ABSTRACT: To investigate the development and dynamics of green manure research, we collected 802 and 4588 papers on green manure research from China national knowledge infrastructure (CNKI) and Web of Science (WoS) between 1992 and 2021, respectively, and conducted quantitative and visual analyses based on bibliometric methods on the annual number of publications, authors and institutions, keywords, and emergent words. The main research hotspots in the field of green manure are discussed and summarized based on the results of the visualization analysis and the important publications explored by the results of the visualization analysis. The results showed that: the overall number of publications on green manure research exhibits an increasing trend, and research in this field is receiving more and more attention; the United States is the core country in this research field, with a great influence; although, the number of Chinese publications is large, the intermediary centrality value is small and the level of scientific research needs to be improved; the research characteristics in the field of green manure research mainly focus on green manure cultivation technology, the effects on soil and crops, and the effects on pests and diseases. The study was conducted based on CiteSpace, a visualization tool of bibliometrics, with comprehensive literature information and intuitive results, providing important references for relevant researchers to understand the extent of research in this field, academic communication, and grasp research dynamics.

RESUMO: Para investigar o desenvolvimento e a dinâmica da pesquisa de adubo verde, coletamos 802 e 4.588 artigos sobre pesquisa de adubo verde da infraestrutura nacional de conhecimento da China (CNKI) e da Web of Science (WoS) entre 1992 e 2021, respectivamente, e realizamos estudos quantitativos e visuais. Análises baseadas em métodos bibliométricos sobre o número anual de publicações, autores e instituições, palavras-chave e palavras emergentes. Os principais focos de pesquisa na área de adubação verde são discutidos e resumidos com base nos resultados da análise de visualização e nas importantes publicações exploradas pelos resultados da análise de visualização. Os resultados mostram que: o número total de publicações sobre a pesquisa de adubação verde apresenta uma tendência crescente, e as pesquisas nessa área estão recebendo cada vez mais atenção; os Estados Unidos são o país central neste campo de pesquisa, com grande influência, embora o número de publicações chinesas seja grande, o valor de centralidade intermediária seja pequeno e o nível de pesquisa científica precise ser melhorado; as características da pesquisa no campo da pesquisa de adubo verde concentram-se principalmente na tecnologia de cultivo de adubo verde, nos efeitos sobre o solo e as culturas e os efeitos sobre pragas e doenças. O estudo foi realizado com base no CiteSpace, ferramenta de visualização da bibliometria, com informações bibliográficas abrangentes e resultados intuitivos, fornecendo referências importantes para pesquisadores relevantes compreenderem a extensão da pesquisa neste campo, a comunicação acadêmica e a compreensão da dinâmica da pesquisa.

Abstract To explore a new method for the detection of soluble solids content (SSC) in apples, the reflectance spectra of apples with different SSC were obtained based on hyperspectral imaging technology in this paper, and fractal measurement of the reflection spectrum curve was carried out based on fractal theory, for using fractal dimension to quantitatively reflect its SSC. The results show that the samples with different SSC have little difference in fractal dimension, and are not sensitive to the change of apple SSC, which cannot show an obvious linear relationship. It can be considered to conduct a study on discrimination with obvious differences between spectral curves, such as variety discrimination and damage discrimination.

Abstract Grass cultivation in orchard technology has been implemented in some parts of the world, and different regions have different effects on fruits due to their different geographical environments. In this paper, Xinjiang, China, which has a temperate continental climate, is selected as the research area. Through orchard experiments and meta-analysis, the influence of grass cultivation on orchards in this area is studied. Experiments and the meta-analysis both showed that the single fruit weight, yield per plant and fruit quality were improved after grass cultivation in the orchards. This indicates that grass cultivation is of great significance to orchards in Xinjiang.

Abstract To explore the development process and trends of spectral technology in the fruit field, the quantitative and visual analysis of 849 documents from China National Knowledge Infrastructure (CNKI) and 4791 documents from Web of Science (WoS) in the fruit field was carried out in terms of the annual publication, authors and institutions, and keywords based on CiteSpace. According to the results of visual analysis and some important documents, the main research hotspots of spectral technology in the fruit field were discussed and summarized. The research based on the bibliometrics visualization tool CiteSpace expounds on the research of spectrum in the fruit field from a macroscopic and microscopic perspective. The document information is comprehensive and the results are intuitive, which can help researchers to understand the research progress, academic exchange, and grasp of the research in this field.

Abstract To find out the effects of hairy vetch cultivation on soil quality and productivity in Chinese orchards, all relevant papers in China National Knowledge Infrastructure (CNKI) published from 2000 to 2021 were collected to quantitatively analyze the effects of hairy vetch cultivation in orchards on soil physicochemical properties and nutrient content, soil enzyme activity, microbial activity, fruit yield and quality based on meta-analysis. The results showed that the effect sizes of hairy vetch cultivation on soil quality and productivity changed in a positive direction, but part of the effect sizes did not change significantly. This paper provides some support and reference for the development of grass cultivation in orchards.

Abstract This study proposes a novel method for jujube maturity and water content determination incorporating fractal theory. Firstly, the tissue section images of winter jujube at different maturity and tissue section image images of winter jujube with different moisture content were preprocessed by grayscale, median filter, histogram equalization and binarization. Secondly, the fractal dimension of jujube tissue section images of jujube at different maturity, and the fractal dimension of tissue slice images of jujube with different moisture content were calculated based on the box dimension algorithm. Finally, the relationships of the fractal dimension-maturity and fractal dimension-moisture content were explored. The results showed that the fractal features had good discrimination performance, the fractal dimension decreased with the increase of maturity, and the fractal dimension decreased with the increase of moisture content. This study provides a new way of thinking about the detection of physical and chemical indicators of winter jujube and other fruits. theory Firstly grayscale filter binarization Secondly algorithm Finally dimensionmaturity dimensionmoisture explored performance fruits

Abstract To understand the research status and current dynamics of fruit quality detection and objectively reflect the influence of different countries, research institutions and authors in this field, the software CiteSpace was used to bibliometrically and visually analyze the relevant literature on fruit quality detection in Web of Science (WoS) database from 1982 to 2021. The results showed that the number of publications on fruit quality detection showed a trend of slow in the early stage, rapid in the middle stage and intensified in the late stage. China has the largest number of international publications, accounting for 21.80% of the WoS database, but its intermediary centrality is inferior to that of the United States, Germany, Italy and Spain; the United States is at the core of international cooperation, establishing cooperative relations with most countries; through keywords co-occurrence network and keyword clustering, it is concluded that the research mainly focuses on fruit quality detection based on spectral technology or electronic nose technology, fruit composition detection based on high-performance liquid chromatography (HPLC), fruit edible safety detection, and genetic analysis of fruit quality-related traits. Bibliometrics and visual analysis of this fruit quality detection research can provide a certain reference for relevant researchers.

Abstract This paper explores the influence of the selection method of the region of interest (ROI) on the results in the total sugar of apple detection based on hyperspectral imaging technology. Taking Fuji apple as the detection object, the hyperspectral images of the samples were collected based on the 900~1750 nm hyperspectral imaging system, and the total sugar content of the samples was obtained based on the anthrone colorimetric method. The square ROI and circular ROI of different sizes were extracted. The average spectrum of the region was used to establish a quantitative analysis model of apple's total sugar content by partial least squares (PLS). The results show that apple's total sugar detection model established by extracting a circular ROI with a diameter of 25 pixels has the highest accuracy and strongest prediction ability(Rc = 0.8977, RMSEC = 0.6459, RP = 0.8836, RMSEP = 0.6627). The research shows that selecting ROI with a suitable shape and size for the research object is of great significance for improving the accuracy of the prediction model of apple's total sugar content and giving play to the advantages of hyperspectral images.