松阳县古松树的松材线虫病现状调查与分析

古松树是历史的见证,是文化的承载,其保护工作具有重要意义,但因松材线虫的传播侵染,其生存状况不容乐观。本研究以松阳古松树为对象,基于分子检测技术,对其松材线虫病现状进行了调查与分析。结果表明,有12个乡镇近60%的古松树均已感病,疫情较为严重,需及时开展抗病保护工作。     

加强农业建设项目监管的对策建议∗ ——以中国热带农业科学院为例

文章介绍了农业科研院所基本建设项目管理的现状，并指出农业建设项目监管中存在管理制度建设不完善、建设项目实施管理不规范、管理队伍专业化程度不高等问题。该文指出建设单位要通过完善农业建设管理制度、强化农业建设项目的实施管理、提升管理队伍能力建设等举措，加强农业基本建设项目监管，全面强化在建项目法律风险防控。     

良好农业规范（GAP）发展现状与建议——以云南省为例

良好农业规范在保证农产品质量与安全和出口中发挥着重要作用。综述了国内外良好农业规范认证发展情况及特征，结合2006-2017年间中国良好农业规范（CHINAGAP）在云南省的认证规模、区域分布和主体构成等指标，探讨了其在云南省的变化趋势。CHINAGAP在云南省呈现快速增长趋势，认证形成了以种植业为主、畜牧和渔业为辅的行业格局。但云南省认证总量偏少，认证可持续性和认知度较低等问题也制约了CHINAGAP在云南省的进一步发展。结合国内外良好农业规范发展经验，提出了加强政府引导，出台奖励办法；发挥企业与专业合作社示范作用，提高GAP认证积极性；加大CHINAGAP标准的宣传和推广力度等建议，为推动CHINAGAP认证工作在云南省的持续发展提供理论依据。     

达州市经济作物产业发展现状与对策

通过分析达州市经济作物产业发展现状和存在的问题,提出了促进当地经济作物产业发展的对策建议,为推动地区特色经济作物产业高质量发展提供参考。     

生态养猪技术要点及未来发展趋势

猪肉作为主要的食物来源之一,传统的自然养殖已不能填补人们对品质的要求。有机养猪作为此类食品的主要新型品种之一,最重要的特点是生态性、绿色性和安全性。该文主要分析生态养猪技术的要点及其未来发展形势。     

基于文献计量学的山茱萸研究现状分析

山茱萸具有降血糖、抗氧化、抗肿瘤、抗菌等功能作用,开发山茱萸资源具有重要意义,其研究受到广大科技工作者的关注。为了解近10年来山茱萸的研究现状,本文采用文献计量学方法,以中国学术期刊网络出版总库(CNKI)2009—2018年的数据为检索对象,从年度分布、研究机构、学科分类、期刊来源等方面分析山茱萸研究文献,以期为研究者提供参考。     

我国玉米病虫害发生现状、趋势与防控对策

近年来,随着我国农业种植结构的调整和耕作栽培方式的转变,玉米品种选育加快,种植面积迅速增加,玉米病虫害发生一直呈加重趋势,一些次要病虫害在全国范围或局部地区为害不断加重,上升为主要病虫害,生产上还出现了一些新发病虫害,对玉米安全生产构成了威胁。本文总结了我国玉米重要病虫害的发生现状,并对发生趋势进行了分析,目前生产上的重要病虫害如亚洲玉米螟、桃蛀螟、棉铃虫以及黏虫为害加重并将持续发生;土传病害玉米茎腐病、穗腐病等危害将持续加重;风险性叶斑病玉米大斑病、南方锈病等仍在流行,未来不可忽视;还需关注未来危害性具有上升趋势的病虫害。提出了相应的防控对策。     

Water circulation induced by mechanical aerators in a rectangular vessel for shrimp aquaculture

A water streamer was designed for the purpose of enhancing cost-efficient circulation between the water surface and bottom of shrimp aquaculture ponds. We took direct measurements of the water current field induced by the designed aerator in a large rectangular reservoir of dimensions (L)50 × (W)19 × (D)1.3 m³ and compared the results with those of a standard Taiwanese paddle-wheel aerator. Vertical circulation between the surface and the bottom induced by the paddle wheel aerator was less than that by the designed aerator. Furthermore, the paddle-wheel aerator consumed more electric power than the designed aerator. The structures of water current induced by the two aerators are elucidated, and the advantages and disadvantages of the aerators are discussed.Auxiliary employment of the designed aerators may contribute to delivery of high DO water throughout the pond, which is more efficient than a paddle wheel aerator.     

Dual effects of reversed winter–spring temperatures on year‐to‐year variation in the recruitment of chub mackerel (Scomber japonicus)

To clarify the effects of temperature on the recruitment of chub mackerel (Scomber japonicus) in the North Pacific, we investigated the influence of winter surface temperature (WST) on spawners at the time of maturity around the spawning grounds and the influence of ambient spring temperature on larvae using estimated temperature (ET) obtained from particle tracking experiments. We found a significant positive correlation between ET approximately 10 days following hatching and the recruitment per spawning stock biomass (RPS) after 2000. The closer (more meandering) the Kuroshio Current (KC) axis was in relation to the spawning ground, the higher (lower) the spring surface temperature and the higher (lower) RPS was in the spawning ground. In contrast, WST inside KC near the maturity/spawning ground was significantly negatively correlated with RPS. A significant negative correlation between the temperatures in winter and spring was detected in the area after 2000, when the conditions of the Pacific decadal oscillation index and the stability of the Kuroshio Extension were synchronous, indicating that KC shifted northward during this time. The reversed temperature pattern was consistent with the winter–spring movement of KC axis in the offshore direction and was correlated with the winter–spring difference in the intensity of the Aleutian low. These results suggest that the annual variation in chub mackerel recruitment after 2000 was strongly affected by the combined effects of ambient temperature because of the reversal of conditions that occurred between winter and spring around the maturity/spawning ground, which was related to the KC path.     

湖南省森林公园在全省旅游经济中的地位评析

通过分析近10年间湖南省森林公园旅游收入在全省旅游经济中的地位变化情况 ,发现全省森林公园旅游收入增长势头强劲但不太稳定 ,总体呈波状运行态势 ,在全省旅游经济中所占比重较小但潜力巨大 ,提出了应优化产业结构、推动产业链延伸、健全森林旅游产品体系 ,为全省旅游产业发展培育新的经济增长极.