严重的会中毒死亡。小麦赤霉病是一种全生育期病害 ,能引起种、苗、秆、穗的腐败。穗腐危害性最大 ,其次是秆腐 ,苗腐只在个别情况下发生。病穗呈枯黄色 ,在病部出现一层粉红色胶状物 ,叶片、叶鞘呈灰白色。病穗子粒干秕、皱缩、丧失…     

水稻细菌性褐条病的发生与防治

水稻细菌性褐条病近年来在湄潭县流行危害越来越重。根据该站及各镇（乡）农技站调查统计 ,全县平均每年流行面积５５０ｈｍ２～６００ｈｍ２,严重年份达１０００ｈｍ２,发病田块的病株率１５%～３０ % ,严重田块达１００ % ,造成水稻减产绝收 ,严重影响全县粮食生产。一、发病症状水稻细菌性褐条病在苗期至穗期均可危害。但在湄潭县 ,发病主要在秧田期至抽穗前 ,５～７月为主要发病时间 ,水稻抽穗后很少发病。秧田期发病 ,叶片和叶鞘初期呈现水渍状长条 ,沿中脉上下发展 ,病斑逐渐变为黄褐色至黑褐色 ;但在田间只是零星出现病株。大田期发…     

小麦梭条花叶病的发生情况调查及流行因素分析

小麦梭条花叶病１９９１年在天长市零星发生，以后为害逐年加重，目前已成为本市春季小麦的主要病害之一。发病田块一般减产１０％～２０％，严重的高达６０％，少数达毁耕程度。为探明该病害在本市的发生为害情况，我们对该病的症状、发生规律及流行因素作了进一步探讨。１症状观察外部症状：感病小麦在三至五叶期后，从新生心叶上出现褪绿条纹，继而发展成为与叶脉平行的条斑，或呈梭条状，梭条斑中心可引起坏死，叶片逐步黄化以至枯死。少数品种心叶严重褪绿时细弱扭曲，有时亦出现葱管状症状。病株根系发育差，新根少，褐色根多。拔节后…     

新疆阿勒泰地区哈密瓜细菌性叶斑病发生严重

新疆阿勒泰地区从 1999年开始试种哈密瓜。但连续 2 a所种约 700 hm2瓜，在多年从未种过瓜的田块里从苗期开始就发生细菌性叶斑病，病株率 100％，病叶率高达 95％，后期病叶成片枯焦，病蔓、病瓜腐烂，减产 50％～ 80％，给瓜农造成极大的损失，也限制了哈密瓜种植业的发展。 1症状 　　该病在瓜的整个生育期均可发生。幼苗子叶受害，初在边缘出现水渍状斑，后不断扩展，使子叶干枯或局部干枯，严重的造成死苗。成株期受害叶片上初呈不规则淡黄色斑点，后渐渐变成水渍状、不规则形病斑，早、晚天气凉爽时从病斑处渗出灰白色菌脓，中午气温…     

水稻细菌性条斑病的综合防治

水稻细菌性条斑病Xanthomonas campestris pv.oryzicola是国家规定的植物检疫对象。该病发生以后,一般病田可减产10％～20％,重病田可达4～6成。近年来,该病在我国南部稻区呈传播蔓延趋势,已危及水稻生产的安全。尤其在杂交水稻制繁种基地,一旦发现该病,则直接影响水稻种子的使用,其后果更为严重。实践表明,水稻细菌性条斑病可随带病种     

小麦蜜穗病及其为害状

小麦蜜穗病及其为害状小麦蜜穗病为我国较少见的一种细菌性病害，是小麦线虫病的一种并发病。封面照片右为穗部放大，有黄色胶状菌脓，左为线虫为害引起的叶片扭曲。孙广宇（西北农业大学植保系陕西杨陵７１２１００）小麦蜜穗病及其为害状@孙广宇$西北农业大学植保系...     

小麦叶枯病在阳谷县大流行

今年小麦叶枯病在山东省阳谷县大流行,病株率100%,病叶率高达95%。病株严重叶枯,影响灌浆,造成减产1—2成。成为生产上的重要问题。小麦叶枯病主要危害叶片和叶鞘。小麦自第一真叶至旗叶都可发病。在叶片上生成分散的病斑或造成大片斑块,使叶片由叶尖向下枯萎死亡,抽穗以前下层叶片发病较多,病斑呈圆形或梭形,淡绿色或黄白色并渐扩大成不规则淡褐色斑块,散生黑色小颗粒,严重时全叶黄褐枯死。小麦叶枯病病菌(Septoria tritici Rob.etDesm.)。当秋季病菌侵入麦苗后,以菌丝体     

山东阳谷小麦根病的发生与防治

近年小麦根病在我县日趋严重。据调查全县病株率约４０％～６０％左右,高的达９０％以上。每年产量损失１０％～３０％。我县小麦根病主要是指纹枯病、根腐病和全蚀病。这几种病害发生在茎基部和根部,植株花杆、烂茎、形成白穗,造成减产。阳谷县根病严重的主要原因是：１．土壤菌源丰富：小麦、玉米等作物收获后,根茬多留在土壤中,致使菌量逐年增多。另外,农民习惯于用根茬、麦糠沤制土粪,其上的病菌潜存于土粪中带入土壤。又因我县是小麦———玉米一年两熟制,连作田杂草多、寄主广泛,土壤中病菌量大面广。如遇适宜环境条件,即可…     

Roles of flavoproteins in degradation of mexacarbate in rats

The nature of a reductive system which actively degrades mexacarbate in the rat intestine and liver was investigated. The system is characterized by its stability against heat and protease treatments and its requirements for a flavin cofactor and an acidic pH for a maximum activity. As a result of purification and spectroscopic identification attempts the system responsible for the above reductive activity was identified to be flavoprotein. Under anerobic conditions such flavoproteinflavin cofactor systems degrade mexacarbate first to 4-N-desmethylmexacarbate and then to polar water-soluble metabolites.     

祁连山老虎沟地区高寒草甸蒸散发估算

利用祁连山老虎沟地区海拔4200m气象观测站2010年的观测资料,采用FAO Penman-Monteith公式,再利用作物系数法,对高寒草甸生长季(5月22-9月22)的蒸散发量进行估算和分析。结果发现:研究期共有124天,蒸散发总量为238.3mm,日均为1.87mm·d-1。生长初期、生长中期、生长末期的蒸散发总量依次为22.6mm,179.1mm,36.6mm,依次占研究期总量的8.4%,75.2%,15.3%。5月下旬至6月中旬,日均蒸散发量以较低水平缓慢上升;6月下旬迅速增加;6月末至7月中旬猛然回落;7月中旬至8月末,日均蒸散发量迅速上升且维持在较高水平;此后直到9月22日,缓慢减少。5-9月月蒸散发总量依次为6.6mm,46.4mm,74.5mm,77.6mm,33.1mm。     

Aetiology of Rhizoctonia in sheath blight of maize in Sichuan

Rhizoctonia isolates obtained from maize grown in commercial fields in 33 representative counties (or cities) in Sichuan province in China were characterized according to colony morphology, hyphal anastomosis and pathogenicity. Of 141 isolates, 116 were identified as R. solani , 23 as R. zeae and two as binucleate Rhizoctonia . The isolates of R. solani were assigned to four anastomosis groups (AG): AG-1-IA (101 isolates, accounting for 71.6% of the total), AG-1-IB (2, 1.4%), AG-4 (9, 6.4%) and AG-5 (4, 2.8%). The two isolates of binucleate Rhizoctonia belonged to AG-K. On maize, isolates of AG-1-IA caused typical sheath blight symptoms. Lesions produced by isolates of AG-4, AG-5, AG-1-IB and AG-K were darker than those of AG-1-IA. Rhizoctonia zeae usually caused discontinuous lesions with a dark brown margin and a brown centre on the leaf sheaths, as well as ear rot. Isolates of AG-1-IA were the most virulent to maize, with an average lesion length of approximately 15 cm. Isolates of R. zeae produced lesions approximately 12 cm long, while those of AG-4, AG-5, AG-1-IB and AG-K were progressively shorter. On potato dextrose agar (PDA; pH 6.4), the minimum temperature for mycelial growth of R. zeae isolates was 14–18°C, the maximum 38–40°C and optimum 30°C. Isolates of R. zeae did not grow on PDA (28°C) at pH 2.0, the optimum for growth being pH 6.4.     

西北地区冬季室内三种常绿植物的光合特性比较

使用Li-6400XT便携式气体交换系统的红蓝光源和液化CO_2钢瓶注入系统,模拟冬季室内较密闭环境下存在较高CO_2浓度且为弱光环境,设置CO_2浓度为600μmol·mol~(-1),并以400μmol·mol~(-1)作为对照组(CK),对绿萝(Scindapsus aureus)、鹅掌柴(Scheffera octophlla(Lour).Harins)和燕子掌(Crassula agenten Thunb.)进行光响应(Pn-PAR)曲线的测定。结果显示:在CO_2浓度600μmol·mol~(-1)下,三种植物的光饱和点(LSP)均比(CK)更早出现,绿萝和鹅掌柴总体的净光合速率(Pn)比(CK)高,燕子掌比(CK)低;绿萝的最大光合速率(Pmax)、光饱和点(LSP)和表观量子效率(YAQ)均最高,分别为5.62±0.145μmol·m~(-2)·s~(-1)、373.51±24.15μmol·m~(-2)·s~(-1)和0.041±0.003μmol·μmol~(-1),但暗呼吸速率(Rd)较低(-0.51±0.14μmol·m~(-2)·s~(-1));鹅掌柴和绿萝的水分利用率(WUE)和蒸腾速率(Tr),极显著高于燕子掌(P<0.01);绿萝的叶绿素SPAD值最高(70.03±4.18),极显著高于其余两种(P<0.01)。研究表明,绿萝对光照具有最强的利用能力,且能在高CO_2浓度且干旱的环境里健康生长,并能对室内环境起到较强的增湿效应,是西北地区冬季较为理想的室内植物。     

山西省2012年蔬菜农药残留监测结果分析

本文通过对2012年山西省蔬菜农药残留监测结果的分析,找出造成山西蔬菜农药残留问题原因,并针对性的提出了解决问题的对策,为蔬菜生产提供依据。     

环流特征量指数在新疆汛期降水趋势预测中的应用

利用中国气象局气候中心下发的74类环流特征量值,通过相关分析,建立了新疆10个区域的汛期降水预测模型。结果表明:预测模型对新疆汛期降水趋势有一定的预报能力,尤其是在新疆洪涝灾害多发的伊犁及博尔塔拉蒙古自治州、北疆沿天山一带、天山山区,建立的3个区域预测模型可以作为汛期降水预测的主要工具。     

Incidence of benomyl and iprodione resistance in isolates of Botrytis cinerea in tomato crops in England and Wales in 1986

In 1986, mass-mycelial isolates of Botrytis cinerea from 67 tomato crops in England and Wales were examined for benomyl and iprodione resistance. Of the 706 isolates obtained, 62.7% were resistant to benomyl at 2μg/ml and 43.2% were resistant to iprodione at 2 μg/ml. Iprodione resistance persisted in the absence of a dicarboximide spray programme. The incidence of benomyl resistance has not decreased since the last survey in 1984 in spite of a considerable reduction in the use of benzimidazole fungicides. There were no clear indications that the use of dichlofluanid influenced the incidence of benomyl or iprodione resistance. Disease control was poorer in crops with a higher incidence of iprodione resistance.     

Viruses of pepper in plastic houses in Crete

During a survey of virus diseases affecting pepper grown in plastic houses in Crete, during 1984–1986, tomato mosaic virus (ToMV) and tobacco mosaic virus (TMV) were detected. The most common virus was TMV, being present in samples of alle pepper cultivars carrying the L₁ resistance gene, while ToMV was isolated only from susceptible pepper cultivars. According to responses ofCapsicum spp. the isolates from 640 samples checked were classified into three pathotypes: P₀, P_1.2 and P_1.2.3. Results of this study show that P_1.2 represents at present the major threat to the Cretan pepper industry.Samenvatting Bij een in de jaren 1984–1986 gehouden inventarisatie van virusziekten in paprika in plastic-foliekassen op Kreta werd zowel het tabaksmozaïekvirus (TMV) als het tomatemozaïekvirus (ToMV) aangetoond. TMV kwam zeer algemeen voor: het werd aangetroffen in alle monsters van de paprikarassen met het resistentiegen L₁. ToMV werd alleen geïsoleerd uit planten van vatbare paprikarassen. Volgens de waargenomen symptomen die de isolaten van 640 monsters opCapsicum spp. vertoonden, konden de isolaten in drie pathotypen, nl. P₁, P_1,2 en P_1,2,3, worden geklassificeerd. Uit het onderzoek is gebleken dat P_1,2 de belangrijkste bedreiging vormt voor de teelt van paprika op Kreta.     

Viruses of tomato in plastic houses in Crete

Tomatoes grown in plastic houses in Crete have been inspected since 1980 for virus diseases. Plants with virus-like symptoms were checked by sap inoculation to test plants and the isolated viruses were identified by host reaction and serology. The most common viruses were, in order of frequency, tomato mosaic virus (ToMV), potato virus X, tomato bushy stunt virus (TBSV), potato virus Y and cucumber mosaic virus. The large use of ToMV-resistant cultivars reduces gradually the importance of ToMV while TBSV tends to become a serious problem of tomato in Crete.Samenvatting Van 1980–1984 werden op Kreta de in plasticfolie-kassen geteelde tomaten geïnventariseerd op de aanwezigheid van virussen. Verdachte plante werden door sapinoculatie op toetsplanten onderzocht. De daarbij geïsoleerde virussen werden daarna via de symptomen op de waardplanten en serologisch geïdentificeerd. In volgorde van belangrijkheid werden de volgende virussen het meest aangetroffen: tomatemozaïekvirus, aardappelvirus X, tomatedwerggroeivirus, aardappel Y virus en komkommermozaïekvirus, De laatste jaren is door de toenemende teelt van tomaterassen met resistentie tegen tomatemozaïekvirus het belang van dit virus sterk verminderd, terwijl het tomatedwerggroeivirus een steeds ernstiger probleem lijkt te worden.     

2013年我国黏虫发生特点分析

2013年黏虫维持了2012年以来的重发态势。二代黏虫在东北、华北、黄淮局部、江南局部、西南地区普遍发生,多种作物受害严重,总体发生程度重于2012年同期,山西、河北等局部地区大发生。三代黏虫在东北、华北和黄淮局部等地偏重发生,虽然发生面积、发生程度整体上不如2012年严重,但是仍显著重于常年,并且在辽宁、山西、山东的局部地区造成严重危害。分析提出,监测防控及时到位、关键时期气象条件不利,是2013年三代黏虫发生程度轻于2012年的主要原因。