稻田养鱼是水稻病虫草害综合防治的好途径

我国稻田养鱼有悠久的历史,我省青田县在六百多年前就已经有稻田养鱼的记载。长期以来,我省稻田养鱼主要分布在浙南瓯江两岸的山区,是一项传统的农艺技术。近些年来,我省稻田养鱼有了较大的发展,特别是进入八十年代以后,养鱼稻田面积迅速增加,至1984年全省已达到27.19万亩,1985年又增加到36.5万亩。稻田养鱼不仅可以充分利用稻田水面,增     

稻田综合利用与病虫防治

随着产业结构的调整、土地利用率的提高,稻田综合利用已走入千家万户,我县进行了稻田养鱼和稻田放养板鸭的稻田综合利用开发,并取得了显著的经济效果。全县稻田养鱼面积到1991年已达5100亩,一般亩产成鱼25—30公斤,高的达50公斤,1992年计划发展到6万亩。全县稻田放养板鸭,今年要     

江苏省阜宁县2008年不同播栽类型稻田杂草发生情况与防除技术

2008年7月份对江苏省阜宁县不同播栽类型稻田杂草发生情况进行了调查.不同播栽类型稻田杂草的发生情况不同,旱育移栽和机插秧稻田杂草种群简单,直播稻田杂草发生种群复杂,草相、草量明显多于旱育移栽和机插秧稻田.     

生态稻田及常规稻田节肢动物群落结构特征的比较研究

用吸虫器、黄板诱捕、黄盆诱捕和扫网4种采样法,对双季稻区生态稻田及常规稻田两类生境稻田中的节肢动物群落结构特征进行了比较研究。结果表明：早稻和晚稻整个生育期,生态稻田中节肢动物天敌的物种数显著高于常规稻田。稻田生境多样性有利于促进稻田节肢动物天敌群落的建立,生境越复杂,植被多样性越高,物种种类就越多。     

稻田施药对稻田蜘蛛的影响研究

稻田喷施杀虫剂会大量杀伤稻田蜘蛛,反复施药导致稻田蜘蛛长期处于低密度状态。影响稻田蜘蛛发生有药剂种类、剂型、施药部位、用量、喷药次数、施药器械与喷径等因素。     

制种稻田杂草的发生与化学除草剂对父母本水稻的影响

杂交制种稻田的产量取决于父、母本花期相遇程度。多年来,由于惧怕化学除草剂会影响父母本花期相遇,所以化学除草技术没有在杂交制种稻田推广应用。为了能有效地控制杂交制种稻田的草害,降低劳动强度,进一步提高杂交制种稻田的经济效益,1989年我们对杂交制种稻田杂草的发生消长,以及目前所推广的化学除草剂对父母本生育进程的影响进行了试验研究。一、材料与方法 (一)杂交制种稻田杂草发生消长调查在麦后制种稻田父本移栽后,分设母本小苗移栽、母本水直播和全栽父本(常规稻对照     

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。     

赣北地区稻田杂草调查

为了摸清稻田杂草的种类及其分布,笔者于1984～1987年和2007～2008年对赣北地区稻田田间杂草进行了抽样调查。1稻田杂草种类根据调查结果,赣北稻田共查得杂草21个科48种。     

稻田养鱼灭蚊与农村经济发展的研究

自1983年起,我们连续五年开展稻田养鱼灭蚊的研究。1987年WHO/TDR赞助了这项 科题,我们不仅从稻田养鱼灭蚊作用出发,同时转向考虑农民的利益,更注意于农业和经济的效益。 设现场在广西全州县,该县的可养鱼稻田占稻田总面积的70％以上,特别是居民区的稻田养鱼甚为普遍。对近10年来稻田养鱼与内源性疟疾发生及与广西全区疟疾年发病率的关系作了回顾性调查。另在南宁市近郊设置实验田,研究稻田养鱼对水稻的生长发育和土壤的理化性质的影响,以及对水稻和鱼产量的效应。     

养蟹养鱼稻田病虫草防治技术

充分利用稻田资源优势 ,大力发展稻田养蟹、养鱼 ,是当前稻区农村产业结构调整的一项热门工程。它利用稻田动植物间互补性 ,稻田空间给鱼蟹提供了活动场所 ,而鱼蟹觅食田间杂草和水稻无效分蘖及部分害虫 ,减轻了虫草为害 ,综合效益明显。养蟹稻田 ,667ｍ2 产稻谷 4 0 0ｋｇ以上 ,蟹 4 5ｋｇ以上 ;鱼蟹混养田 ,667ｍ2 产稻谷 4 0 0ｋｇ以上 ,蟹 3 0ｋｇ以上 ,鱼 55ｋｇ以上。 667ｍ2 纯增效益 1 2 0 0元以上。但稻田病虫草防治技术性较强 ,稍有不慎 ,鱼蟹覆灭。通过几年摸索 ,现将养蟹养鱼稻田的植保技术整理如下 :1　鱼蟹稻田的适合药种与用…     

3-[2-(4-氯-苯基)-1-(3,3-二甲基-氧代-丁基)-乙烯基]-2-氰基亚胺-1,3-噻唑的合成研究

本文研究了3-[2-(4-氯-苯基)-1-(3,3-二甲基-氧代-丁基)-乙烯基]-2-氰基亚胺-1,3-噻唑的合成方法,对反应的各个步骤中的投料摩尔比、溶剂、温度和催化剂进行了对比,优化了反应步骤,总结出了产率较高的合成路径。设计合成了未见报道的新型噻唑衍生物类化合物。其结构经红外光谱、氢核磁共振和气质联用谱图确认,总收率为37.3%。该合成技术降低了成本,减轻了对环境的污染,具有很好的发展前景和市场竞争力。     

A stereoselective versatile synthesis of 3-(2,2- dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acids

A straightforward high-yield synthesis of cis-3-(2,2-dihalovinyl)-2,2-dimethylcyclo-propanecarboxylic acids is described which uses only inexpensive starting materials and reagents. The synthesis of these acids, involving a [2+2]-cyclo-addition of halogenated ketenes with 2-methylpropene and two rearrangements (the ?cine’? and the Favorskii rearrangements) as the key steps, exemplifies the conceptually new synthesis.     

The synthesis of 3-(2,2-Dichlorovinyl)-1- methylcyclopropane-1,2-dicarboxylic acid

3-(2,2-Dichlorovinyl)-1-methylcyclopropane-1,2-dicarboxylic acid, a metabolite of the pyrethroid insecticide permethrin, has been synthesised as a mixture of isomers, in four stages, in high overall yield.     

Stereochemical and chiral aspects in the synthesis of 3-(2,2- dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acids

The synthesis of (1RS)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid by dehydrohalogenation of 4,6,6,6-tetrahalohexanoates has been modified to produce stereo-selectively the cis-isomer. A new stereospecific synthesis of cis-3-(2,2-dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acids using a bicyclic lactone and its extension to the preparation of the optically active (1R)-cis acid are described.     

普通小麦-华山新麦草易位系H9020-1-6-8-3抗条锈病基因的遗传分析和SSR标记

 It have proved that wheat translocation line H9020-1-6-8-3 derived from Psathyrostachys huashanica Keng is an important resistant resource to stripe rust.To confirm the existence of resistant genes,it was crossed with susceptible cultivar MingXian 169 as male and female parent,respectively.Seedlings of parents and F₂ progeny were tested for resistance to selected CY29 of races of Puccinia striiformis f.sp.tritici from China.H9020-1-6-8-3 had one dominant resistant gene which temporarily named YrHs,whatever it was male or female parent.By using BSA method,two markers,Xgwm261 and Xgwm455 located on 2DL were found.The distance to YrHs were 4.3 and 5.8 cM respectively.The result could be used in molecular-assisted breeding.     

Photochemical behaviour of dichlorprop [(+/-)-2-(2,4-dichlorophenoxy)propanoic acid] in aqueous solution

Aqueous solutions of dichlorprop were irradiated under different conditions of pH, wavelength and oxygenation. The photochemical behaviour was found to be complex and many photoproducts were formed. However, at low concentrations the main photoproducts were 4-chloropyrocatechol, 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol. Some other photoproducts were identified, namely 2-(4-chloro-2-hydroxyphenoxy)propanoic acid, 2-(3,5-dichloro-2-hydroxyphenyl)propanoic acid and 2,4-dichlorophenyl acetate. From comparison with results previously obtained with mecoprop [2-(4-chloro-2-methylphenoxy)propanoic acid] it appears that the presence of a chlorine atom in position 2 on the ring strongly modifies the photochemical behaviour.     

2-氰基-3-[(6-氯)-3-吡啶甲基]氨基-3-脂肪氨基丙烯酸乙酯的合成

以3-氨甲基吡啶和2-氯-5-氨甲基吡啶为原料先与2-氰基-3,3-二甲硫基丙烯酸乙酯反应得到中间体2a和2b,不经分离,直接与脂肪胺反应,合成了7个未见文献报道的开环类吡虫啉结构化合物3.所有目标化合物(包括2a和2b)均经元素分析和1H NMR确证,并对其构型进行了讨论.     

2-氰基-3- 氨基-3-脂肪氨基丙烯酸乙酯的合成

以3-氨甲基吡啶和2-氯-5-氨甲基吡啶为原料先与2-氰基-3,3-二甲硫基丙烯酸乙酯反应得到中间体 2a和2b, 不经分离,直接与脂肪胺反应,合成了7个未见文献报道的开环类吡虫啉结构化合物 3 。所有目标化合物(包括 2a和2b )均经元素分析和1H NMR确证,并对其构型进行了讨论。     

2-(1,5-亚戊基)-5-取代亚氨基-Δ3-1,3,4-噻二唑啉的合成及杀菌活性

为考察脂肪环的大小对噻二唑啉衍生物杀菌活性的影响,以环己酮为原料,先与取代缩氨基硫脲缩合,得N-取代环己酮缩氨基硫脲,再经二氧化锰氧化关环,得到9个未见文献报道的标题化合物,所有化合物的结构均经过IR、13C NMR和元素分析确证。初步杀菌实验结果表明,所有目标化合物在100 mg/L和50 mg/L浓度下,对棉花立枯病菌Rhizoctonia solani Kühn和棉花枯萎病菌Veticillium dahlide具有一定的杀菌活性,特别是对棉花立枯病菌,在50 mg/L下有5个化合物的抑制率达90％以上。     

Effects of ametryn [2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine] on nitrate reductase activity and nitrite content of wheat (Triticum aestivum L.)

The objectives of this study were to show that: (a) a herbicide, such as ametryn, which interferes with the photosynthetic electron transport system, causes nitrite to accumulate in illuminated leaves and (b) that nitrite is toxic and contributes to the herbicidal damage and death of the plant. Tests were conducted on wheat seedlings grown on 5 mM nitrate, 5 mM ammonia, and zero nitrogen. Ametryn treatment decreased in vivo and in vitro nitrate reductase activity (NRA) within a 26-hr period. In vivo NRA decreased more rapidly than in vitro NRA. Compared with control tissue, only 3% in vivo NRA remained at the end of 26 hr. The in vivo assay conducted in light confirmed the inhibition of photosynthetic electron flow by ametryn within the leaf tissue. Nitrate-grown, ametryn-treated plants accumulated nitrite and, after 10 days were the only plants that were completely desiccated and dead. Ammonia- and zero-nitrogen, ametryn-treated plants did not accumulate nitrite, were only partially chlorotic after the 10-day period, and were still living. Low levels of NO_(X) (NO₂ and/or NO) emissions were demonstrated by nitrate-grown ametryn-treated plants.