旱(直)播水管稻田杂草化学防除配套技术研究

水稻的直播是一项省工、省本、省力、经济效益高的栽培技术。但直播稻田的草害严重地阻碍了直播稻的发展。直播稻田因草害一般减产30％左右,严重的田块减产50％以上,甚至颗粒无收。为了解决直播稻生产中的草害问题,我们在省农科院植保所稻田草害组的主持下,从1985年开始进行了旱播水管直播稻田杂草化学防除体系的研究。现将三年中所取得的主要结果报告如下: 试验方法 (一)旱播水管直播稻田杂草发生消长规律调查旱播水管直播稻田播种后定6点,每点1平方尺。在整个生育期内,每3天调查1次,     

免耕旱直播稻田扫茀特除草试验初报

免耕旱直播稻田杂草严重,影响直播稻高产,利用化学药剂除草,是解决直播稻田杂草的重要手段。1988年我站采用30％扫茀特进行除草试验,现初报如下: 一、材料与方法试验在白蒲镇文峰村三组进行,前茬小麦,轻壤土,肥力中等,地势平坦。供试品种为盐粳3号中稻。田间主要杂草有水苋菜、千金子、莎草属杂草等,一般每平方米有杂草150株左右。     

旱直播稻田化除效果的影响因素

该文介绍了旱直播稻田杂草发生特点,回顾了通州市旱直播稻田杂草化除技术现状,分析了旱直播稻田化除效果的影响因素与存在问题,提出了控制对策。     

丙草苄防除旱直播稻田杂草的应用技术

由于直播稻田干干湿湿 ,封行期推迟 ,对杂草的发生极有利 ,因而旱直播稻田杂草具有发生种类多、发生期长、数量大、危害严重等特点 ,若不及时进行化除 ,往往会形成草荒 ,对水稻高产丰收构成极大威胁。因此 ,寻求对旱直播稻田杂草防除效果好 ,对水稻秧苗安全可靠的除草剂是旱直播稻田杂草化除上亟需解决的难题。为了进一步明确丙草苄防除旱直播稻田杂草的化除效果、应用技术及对水稻的安全性 ,２０００年在通州市进行了丙草苄防除直播稻田杂草试验 ,取得了理想的结果。现将试验结果整理如下 :一、材料与方法１．供试药剂及水稻品种。１６%丙…     

旱直播稻抑草潜力的评价

利用旱直播稻自身的竞争及化感作用,评价旱直播稻品种（品系）对杂草的抑制作用。采用田间小区试验方法,评价旱直播稻对杂草的竞争能力和耐受能力。通过测定旱直播稻特征化感次生物质含量计算出的化感指数来评价其化感潜力;在旱直播稻播种后45 d,杂草生物量与旱直播稻的生物量成显著负相关、与相对竞争强度成显著的正相关。旱稻品系‘HF04’和‘HF011’对杂草的抑制作用最强,前者抑草能力强表现在竞争力,后者抑草能力强表现在耐受杂草竞争力和化感作用。     

机械水直播稻田杂草及其综合治理

水直播稻田杂草发生严重,是制约水直播稻高产的关键因子之一。本文研究了水直播稻田杂草的发生与危害规律,提出了防治水直播稻田杂草的关键在于防止杂草出土,建立以化学防治为主,协调各种农艺除草措施为基础的水直播稻田杂草综合治理体系。     

杂草稻生长性状观察

杂草稻又称杂草型稻,是一种恶性杂草.近几年来在如皋市发生蔓延迅速,尤其在直播稻田杂草稻已上升为优势草种,严重影响水稻的产量.2008年笔者等在水稻分蘖末期进行普查,直播稻田杂草稻发生田块达50%.每平方米有杂草稻0～18.8株.平均2.35株,杂草稻分蘖一般为30个左右.抛秧栽培稻田发生田块为23.7%.每平方米有杂草稻0～6.87株,平均0.76株,分蘖一般为20个左右,少于直播稻田.     

上海地区杂草稻发生分布与危害现状

2009年对上海10个区县79个乡镇共3 140.8 hm2直播稻田和857.5 hm2机插秧稻田进行了杂草稻发生分布与危害现状调查。结果表明,直播稻田杂草稻发生频率为22.15%,面积发生率为14.72%,乡镇分布率为75%;机插秧稻田杂草稻发生频率为22.71%,面积发生率为22.66%,乡镇分布率为77.27%。上海地区直播稻田和机插秧稻田杂草稻均以1级轻度危害为主。直播稻田杂草稻3级以上危害面积占发生面积的比率、发生频率和乡镇分布率均高于机插秧稻田。     

异丙·丁·苄WP防除水稻直播田杂草的效果及应用技术

50％异丙·丁·苄（速除）WP（异丙隆、苄嘧磺隆和丁草胺复配）是江苏省苏科农化有限责任公司研制生产的用于水旱直播稻田的除草剂。能有效防除稻田多种一年生禾本科杂草、阔叶类杂草和莎草科杂草,包括千金子、稗草、鳢肠、陌上菜、异型莎草等。直播稻田的杂草防除效果是影响直播稻产量的关键。     

杂草稻与栽培稻叶片生长的竞争性研究

杂草稻造成栽培稻产量的损失主要表现为叶片间的相互竞争。争夺空间、争夺光照矛盾突出。杂草稻主茎叶片多于栽培稻,最大叶片长于栽培稻,最大叶片宽于栽培稻,叶片披散,形似杂交稻叶。如果在667 m2旱直播稻田接种2.5 kg粳性杂草稻籽,栽培稻上部全被杂草稻稻叶覆盖,栽培稻植株瘦黄、弱小,茎、蘖逐步退化消亡,造成基本绝产。     

福寿螺配偶个体大小选择性初步观察

通过野外观察与实验研究,掌握了福寿螺的婚配体制及其配偶选择性规律。福寿螺与多数低等动物一样,其婚配属于乱交制,无固定配偶;雌螺对与其交配的雄螺个体大小没有选择性,而雄螺对雌螺的个体大小有选择性,倾向于与较大个的雌螺交配。     

厚朴病虫害种类的初步调查

采用标准地法和线路调查法,对湖北恩施市新塘乡双河厚朴基地的厚朴病虫害进行了系统调查,记录主要虫害13种,其中叶部害虫9种,枝干害虫2种,根部害虫2种。厚朴主要病害5种。藤壶蚧、厚朴枝角叶蜂和厚朴新丽斑蚜为湖北省首次报道,小绿叶蝉为厚朴新寄主记录种。同时记录了藤壶蚧的天敌6种,其中寄生小蜂2种,瓢虫4种;厚朴新丽斑蚜的天敌昆虫8种。对藤壶蚧、厚朴枝角叶蜂和厚朴苗木根腐病等重要病虫害的发生规律进行了初步调查,同时提出了防治建议。     

Localization of metabolic sites of action of herbicides

Time- and concentration-course studies were conducted to determine the effect of thirteen herbicides on photosynthesis, respiration, RNA synthesis, protein synthesis, and lipid synthesis using isolated single leaf cells. Each herbicide was from a different chemical class. Appropriate ¹⁴C-substrates and product purification procedures were used for each process prior to liquid scintillation counting. The most sensitive metabolic site of inhibition was photosynthesis for atrazine, bromacil, dichlobenil, monuron, and paraquat; RNA synthesis for dalapon and dinoseb; protein synthesis for chlorpropham; and lipid synthesis for CDAA, chloramben, 2,4-D, EPTC, and trifluralin. However, with several herbicides, one or more process was almost as sensitive as the one mentioned above. All herbicides inhibited more than one process, and the most sensitive site of inhibition may not be the same process that was inhibited the greatest at the maximum concentration and maximum exposure time used. Therefore, a concept of metabolic sites of action, rather than a primary site of action, appears to be more meaningful for herbicides.     

百合地下害虫主要种类调查及生物（源）农药筛选

调查了甘肃省临洮县为害百合的地下害虫种类, 并以主要发生为害种类为供试对象, 采用拌土法测定了几种生物（源）农药对主要害虫的室内毒力和致死中时。调查发现小云斑鳃金龟Polyphylla gracilicornis、棕色鳃金龟Holotrichia titanis为主要发生及为害种类, 不同时间发生种类存在差异, 9月份以小云斑鳃金龟幼虫发生为害为主, 发生量占地下害虫总数的66.16%, 平均种群密度为10.48头/m2, 10月份, 则以棕色鳃金龟幼虫发生为主, 发生量占地下害虫总数的96.86%, 平均种群密度为7.79头/m2, 主要取食百合根系和鳞茎, 造成根系数量减少, 鳞茎出现不规则褐色缺口或凹陷斑。药剂筛选结果表明, 1.8%阿维菌素乳油、200亿孢子/g球孢白僵菌粉剂对两种蛴螬均具有较高的杀虫活性和速效性, 药后7 d时, 校正死亡率在82.22%以上, 对小云斑鳃金龟幼虫和棕色鳃金龟幼虫的LC50分别为0.161、0.060 mg/g和5.558×107、0.362×107孢子/g, LT50分别为2.237 d（2.2 mg/g）、1.393 d（2.2 mg/g）和6.645 d（40.0×107孢子/g）、4.940 d（2.0×107孢子/g）, 这两种生物（源）农药对两种蛴螬的LC50和LT50值均略大于两种化学农药25%二嗪磷乳油、40%辛硫磷乳油处理的, 且对小云斑鳃金龟幼虫的杀虫活性均低于对棕色鳃金龟幼虫的杀虫活性, 致死中时则长于对棕色鳃金龟幼虫的致死中时。     

Effects of timing and method of application of Penicillium oxalicum on efficacy and duration of control of Fusarium wilt of tomato

The effects of timing and method of application of Penicillium oxalicum on the control of fusarium wilt of tomato were investigated. Application of P. oxalicum to tomato seedlings in seedbeds reduced disease caused by Fusarium oxysporum f.sp. lycopersici in a growth chamber by 45–49% and in glasshouse experiments by 22–69%. Disease suppression was maintained for 60–100 days after inoculation with the pathogen in the glasshouse. No disease reduction was observed in tomato plants where P. oxalicum was applied to seeds. Treatment with P. oxalicum did not affect the population of F. oxysporum f.sp. lycopersici in the rhizosphere.     

Systems of designation of pathotypes of plant pathogens12

A variety of systems of designation has evolved to name pathotypes of plant pathogens. The systems were evaluated to determine those best suited for particular purposes. Virulence and avirulence/virulence formulae of pathotypes have advantage over the use of consecutive numbers or letters given in chronological order of pathotype discovery. As soon as pathotype information exceeds a certain level of complexity, mathematical codes are most advantageous, in particular two codes, octal notation and coded triplets. A more universal adoption of the most appropriate codes is recommended to ease communication and comparisons of results.     

Investigation of the Mode of Action of Nematode Neuropeptides

The neuropeptide AF2 has a complex set of actions on the dorsal muscle strip of Ascaris suum, including a potentiation of the acetylcholine-stimulated muscle contraction. Caffeine at 100 μm and 5 mm inhibited this potentiation, as did 100 μm theophylline in two out of six studies. The cyclic-AMP-potentiating compounds IBMX, dibutyryl cAMP and forskolin had no effect on the AF2-induced potentiation of the acetylcholine-stimulated muscle contraction. These preliminary data suggest that the potentiating action of AF2 is not mediated by a cAMP pathway.     

Mode of action of meturine

The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues.     

Mode of action of etoxazole

The mode of action of the 2,4-diphenyl-1,3-oxazoline acaricide/insecticide etoxazole has been argued to be moulting inhibition, but experimental results supporting this hypothesis are lacking. This study investigated the effect of etoxazole on chitin biosynthesis in the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). Etoxazole induced moulting defects in fall armyworm larvae similar, if not identical, to those caused by benzoylphenylureas, a well-known class of insecticidal chitin biosynthesis inhibitors. Furthermore, in contrast to untreated larvae, the chitin content in the integuments of larvae several days after treatment did not differ from that in freshly ecdysed individuals, thus suggesting strong chitin biosynthesis inhibition in vivo. A more detailed investigation of the inhibitory potential by incubating cultured integument pieces from larvae of S. frugiperda with [14C]N-acetyl-D-glucosamine, a radiolabelled chitin precursor, revealed I50 values of 2.95 and 0.071 microM for etoxazole and triflumuron respectively. The incorporation of radiolabel into potassium hydroxide-resistant material was inhibited by etoxazole in a dose-dependent manner. Based on these results, it is concluded that the acaricidal and insecticidal mode of action of etoxazole is chitin biosynthesis inhibition.