天竺葵病害及其防治

概述天竺葵主要病害的病原物、症状及其防治措施,并列出77种天竺葵病害种类名录。     

Enhancement of revegetation on construction fill by fertilizer and topsoil application: Effect on mycorrhizal infection

The influence of topsoil and fertilizer application on denuded road construction sites was evaluated to assess its contribution to improvement of vegetation re-establishment. the study sites were within a mixed hardwood and conifer forest on crushed, unweathered subsurface material with low fertility and low biological activity. Topsoils were removed from the site, stockpiled and reapplied to the site after construction. the effect of topsoil amendment on plant growth, soil fertility, mycorrhizal infection and an index of microbial biomass were measured in field and greenhouse experiments. Plant growth on the topsoil amended field plots were greatly increased relative to treatments with fertilizer but no topsoil. Three years after establishment, dry weight production on the plots without topsoil treatment was about 40 per cent of the plots treated with topsoil. Greenhouse experiments were designed to compare fresh, dried and stockpiled topsoil. These experiments indicated that storage of the harvested topsoil for five months in a stockpile had minor effects on plant growth, soil fertility, mycorrhizal infection and microbial biomass. Topsoil volumes had to exceed 20 per cent of the total soil volume to achieve statistically significant benefits and higher ratios showed greater benefit. the percentage of mycorrhizal infection was greatest in topsoil treatments without fertilizer. the addition of fertilizer increased growth but reduced the percentage of roots forming mycorrhizae. When the total weight of infected roots was calculated, however, infection was found to be greatest with a moderate level of fertilizer (equivalent to approximately 27 kg N ha⁻¹ and 39 kg P ha⁻¹), and was less in both higher fertilizer treatments and in unfertilized treatments. Topsoil amendment increased microbial biomass nitrogen but fertilizer treatment did not.     

芒果采后主要真菌性病害及防治方法研究进展

芒果是热带、亚热带重要经济作物之一,因其独特的口感和丰富的营养价值深受消费者喜爱。由于芒果采收期正值高温多雨季节、果实采后生理代谢旺盛、采收难度大,采后运输、贮藏过程中易遭受真菌的侵染,成为限制芒果产业发展的重要因素。为防治芒果采后真菌性病害,国内外学者对芒果采后防治技术进行了研究与开发。对炭疽病、蒂腐病和曲霉病3种芒果采后主要真菌性病害的症状、危害、病原菌和发生条件进行了综述,总结了芒果采后真菌性病害的防治方法,并对芒果采后病害防治方法进行了展望,为芒果采后真菌性病害防治技术的发展提供理论基础。     

生防木霉菌Tr9701的鉴定及其生物学特性

对从土壤中分离、筛选出的生防木霉菌进行分类鉴定和生物学特性测定。结果表明,生防木霉菌属于半知菌类、丛梗孢目、木霉菌属,为绿色木霉(Trichoderma viride)。该菌以小麦粉和豆粉浸出液培养基生长最适,在小麦粉和PDA培养基上孢子生成最快、产生孢子量多,分生孢子在1%葡萄糖溶液中萌发效果最好;20~30℃为其菌落生长和分生孢子形成的适宜温度;木霉菌菌落生长和孢子可以耐受45℃的高温,致死温度为55℃持续15 min;适宜pH为5~8;短时间紫外线照射不会对生防木霉菌的生长和孢子着生产生影响。     

基于PLC的蟹笼渔船诱饵填盒与塞笼自动化流水线方案设计

蟹笼渔船诱捕饵料在使用过程需要经过破冰分离、切块、填盒、塞笼等工序,效率低、劳动强度大.为提升蟹笼渔船的生产效率,需要实现饵料使用自动化.提出了一种实现饵料使用自动化的流水线生产方案,并通过Pro/ENGINEER Wildfire 5.0进行流水线的结构设计建模与原理分析,采用GX works3基于三菱FX5U系列P...     

无锡茶园不同修剪模式对茶小绿叶蝉发生量的影响

为优化春茶后茶园修剪模式,提高小绿叶蝉控制率,对福鼎大毫和福鼎大白进行不同修剪时间和不同修剪高度的比较,综合结果显示,福鼎大毫以4月28日修剪高度45 cm,小绿叶蝉总控制率最高;福鼎大白以5月25日修剪高度45 cm,小绿叶蝉总控制率达到最高.     

发动机电磁气门驱动技术的研究进展

电磁气门驱动是一种新型的可变配气相位技术.通过对电磁气门驱动技术的研究进展分析,指出了电磁气门驱动走向实用化应解决气门软着陆、高响应速度及电磁气门驱动装置足够小等技术难题.     

CJD交流电力测功机的研制

介绍了自行研制的CJD交流电力测功机的结构、工作原理以及系统控制的实现过程.运行结果表明,该CJD交流电力测功机具有结构简单,稳定性、可靠性好,使用方便,适用性广等特点,节能效果显著,能量反馈效率最高可达到74%.     

Assessing Repeated Oxalic Acid Vaporization in Honey Bee (Hymenoptera: Apidae) Colonies for Control of the Ectoparasitic Mite Varroa destructor

The American beekeeping industry continually experiences colony mortality with annual losses as high as 43%. A leading cause of this is the exotic, ectoparasitic mite, Varroa destructor Anderson & Trueman (Mesostigmata: Varroidae). Integrated Pest Management (IPM) options are used to keep mite populations from reaching lethal levels, however, due to resistance and/or the lack of suitable treatment options, novel controls for reducing mites are warranted. Oxalic acid for controlling V. destructor has become a popular treatment regimen among commercial and backyard beekeepers. Applying vaporized oxalic acid inside a honey bee hive is a legal application method in the U.S., and results in the death of exposed mites. However, if mites are in the reproductive stage and therefore under the protective wax capping, oxalic acid is ineffective. One popular method of applying oxalic is vaporizing multiple times over several weeks to try and circumvent the problem of mites hiding in brood cells. By comparing against control colonies, we tested oxalic acid vaporization in colonies treated with seven applications separated by 5 d (35 d total). We tested in apiaries in Georgia and Alabama during 2019 and 2020, totaling 99 colonies. We found that adult honey bees Linnaeus (Hymenoptera: Apidae), and developing brood experienced no adverse impacts from the oxalic vaporization regime. However, we did not find evidence that frequent periodic application of oxalic during brood-rearing periods is capable of bringing V. destructor populations below treatment thresholds.