印楝素、鱼藤酮防治茶丽纹象甲成虫室内试验初报

通过室内试验研究了印楝素、鱼藤酮对茶丽纹象甲的杀虫效果。结果表明,药后2d,0.5%印楝素乳油1370倍液对茶丽纹象甲成虫的防治效果即达95.56%,药后3d达到100%,与2.5%联苯菊酯乳油1000倍液的差异不显著。0.5%印楝素乳油可作为有机茶园茶丽纹象甲防治的选择药剂。而7.5%鱼藤酮乳油750倍液,药后5d防效才达51.16%,防治效果较差。     

25％噻嗪酮对稻飞虱的防效评价

用25%噻嗪酮可湿性粉剂,10%吡虫啉可湿性粉剂,20%异丙威乳油(叶蝉散)在铜仁市对稻飞虱进行小区试验,结果表明,25%噻嗪酮可湿性粉剂和10%吡虫啉可湿性粉剂对稻飞虱均有良好的控制作用,20%异丙威最大剂量(40 g/667 m2)对稻飞虱的防效仅有80%的效果。     

印楝素、苦皮藤素防治茶卷叶蛾幼虫室内试验初报

开展了0.5%印楝素乳油、1%苦皮藤素乳油防治茶卷叶蛾室内药效试验。0.5%印楝素乳油800倍液和1%苦皮藤素乳油液750倍防治茶卷叶蛾效果良好,药后1、3、5 d防治效果分别为70.00%、85.19%、100%和66.67%、88.89%、95.83%,速效性也较好。初步试验结果表明,0.5%印楝素乳油、1%苦皮藤素乳油适用于茶园防治茶卷叶蛾幼虫。     

番木瓜疮痂病菌的室内药剂筛选

为了筛选出适合大田防治番木瓜疮痂病的药剂,采用菌丝生长速率法对8种药剂进行室内药效筛选。结果表明：8种药剂对菌丝生长的抑制效果不同,从方差分析结果来看,25% 咪鲜胺乳油、10% 苯醚甲环唑可湿粉填料、50% 多菌灵可湿性粉剂和25% 丙环唑乳油的EC50极显著或显著差异优于70% 甲基托布津可湿性粉剂、50% 异菌脲可湿性粉剂、80% 代森锰锌可湿性粉剂和50% 福美双可湿性粉剂;而25% 咪鲜胺乳油、10% 苯醚甲环唑可湿粉填料和50% 多菌灵可湿性粉剂间的EC50无显著差异,其中25% 咪鲜胺乳油的EC50最小。建议在生产上推广使用25% 咪鲜胺乳油、10% 苯醚甲环唑可湿粉填料和50% 多菌灵可湿性粉剂。     

花生疮痂病的药剂防治

采用70%甲基托布津可湿性粉剂、10%苯醚甲环唑可湿性粉剂、50%多菌灵可湿性粉剂、70%代森锰锌可湿性粉剂、30%爱苗乳油、75%百菌清可湿性粉剂、50%速克灵可湿性粉剂和苯醚甲环唑.多菌灵等8种药剂对花生疮痂病进行防治试验,结果表明：几种药剂均有一定的防治效果,其中70%甲基托布津可湿性粉剂和10%苯醚甲环唑可湿性粉剂的防治效果最好,单株结荚数多,果饱、果大,增产幅度最大;70%代森锰锌可湿性粉剂防治效果最差,增产幅度最小。     

阿克泰、天王星等药剂对茶假眼小绿叶蝉的药效试验报告

从几种药剂茶园小区防治茶假眼小绿叶蝉试验结果看,2.5%天王星乳油1000倍液、25%阿克泰水分散粒剂12500倍液、70%艾美乐水分散粒剂15000倍液、10%吡虫啉可湿性粉剂2500倍液、50%杀螟丹可溶性粉剂1000倍液和3%除尽悬浮剂1000倍液防治茶假眼小绿叶蝉防效良好,而0.5%苦参碱杀虫剂400倍液和3%除虫菊素水剂400倍液的防效虽不及以上化学农药好,但适用于茶叶绿色食品和有机茶园应用,若在常规茶园中应用最好与化学农药混用。为了避免抗药性的产生,以上药剂应轮换使用防治茶假眼小绿叶蝉。     

印楝素对水稻二化螟的生物活性及控制作用

 系统地研究了印楝素对水稻二化螟的生物活性及作用方式。试验结果表明，印楝素乳油对二化螟有胃毒、拒食、忌避、内吸等多种作用方式。0.75和0.50 mg/L印楝素乳油处理茭白饲喂3龄幼虫，幼虫分别于3、6 d内全部死亡；0.375、0.300和0.250 mg/L印楝素乳油低剂量处理茭白饲喂3龄幼虫，幼虫拒食率分别达94.38%、88.74%、80.07%；成虫产卵量分别下降80.70%、62.05%、40.86%。6、3和2 mg/L印楝素乳油处理初孵蚁螟，24 h内死亡率达100%。印楝素乳油对成虫产卵有显著的忌避作用。稻田喷施0.3%印楝素乳油62.5和125 mL/667 m2防治二化螟，21 d保苗效果分别为88.14%和94.13%，防治效果分别为85.36%和90.76%。表明印楝素对二化螟有较高的生物活性和理想的控制效果。     

0.3％印楝素乳油防治茶小绿叶蝉试验

印楝素~([1])被公认为开发最为成功的具有现代意义的植物源农药~([2]),是最适用于作物整体管理和有害生物综合治理的一项植保措施。为了探索该药剂在茶树上对茶小绿叶蝉~([3])的防治效果,本研究采用0.3%印楝素乳油250倍液和4%阿维菌素乳油1500倍液为供试药剂并单独施用进行了初步试验,实验结果表明:0.3%印楝素乳油药剂比4%阿维菌素乳油药剂防治茶小绿叶蝉更理想,且药后7天左右防治效果最好,此时防效在50%以上,减退率在60%.作用持效时间相对较长,可维持在14d以上,且对茶树生长安全、对天敌亦无影响。     

爱禾0.3%印楝素防治小绿叶蝉和茶黄蓟马的药效试验

小绿叶蝉是我国茶树上一类最为常见且为害严重的害虫,一般为害损失达20%左右,最严重者无茶可收.茶黄蓟马是茶树上的潜伏性害虫,在雨水少湿度小的季节发生严重.爱禾0.3%印楝素乳油是云南中科生物产业有限公司生产的植物源农药,为明确它对小绿叶蝉、茶黄蓟马的防治效果、使用浓度,以及对茶叶产量和品质有无影响,云南省农科院茶叶研究所于2003年3～4月进行了爱禾0.3%印楝素乳油防治小绿叶蝉和茶黄蓟马的室内和田间药效试验,并进行了施用后对茶叶产量和品质的影响试验.     

几种低毒农药防治甜菜夜蛾药效试验

田间试验结果表明，10％赛虫特可湿性粉剂450g／hm^2和15％及杀乳油450g／hm^2对甜菜夜蛾防治效果较好，防效分别为74．6％-98．1％和51．0％-91．2％，显著高于4．5％高效氯氰菊酯可湿性粉剂450g／hm^2，防效37．0％，49．6％，4％吡高乳油225g／hm^2，防效19．8％24．4％，16000IU／μL苏云金杆茵悬浮剂750g／hm^2，防效0．16%-66．6％．     

Analysis of nutritional components of eight famine foods of the Republic of Niger

In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply.     

芦笋枯萎病病原鉴定

对造成福建省漳州市东山县的芦笋枯萎病病原菌进行分子鉴定,以期确定病原菌的属、种名,为防治该病害寻求理论依据。试验对分离纯化的病原菌核糖体DNA的ITS区进行测序,在Genbank中搜索其同源性并构建它们的系统发育树,结果表明：引起芦笋枯萎病的病原菌是镰刀属中的尖孢镰刀菌(Fusarium oxysporum),且病原菌之间的同源性高达89%,遗传差异不显著。     

狗牙根诱变后代抗寒性评价

通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT₅₀)的变异范围为-7.6～-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。     

Mechanism of action of insecticidal secondary metabolites of plant origin

Insect pest management is facing the economic and ecological challenge worldwide due to the human and environmental hazards caused by majority of the synthetic pesticide chemicals. Identification of novel effective insecticidal compounds is essential to combat increasing resistance rates. Botanicals containing active insecticidal phytochemicals appear to be promising to address some of these problems. Therefore, there is a continuous need to explore new active molecules with different mechanisms of action. Secondary metabolites present in plants apparently function as defense (toxic), which inhibits reproduction and other processes. The phytochemical biomolecules could be used for maximizing the effectiveness and specificity in future insecticide design with specific or multiple target sites, while ensuring the economic and ecological sustainability. In this article, the current state of knowledge on phytochemical sources and insecticidal activity, their mechanism of action in insects, resistance, and promising advances made in phytochemical research are reviewed.     

玉米产量性状配合力遗传分析

通过对8个中晚熟玉米自交系产量性状进行双列杂交分析，表明各个自交系产量性状的一般配合力与特殊配合力存在显著差异，玉米杂交种F₁的产量构成受到一般配合力与特殊配合力的共同作用，用特殊配合力对F₁的作用大于一般配合力。特殊配合力高低与一般配合力无明显相关关系。因此在玉米杂交种组配与自交系改良工作中，既要兼顾双亲的一般配合力与特殊配合力，又要保持杂交优势利用模式与选系模式的种质关系。     

橡胶树丛枝病病原的抗血清制备与应用

以感染橡胶树丛枝病病原的长春花为材料,制备得到橡胶丛枝病病原菌抽提液,以抽提液为抗原免疫家兔,制备抗血清,经微量沉淀测定,抗血清效价为１：２０４８。应用橡胶丛枝病抗血清检测橡胶褐皮病,无症苗木检出率达３０％－３７％,可疑的褐皮病树检出率达８５．７％。     

几个粳稻不育系、恢复系产量性状配合力研究

新粳型不育系和恢复系是通过籼粳交或粳粳交的方式培育而成的中间型稳定品系,杂交组合的育性正常或接近正常。粳型不育系和恢复系配组,杂种F1的产量性状差异显著或极显著。组合9512A/R364、73A/R55、150A/R198、9512A/R2690、150A/R55,具有产量的正向超亲、超标优势,另一些组合呈显著或极显著的负向优势;本研究产量性状一般配合力好的不育系是中14A、辽150A、73A、9512A、9214A,恢复系是R198-2、R238、R46、C418、R364和花38;亲本的产量性状一般配合力和特殊配合力在不同性状的作用没有交叉。杂种优势的表现与双亲亲和力高低、配合力高低有明显的相关性。辽150A、9512A的超亲优势明显,R198、R55、R2690、R364、C204等恢复系具有较强的杂交优势。不育系对产量性状的作用显著大于恢复系。     

Size and frequency of occurrence of pre-roost gatherings of starlings

One hundred and fifty-six pre-roost gatherings of starlings were observed at 28 sites around a roost in west Norfolk during winter. Pre-roost gatherings occurred more frequently at individual farmyards compared with individual fields, but 82% of the sites where gatherings occurred were on fields. The size of gatherings was greater, the closer to the roost. Birds in pre-roost gatherings on fields of autumn-sown winter wheat spent most of the time feeding and had a diet composed almost exclusively of wheat seeds. Birds in gatherings on grass fields also fed intensively whereas only 31% of birds at farmyards were feeding. The implications that these results have with regard to potential damage to fields of winter wheat and around farmyards are discussed.     

马铃薯黑痣病菌生物学特性测定

马铃薯黑痣病是土传真菌性病害,在定西市马铃薯种植区均有发生,目前已成为影响马铃薯产量和品质的主要因素之一。本研究对马铃薯黑痣病菌从温度、光照、碳源、氮源以及p H方面进行了生物学特性的测定。结果表明:该病原菌菌丝在无光25℃条件下生长最快,在无光35℃条件下生长最慢;室温条件下培养1 d后用紫外线照射处理2 h,然后室温持续光照培养4 d的菌丝生长速率最大,持续黑暗培养4 d的菌丝生长速率最慢;不同碳氮源对该菌菌丝生长均有影响,碳源为淀粉的培养基上菌丝生长最快、氮源为尿素的培养基上菌丝生长最快;培养基p H中性时菌丝生长速率最大。     

中耕方式对土壤理化特性及玉米生长发育影响研究Ⅰ.中耕方式对玉米生长发育的影响

2002～2003年在0～3次中耕条件下研究了中耕方式对玉米生长发育和产量形成的影响。结果表明,多次中耕增大了玉米倒伏率,降低了玉米最大叶面积指数、株高及各时期叶片叶绿素含量,对花粒期玉米净光合速率、气孔导度、蒸腾速率也产生一定的负面影响。少中耕有增产的趋势,并且可以降低生产成本、增加经济效益。