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1.
Fruit nutrient content and lipoxygenase (LOX) activity were determined in strawberry fruit to establish a relationship, if it exists, between nutrients, and LOX activity with the fruit malformation and nubbins or button berry disorders. Nearly 17% fruit were affected by malformation and 10% by nubbins in open-field-grown strawberries. ‘Etna’ produced higher proportion of malformed (22.7%) as well as button berries (16.9%) and ‘Sweet Charlie’ the lowest (8.9% and 3.3%, respectively). Dry matter content (%) was lower in malformed (5.2%) and button berries (3.23%) than normal berries (7.41%). The concentration of P and Mg did not differ significantly, but that of N and K was notably higher and of Ca and B was lower in malformed and button berries than normal berries. Consequently, the N/Ca and K/Ca ratios were higher in malformed and button berries. LOX activity was significantly higher in malformed as well as button berries than normal berries, with significant differences among cultivars. The correlations between N, K and malformed and button berries were positive and between Ca and B, and malformed and button berries were negative. Similarly, the correlation between LOX activity and malformed, and button berries were also positive, indicating that excess of N and K, and deficiency of Ca and B are related to the production of malformed and buttons or nubbins in strawberry. 相似文献
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Urban parks have been touted as spaces of diversity and democracy that have the potential to foster interracial contact among racially and ethnically diverse visitors. However, the extent to which they facilitate interracial contact and the factors related to contact are less understood. Using a quantitative panel study of racially and ethnically diverse U.S. urban residents (n = 931), this study investigated the influence of community diversity, motivations to visit parks, perceived engagement and representation, safety, and sense of welcome and belonging on interracial contact in urban parks. Results demonstrated more frequent and positive interracial contact when individuals perceived a greater sense of welcome and belonging and when they perceived more equitable engagement and representation. These results suggest that urban park agencies seeking to increase sense of welcome and belonging or frequency of positive interracial contact should focus on engagement and representation (as reflected through inclusive programs and events, input in decision making, and representation of racial and ethnic diversity) and safety. 相似文献
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摘要：有效利用有机资源、矿物资源和微生物资源，集成绿色农业新技术，可实现绿色、有机蔬 菜优质高产和产业可持续发展。对植物营养学理论、非豆科微生物固氮理论、植物次生代谢理论和有 益菌固碳减排理论等方面的研究进展进行综述，为绿色、有机蔬菜优质高产提供了理论依据；而研究 和应用高碳有机物、多功能微生物菌肥、天然矿物质营养及有机物耕层发酵技术，为绿色、有机蔬菜 优质高产提供了新机制。同时，提出了蔬菜优质高产“五要素”集成技术，以期为土壤连作障碍绿色 防控、绿色和有机蔬菜优质高产提供指导。 相似文献
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摘要：随着“一带一路”倡议的蓬勃发展,我国与沿线国家的农业合作不断深化,农产品贸易、农业技术合作、农业人才培养等前景广阔。白俄罗斯是“丝绸之路经济带”上的重要节点,也是最早参与和支持“一带一路”倡议的国家之一。为推动“一带一路”共建国家的农业合作,以中国与白俄罗斯的农业合作为例,从中国与白俄罗斯农业发展实际情况入手,分析了白俄罗斯农业发展中劳动力不足、种植结构不断调整、农产品进出口的现状,理清了我国与白俄罗斯在肥料贸易、农业创新技术合作等农业现代化方面的合作现状,并提出了在“一带一路”建设背景下,我国与白俄罗斯在农业科技、人才培养和农产品贸易方面的合作前景。 相似文献
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干燥是果蔬深加工中最常用的技术之一,可以提高果蔬制品的贮藏稳定性,减少损耗,增加果蔬附加值。我国果蔬干燥历史悠久,干燥技术种类繁多,从自然干燥到传统干燥到新型干燥再到联合干燥,不断发展。每种果蔬干燥技术都有其原理、设备、条件、特点及适用对象,人们可以根据加工需求选择最佳的干燥技术,以最短的时间、最低的成本生产高质量的产品。本文介绍了我国现有的果蔬干燥技术,比较了不同干燥技术的工作原理、优缺点以及适用对象等,并对果蔬干燥技术未来的发展方向进行了分析,以期为果蔬干燥技术的研究与应用提供参考。 相似文献
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J.C. Norman 《Scientia Horticulturae》1976,5(4):321-329
Definitions: Crown = the short stem and leaves growing from the apex of the fruit. Slip = leafy branch, attached below the fruit, developed from axillary bud on the peduncle. Happa = branch arising from axillary bud at the point of junction of peduncle and stem.Large-slip plants of ‘Sugarloaf’ pineapple (Ananas comosus) (L.) Merr.) were more vigorous than small-slip plants initially; however, plants from smaller slips caught up in size within a year after planting. Large-slip and medium-slip plants produced more slips and happas than small-slip plants. Smaller slips produced heavier and larger crowns, delayed both flowering and fruit maturity, reduced fruit size and yield, and recorded a higher incidence of sunburn. Slip size did not influence sucker development, peduncle size, and % TSS, % acidity and TSS/acidity ratio of the fruit.Deslipping, and decrowning and deslipping together produced significantly more suckers than control and decrowning-treatments. Deslipping-, and decrowning and deslipping together produced the maximum fruit weight and yield, whilst deslipping produced the longest fruits. Sunburn was greatest on decrowned and deslipped fruits, followed by deslipped fruits and then by control and decrowned fruits. Pruning did not influence happa production, peduncle size, fruit maturity, and % TSS, % acidity and TSS/acidity ratio of the fruit.No significant interaction between slip size and pruning was found. 相似文献
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Tardigrade communities are affected by micro and macro-environmental conditions but only micro-environmental variables, and
altitudinal gradients have been studied. We review previous reports of altitudinal effects and evaluate the influence by interacting
macro- (climate, soils, biome, and others) and micro-environmental (vegetation, moss and leaf litter) factors on tardigrade
assemblages at the Sierra de Guadarrama mountain range (Iberian Central System Mountains, Spain). Terrestrial tardigrade assemblages
were sampled using standard cores to collect leaf litter and mosses growing on rocks. General Linear Models were used to examine
relationships between Tardigrada species richness and abundance, and macro- and micro-environmental variables (altitude, habitat
characteristics, local habitat structure and dominant leaf litter type, and two bioclimatic classifications). Variation partitioning
techniques were used to separate the effects of altitude and habitat variation, and to quantify the independent influences
of climate and soil, vegetation structure and dominant type of leaf litter. Altitude shows a unimodal relationship with tardigrade
species richness, although its effect independent of habitat variation is negligible. The best predictors for species richness
were bioclimatic classifications. Separate and combined effects of macro-environmental gradients (soil and climate), vegetation
structure and leaf litter type are important determinants of richness. A model including both macro- and micro-environmental
variables explained nearly 60% of tardigrade species richness in micro-scale plots. Abundance was significantly related only
to soil composition and leaf litter type. Tardigrade abundance was not explained by macro-environmental gradients analysed
here, despite a significant correlation between abundance and richness. 相似文献
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摘要：为明确腐烂茎线虫能否侵染大蒜和被大蒜携带，选择腐烂茎线虫的马铃薯群体（P-Dd）和甘 薯群体（SP-Dd）作为接种源，于3—6月越冬后大蒜生长期开展田间试验。定期采样后，对大蒜根际土、 蒜根、茎盘、鳞茎进行分离和根内线虫染色检测。结果表明：腐烂茎线虫的马铃薯群体（P-Dd）和甘薯 群体（SP-Dd）均可对大蒜造成侵染。腐烂茎线虫可侵染大蒜的茎盘、蒜根和新生鳞茎。根际土中P-Dd和 SP-Dd群体的最大群体密度均出现在5月2日，每10 g土壤分别含107.0条和65.6条；蒜根中P-Dd和SP-Dd的 最大群体密度分别出现在3月14日和5月2日，每10 g根中分别含625.4条和1 303.3条；茎盘中P-Dd和SP-Dd 的最大群体密度分别出现在6月7日和6月15日，每10 g茎盘中分别含1 681.8条和2 983.3条；大蒜鳞茎只受 到轻微侵染，P-Dd和SP-Dd群体的最大群体密度均出现在5月30日，每10 g鳞茎中分别有2.7条和1.6条。 收获时，大蒜茎盘、鳞茎中均检测到腐烂茎线虫。尽管不同寄主来源的腐烂茎线虫对大蒜的侵染存在差 异，但可以确定的是其均能够侵染大蒜，并可随受侵染的鲜蒜进行传播。 相似文献
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园林绿化工程是一门实践性很强的学科,其中养护管理属长期、周期性工程,主要分析园林绿化养护管理的重要性及其特点,并针对北京地区各个季节的不同特点,介绍一些具体的养护管理方法。 相似文献
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无土栽培在黄瓜生产中应用广泛，而栽培基质是固定黄瓜根系，协调“水、肥、气”的基础物质，不同基质理化性质不同，可直接影响黄瓜的长势、产量及品质。研发筛选出适宜黄瓜生长的栽培基质是节能增效、促进生产的关键，从以椰糠、菌渣、农业废弃物堆肥为主的有机栽培基质，以蛭石、珍珠岩、河沙等为主的无机栽培基质，有机基质与无机基质混合的栽培基质，基质粒径大小、堆肥时间、栽培方式等性质和微生物制剂、腐植酸、生物炭、硅元素等外源添加物等方面综述了不同栽培基质对黄瓜生长、产量及品质影响的研究进展。基质栽培应用市场广阔，且将低成本可重复利用的农业作物废弃物作为有机基质并与无机基质混合配制成环保型复合基质成为无土栽培基质研究的主要方向。 相似文献
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微域环境温湿度与苹果果面碎裂的关系 总被引：2，自引：0，他引：2
为了查明果实微域环境温湿度与红富士苹果果面碎裂发生的关系,以10a生盆栽红富士苹果为试材,分别采取在果实发育期搭阴棚适当遮阴、高温时期喷水降温等处理措施进行研究。结果表明,遮阴+喷水处理的果面碎裂裂果率、裂纹指数均为最低,分别为44.47%、2.98mm/cm2,对照(常规管理)的裂果率、裂纹指数均为最高,分别为88.33%、8.03mm/cm2;不同时期、不同时间的温度与果面碎裂裂果率、裂纹指数均呈极显著正相关,相对湿度与果面碎裂裂果率、裂纹指数均呈极显著负相关;不同时期微域环境温湿度对果面碎裂的影响均以6月15-30日的相关系数最高。不同时间微域环境温湿度对果面碎裂的影响以12:00、14:00的相关系数较高。温度越高,相对湿度越低,果面碎裂现象越严重。 相似文献
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Urban and community forestry is an increasingly integral component enhancing the well-being of urban places. Along with providing aesthetic benefits and other critical ecosystem services, urban forestry contributes to local and regional economies by supporting jobs and economic activities through various businesses and industries. In this study, we estimated the economic contribution of urban forestry to the regional economy in terms of several economic and business metrics including jobs, labor income, value-added, and tax collections. To this end, we developed an extensive scope of urban forest industries and activities incorporating all private, public, and non-profit businesses and organizations involved in urban forestry in the Northeastern and Midwest states. Results from the input-output modeling suggest that in 2018, urban forestry in the Northeastern and Midwest states directly contributed $17.6 billion in industry output and $13.5 billion in value-added by supporting about 258,550 full- and part-time jobs in various businesses and activities. Including direct, indirect, and induced effects, urban forestry in the region had a total contribution of $34.7 billion in industry output to the regional economy, employing more than 357,200 people with a payroll of about $16 billion. These numbers are crucial to highlight the economic significance of urban forestry businesses and agencies as well as to educate the public, economic development professionals, and legislators about the importance of urban and community forestry in the Northeastern and Midwest states. 相似文献
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Idowu Babadele Famuwagun Samuel O Agele O.Peter Aiyelari 《International Journal of Fruit Science》2018,18(2):153-176
ABSTRACTThe deployment of plantain shade and irrigation (5- and 10-day) intervals) for enhancing survival, field establishment, flowering and pod production of field-grown cacao seedlings in the dry season was investigated. The effects of dry season irrigation was profound on cacao growth, field establishment (over 90% seedling survival) and development, flowering and pod production. For the non-irrigated moderately shaded cacao, about 30% of the transplanted seedlings survived and the achievable percent survival from the various shade-irrigation combinations ranged from 47–90%. Open sun in combination with 5-day irrigation interval had best results in term of growth (root and shoot development and biomass accumulation) and establishment, flowering and pod production. Lower values of air and soil temperatures were obtained for combination of irrigation and shade regimes (dense and moderate) and higher soil moisture contents. The shade-irrigation combinations ameliorated microclimate and enhanced growth and development, seedling survival, root and shoot development, advanced flowering and promoted uniform fruiting/pod production and total bean yield. The effects of dry season irrigation at 5- or 10-day intervals was profound on cacao growth, field establishment (over 90% seedling survival), flowering and pod production. Irrigated unshaded (open sun) cacao had best results in term of growth (root and shoot development and biomass accumulation) and establishment, flowering and pod production. The achievable percent survival from the various shade-irrigation combinations ranged from 47–90%. The drip irrigation strategy adopted ameliorated dry season terminal drought (hydrothermal stresses) and promoted cacao growth, survival and flower/pod production. 相似文献
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多胺引发处理对茄子种子活力及幼苗耐冷性的影响 总被引：4，自引：2，他引：2
以‘丰研2号’茄子种子为试材,分别用0.25mmol·L-1的亚精胺(Spd)和精胺(Spm)引发处理24h后,分别在10、15、25℃条件下进行种子发芽试验,并测定幼苗耐冷性等生理生化指标。结果显示,Spd和Spm处理可显著提高种子在低温胁迫条件下的活力,促进幼苗生长,显著降低了低温胁迫条件下幼苗细胞质膜透性和MDA含量,提高了抗氧化酶(SOD、POD、CAT)活性和脯氨酸、可溶性蛋白质的含量,表明多胺引发处理对提高低温胁迫下茄子种子活力及增强幼苗耐冷性具有重要作用。 相似文献