Management of Meloidogyne incognita in yam-based cropping systems with cover crops

The effect of intercropping cover crops was with yam was assessed for nematode management both in pot and field conditions in Nigeria. The cover crops were sown with yams in pots containing sterile soil and inoculated with 5000 eggs of Meloidogyne incognita. In the field, each cover crop was separately intercropped with yams inoculated with 10,000 nematodes. From both pot and field experiments, no nematode damage was observed on yam tubers that were intercropped with Aeschynomene histrix, Crotolaria juncea, and Tagetes erecta. Damage in intercropped tubers was reduced by 72.7% with Mucuna pruriens, Centrosema pubescens, and Pueraria phaseoloides and by 58.3% with Stylosanthes guianensis compared to yams planted without cover crops; they also had lower (p ≤ 0.05) nematode populations. Cajanus cajan, Lablab purpureus and Vigna unguiculata however, supported high nematode populations and led to nematode damage in intercropped yams. Tubers from M. incognita-inoculated plants were more damaged and lost 42% more weight (p ≤ 0.05) following three months of storage than tubers from uninoculated plants. Intercropping yams with selected cover crops can be useful in managing M. incognita without reducing yam yields.     

宜昌市国有林场二次创业潜在优势的分析及出路探讨

作者就对宜昌市国有林场二次创业潜在的优势、出路及观念的改变进行了分析和探讨 ,为国有林场建设和发展不断注入新活力 ,实现林业跨越式发展奠定了基础     

小菜蛾抗性稳定性及抗性治理对策研究

试验表明，福州地区田间小菜蛾已对有机磷、氨基甲酸酯及拟除虫菊酯产 生高抗性。脱离选择压力3代后，小菜蛾的抗性水平迅速下降。Bt预处理可提高抗性和敏感小菜蛾幼虫 对有机磷的敏感性，尤其对抗性小菜蛾增效极显著，对敏感小菜蛾AChE的 Ki值则影响不 大。据此提出在抗性治理中，应轮用或换用不同毒理机制的杀虫剂，且其间隔至少为2～3代。     

青檀林伴生生物及主要有害生物种类初步研究简

2003～2013年,对山东枣庄青檀寺青檀林伴生生物和山东枣庄、泰安、济南,北京市妙峰山、上方山,山西灵丘县花塔,安徽青阳、泾县、全椒、滁州琅琊山等地青檀林主要有害生物种类进行调查研究。结果表明：枣庄地区青檀林伴生生物共有129种,其中病原微生物类8种,腹足纲动物1科2种,蛛形纲动物4科5种,昆虫纲动物7目、38科、55种,植物35科、59种。调查中发现的一种绵叶蚜经中国科学院动物研究所乔格侠研究员鉴定为绵叶蚜属一新种,定名为青檀绵叶蚜（Shivaphis pterocelti Qiao,Jiang and An,sp.nov.）。青檀林主要有害生物有腹足纲灰巴蜗牛[Bradybaena ravida （Benson）]和同型巴蜗牛[Bradybaena similaris （Ferussac）],蛛形纲山楂红蜘蛛（Tetranychus viennensis Zacher）,昆虫纲鳞翅目灯蛾科美国白蛾[Hlyphantria cunea （Drury）]、半翅目斑蚜科青檀绵叶蚜（新种）（Shivaphis pterocelti Qiao,Jiang and An,sp.nov.）、鞘翅目天牛科桑天牛[Apriona germari （Hope）]。同时,对青檀苗圃地杂草进行调查,共有17科37种。     

Microbial biomass and respiratory activity in soil aggregates of different sizes from three beechwood sites on a basalt hill

We studied the effects of aggregates of different sizes on the soil microbial biomass. The distribution of aggregate size classes (<2, 2–4, 4–10, >10 mm) in the upper mineral soil horizon (A_h layer) was very different in three sites (upper, intermediate, lower) in a beechwood (Fagus sylvatica) on a basalt hill (Germany). Aggregates of different sizes (<2, 2–4, 4–10 mm) contained different amounts of C and N but the C:N ratios were similar. C and N contents were generally higher in smaller aggregates. The maximum initial respiratory response by microorganisms in intact aggregates and in aggregates passed through a 1-mm sieve declined with the aggregate size, but the difference was more pronounced in intact aggregates. Disruption of aggregates generally increased this response, particularly in 4- to 10-mm aggregates in the lower site. Basal respiration differed strongly among sites, but was similar in each of the aggregate size classes. Aggregate size did not significantly affect the specific respiration (g O₂ g^–1 microbial C h^–1) nor the microbial: organic C ratio, but these parameters differed among sites. Microbial growth was increased strongly by passing the soil through a 1-mm sieve in each of the aggregate materials. The growth of microorganisms in disrupted aggregates was similar, and the effect of aggregate disruption depended on the growth of microorganisms in intact aggregates.     

蜡蚧轮枝菌防治植物病虫害研究进展

蜡蚧轮枝菌在蔬菜病虫害防治中有很大开发潜力。就蜡蚧轮枝菌的致病性、环境条件对其生长的影响、储藏期存活率及在生产中应用的概况的研究进展进行了综述。研究进展表明,该种真菌既可以防治粉虱、蚜虫、蓟马等蔬菜害虫,又可以防治蔬菜的白粉病、锈病等。     

人类活动对珠江三角洲酸性硫酸盐土壤发育的影响

In the Pearl River Delta with more than 1000 years of intensive land reclamation history,the development of acid sulphate soils has been generally limited in terms of their acid potential (pyrite content)and spatial extent.This is attributed to the rapid delta progradation,partially resulted from increasing sediment yield caused by deforestation within the catchment and the empolderment in the estuarine embayment.The empolderment practice accompanied by the clearance of mangroves stopped the upward growth of the pyritic layer on the one hand and limited the vertical accretion of non-pyritic freshwater sediments over the pyritic layer on the one hand and limited the vertical accretion of non-pyritic freshwater sediments over the pyritic estuarine sediments on the other.In such a case,the pyritic layer in the area is frequently thin and of shallow occurrence.Under forced leaching-recharge conditions for the paddy rice cultivation ,the leaching of acid sulphate materials prevails over its production and this leads to a net loss in pyrite oxidation products.Land excavation for fishpond farming accelerates pyrite oxidation due to the direct exposure of the pyrtic sediments to air on the pond bunds.Severe acidification can intensity the environmental degradation of estuarine ecosystems.     

进一步加强西藏自治区的小水电建设

在整理和分析西藏自治区40年小水电建设资料的基础上,着重总结了小水电建设和管理中存在的主要问题,并就今后如何搞好西藏的小水电建设提出了建议。     

窝铺山区森林植被水土保持效益及资源植物开发利用途径的研究

森林植被在涵养水源保持水土,减少土壤流失的作用很大,植物措施投资少,见效快、可长期发挥效益.对窝铺流域三年的治理及观测研究表明:森林植被保持水土效益明显;土壤侵蚀量小于其它植被类型;改善了生态环境;利于建立新的生态平衡,保证农业高产、优质稳定地发展.作者同时对研究区内的资源植物进行了调查分类,对资源植物的保护和开发利用提出了几个值得注意的问题.     

饲料加工企业内控评价指标体系的构建及其应用研究

面对日益复杂的竞争形势,饲料加工企业需要加强内控管理.为了评价内控体系的有效性,通常寻找一些评价指标形成体系对内控进行评价.本文提出构建内控评价指标体系需要一些前提,包括对关键环节的识别、评价原则的确定等,在指标选取中,至少应涵盖公司层面、业务层面、财务层面和合法合规层面的指标.内控评价体系构建后,需要有组织保障和制度...