Tea Harvesting Research Articles

Occurrence and Risk of Metal(loid)s in Thelesperma megapotamicum Tea Plant.

This study reports on the harvesting, ingestion, and contamination of American Indian tea Thelesperma megapotamicum grown on the Navajo Reservation in New Mexico. Uranium (U) and co-metal(loid)s (As, Cd, Cs, Mo, Pb, Se, Th, and V) have contaminated local soil and plants. Tea plants were gathered for analysis near U mining impacted areas. The study collected samples of wild tea plants (n = 14), roots (n = 14), and soil (n = 12) that were analyzed with inductively coupled plasma mass spectrometry. Tea harvesting activities, behavior, and ingestion information were collected via questionnaires. Harvesting took place in community fields and near roadways. Results indicate edible foliage concentration levels for Cd exceeded the World Health Organization (WHO) raw medicinal plant permissible level guidelines. Tea samples collected near high traffic areas had significantly greater Cd and Mo concentrations than those collected near low traffic areas (p < 0.001). Tea sample metal(loid) concentration levels ranged from 0.019–7.916 mg/kg. When compared to established food guidelines including the WHO provisional tolerable weekly intake (PTWI), reference dietary intake, recommended dietary allowance, and the tolerable upper limit (UL), Cd exceeded the WHO guidelines but none exceeded the PTWI nor the UL. These findings warrant improved standardization and establishment of universal guidelines for metal(loid) intake in food.

Structural analysis on cutting notch of tea stalk by X-ray micro-computed tomography

Quantitative analysis on cutting notch of tea stalk is one method to better understand shear resistance and mechanical properties of the stalk, which could improve cutting performance and efficiency for tea harvesting. Optimal design of the cutter might be achieved through structural analysis of cutting notch by X-ray micro-computed tomography (micro-CT). The third inter-node of the stalks were sampled and scanned by micro-CT after they were cut at different cutting depths (0.7, 1.5, 2.3 mm) and cutting edge angles of cutter (30°, 35°, 40°). The structural change of the cutting notch and cutting force was observed. Grey-scale histogram analysis and bimodal segmentation method were used to extract the information about cutting notch from 2D slice images. A 3D model of the stalk was established with reconstruction and volume rendering. Besides, maximum cross-sectional area ratio of cutting notch (MCSARCN) and volume ratio of cutting notch (VRCN) were calculated. The results show that MCSARCN and VRCN had a closely relationship with the cutting force, cutting depth and cutting edge angle according to 3D tomographic images and 2D slice images. Both MCSARCN and VRCN increased with cutting depth, despite of cutting edge angle. For cutting edge angle of 30°, 35° and 40° at different cutting depths, MCSARCN increased from 4.89% to 9.47%, from 8.51% to 22.83% and from 4.30% to 16.87%, respectively. Meanwhile, VRCN increased from 1.59% to 2.13%, from 2.98% to 5.76% and from 3.04% to 5.01%, respectively. When cutting depth was 1.5 mm, cutting force increased but VRCN present a decreased trend with cutting edge angle. X-ray micro-CT could be used to analyze the structure on cutting notch of tea stalks which is helpful in optimizing the structural parameters of the cutter.

Design and Evaluation of Tea-Plucking Machine for Improving Quality of Tea

Abstract. Tea harvesting has always been tedious work. Tea harvesting mechanization is still incomplete in most tea-planting areas. To improve the mechanization of tea plucking, this article introduces a self-propelled track-type tea-plucking machine which mainly consists of a track chassis, an elevator system, a cutting system, and a transmission system. In this article, the structure and functions of the main parts of the self-propelled tea-plucking machine are introduced in detail. Additionally, the rigid body motion model was established. Next, orthogonal experiments (the factors were travel speed and the speed ratio of cutting to traveling) were conducted with three factor levels, and to choose the optimal factor level combination, fuzzy synthesize evaluation was conducted on the results of the orthogonal experiments. The motion model showing that the cutter moves in a cosine law and that the inertia force of the drive shaft and blades also move in a cosine law while working. The experiment reveals that (1) both travel speed and speed ratio of cutting to traveling have a significant effect on the quality (integrity rate, unpicking rate, stubble unevenness) of plucked tea leaves, and (2) the interaction affects only the integrity rate. The fuzzy synthesize evaluation indicates that the optimal factors are as follows: the cutting speed is 0.3 m/s, and the speed ratio of cutting to traveling is 1.0. With this set of parameters, the plucking integrity increased by 20% compared with Japan’s ride-on-type tea-plucking machine. This research made considerable progress in the mechanization of tea plucking, which reduces the cost for employing pickers, enhances the earnings of farmers by improving the quality and price of tea, and supports the sustainable development of tea industry. Keywords: Agricultural machinery, Experiment, Fuzzy synthesize evaluation, Harvest, Hydraulic, Tea.

Development of Navigation System for Tea Field Machine Using Semantic Segmentation

Labor shortage is a critical issue in most of industries, especially in agricultural production. In recent year, riding-type tea plucking machine was imported to provide a relatively high-efficient solution for tea harvesting. However, high-level driving skill is essential. Improper operation may cause damage on tea trees and also lead to mechanical failure. A real-time image-based navigation system may provide an automatic choice to mitigate the difficulties. In this study, deep neural network architectures were applied to semantic segmentation to derive the contours of the tea rows and identify the obstacles in the field scene. Performance of four models including 8s-, 16s-, 32s- of the fully convolutional networks (FCN) and ENet were compared. Considering the overall performance, ENet outperformed other models with the mean intersection over unit (mean IU) of 0.734, the mean accuracy of 0.941, and the inference time of 0.176 s. Furthermore, Hough transform was introduced to obtain the guidelines based on the classification. The average bias of angles and distance were 6.208° and 13.875 pixels, respectively. The preliminary result showed the feasibility of using the developed navigation system for field application. To achieve higher precision, images that cover a diverse scenario in the field were being collected and trained in future work.

Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164mg/L), in comparison to later harvested green teas (11,961mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

Association between Empirically Estimated Monsoon Dynamics and Other Weather Factors and Historical Tea Yields in China: Results from a Yield Response Model

Farmers in China’s tea-growing regions report that monsoon dynamics and other weather factors are changing and that this is affecting tea harvest decisions. To assess the effect of climate change on tea production in China, this study uses historical weather and production data from 1980 to 2011 to construct a yield response model that estimates the partial effect of weather factors on tea yields in China, with a specific focus on East Asian Monsoon dynamics. Tea (Camellia sinensis (L.) Kunze) has not been studied using these methods even though it is an important crop for human nutrition and the economic well-being of rural communities in many countries. Previous studies have approximated the monsoon period using historical average onset and retreat dates, which we believe limits our understanding of how changing monsoon patterns affect crop productivity. In our analysis, we instead estimate the monsoon season across China’s tea growing regions empirically by identifying the unknown breakpoints in the year-by-province cumulative precipitation. We find that a 1% increase in the monsoon retreat date is associated with 0.481%–0.535% reduction in tea yield. In the previous year, we also find that a 1% increase in the date of the monsoon retreat is associated with a 0.604% decrease in tea yields. For precipitation, we find that a 1% increase in average daily precipitation occurring during the monsoon period is associated with a 0.184%–0.262% reduction in tea yields. In addition, our models show that 1% increase in the average daily monsoon precipitation from the previous growing season is associated with 0.258%–0.327% decline in yields. We also find that a 1% decrease in solar radiation in the previous growing season is associated with 0.554%-0.864% decrease in tea yields. These findings suggest the need for adaptive management and harvesting strategies given climate change projections and the known negative association between excess rainfall and delayed monsoon retreat on tea quality and yield.

Developing Situation of Tea Harvesting Machines in Taiwan

In recent years rapid social change and industrial and commercial development in Taiwan has lead to migration of rural labor, population ageing, high wages and labor shortages, which resulted in significant problems for the tea industry. Thus, mechanization in the tea industry emerges as the direction for the future. According to a survey, tea harvesting and tea manufacturing use 87% and 5% of available labor, so the mechanization of tea harvesting is a priority. The application and development of tea harvesting machines worldwide and especially in Taiwan in recent years is investigated in this paper. Recommendations are made for the implementation of tea harvesting machinery in Taiwan in the future. This report may also used as a reference for the use of mechanical harvesting.

Effect of Sunlight Exposure and Different Withering Durations on Theanine Levels in Tea (&amp;lt;i&amp;gt;Camellia sinensis&amp;lt;/i&amp;gt;)

Theanine is a non-protein amino acid representing as much as 50% of the total amino acids in black tea and 1% - 2% of dry weight in green tea. It has been shown to be able to reduce high blood pressure, promote relaxation, and inhibit caffeine’s side effects among others. This current study explored the effects of sunlight and withering durations on theanine levels in tea shoots. Theanine content from three leaves and a bud, two leaves and a bud and internodes were detected and quantified by using High Performance Liquid chromatography (HPLC). Sunlight exposure experiment was started at dawn (0600 HRS, GMT + 3.00) when the light intensity was low and tea was collected at three-hour interval throughout the day to (1800 Hrs, GMT + 3.00) when the light intensity had dropped. At the start of the experiment, the theanine levels were significantly high but as the intensity of sunlight increased during the day there was a significant drop in theanine levels, and as the sun set the theanine levels increased significantly again in all samples. The results also showed that theanine levels were significantly increased after 15 hours of withering. Three leaves and a bud withered for 3 hours had mean theanine levels of 1.41% and those withered for 15 hours had mean theanine levels of 3.11%. Internodes exhibited higher mean theanine levels than those of leaves. In the light of these results, it’s evident that withering for a longer period of time and harvesting of tea when the light intensity is low ensure high amount of theanine in tea.

Impact of modernization of harvesting in tea plantation to improve the productivity and quality (Camellia spp.)

Hand plucking is throughout to be the best method of tea harvesting and has evolved with the tea industry to improve the productivity and quality. With good training of pluckers, a high degree of shoots selectively can be achieved and damage to the tea bush is minimal. Where manual labour is in short supply and mechanical methods of harvesting tea have of necessity been considered. Shear harvesting, as an alternative method to machine harvesting. The green leaf biochemical constituents and quality parameters of black teas changed with method of harvesting. Integrated shear harvesting teas were very rich in their green leaf biochemical precursors and had higher contents of black tea quality constituents than machine harvesting tea. The quality decline was mainly due to mechanical injury and non-selective plucking with machine harvesting. However, tea obtained by mechanical harvesting to continuously field over a prolonged period quality was found to be better, but productivity was declined and physiology of the bush affect when machines are not properly used for harvesting.

Carpal tunnel syndrome in manual tea harvesters

This study aims to present the physiopathological and surgical aspects of carpal tunnel syndrome (CTS) related to manual tea harvesting based on nerve conduction studies and clinical scoring systems. Clinical and neurophysiological scores as well as clinical and occupational variables were statistically analyzed using Boston questionnaire, modified criteria of Italian CTS study group, and modified neurophysiologic grading system of Italian CTS study group in 56 agricultural laborers who underwent surgery due to severe CTS. A statistically significant correlation was found among the clinical stages of the patients and age, working duration and duration of symptoms. There was a statistically significant relationship among neurophysiologic grades of the CTS in patients and the duration of symptoms and functional outcomes before and after surgery. We concluded that manual tea harvesting might be an occupational risk factor for work-related CTS development. Surgical treatment of CTS among manual tea harvesters revealed satisfactory results.

MAINTAINING QUALITY OF JAPANESE-STYLE GREEN TEA AFTER HARVEST

Green tea (camellia sinensis var. sinensis) is an established crop around the world. However, local factors in the development of the green tea industry in Australia meant that we needed to understand and manage quality changes in freshly harvested green tea before processing. Japanese-style green tea is processed (steamed and dried) as soon as possible after harvest. In this study we examined the effect of delaying processing at different storage temperatures and cooling rates. The results consistently showed that freshly harvested green tea shoots had a very high rate of respiration. Most of this energy is released as heat; hence high temperatures are generated by freshly harvested green tea shoots. Postharvest cooling is therefore essential to remove this respiration heat. In this study, different types of cooling were investigated. The results offer some potential for the short term storage of freshly harvested shoots. The effect of lower storage temperatures on leaf quality showed that the lower temperatures reduced the rate of deterioration in physical appearance of the shoots. The effect of the lower storage temperatures on green tea quality showed there were no differences between treatments as measured by the standard AF system using the near infra red (NIR) determination of the final green tea product. However, the quality of final tea will decline if excessive time and temperatures are experienced by freshly harvested green tea shoots before processing. The measurement of the individual components of green tea quality before processing showed that the lower storage temperature maintained the chemical composition of the harvested shoots within the first 24 hours of storage at 3°C. But these quality attributes (total catechins and theanine content) declined by 48 hours storage indicating loss by oxidation and polymerisation. This short window of storage within the first 24 hours after harvest provides some opportunities for further investigation. These results confirm the necessity for adequate postharvest handling and logistics in green tea harvesting and processing.

Relationship between microclimatic factors and yield of spring tea[&lt;I&gt;Camellia sinensis&lt;/I&gt; (L.) O. Kuntze] in Henan Jigongshan Nature Reserve

小气候因子对春茶产量有着重要影响, 建立其相关关系可以更好地为春茶的生产管理服务。本文测定记录了春茶生产期间18个小气候因子及每天茶叶的产量, 应用多元统计分析方法建立了春茶产量与小气候因子的回归模型, 并对茶树生长的小气候因子进行聚类分析和因子分析, 以找出决定春茶产量的小气候因子及其组合。结果表明, 春茶产量与大多数小气候因子间具有显著的线性回归关系, 可以此对春茶产量进行预测预报。另外, 采用逐步回归方法剔除次要的自变量因子, 保留对春茶产量影响较大的小气候因子, 最少可用7个自变量进行回归拟合。聚类分析可以把茶园小气候因子划分为表征水、热特征的4类。因子分析也表明, 温度、水分及其组合是诸环境变量的公因子, 具有较大的载荷。研究表明, 采用较少的环境因子, 回归模型仍具有显著性, 这样可有效降低环境因子的监测和生产管理成本, 为有计划地安排春茶生产和提高经济效益服务。

Noise exposure and hearing conservation for farmers of rural Japanese communities

Agricultural mechanization in Japan has progressed dramatically since 1955 with the introduction of tractors, harvesters, and processing machines. These technological developments have resulted in an increase in exposure to sources of noise that are not only annoying, but damaging to hearing. The present study was undertaken to determine, whether Japanese farmers are at risk for noise-induced hearing loss in comparison with office workers, and by evaluating the present conditions regarding occupational noise levels among agricultural workers. The results suggest that farmers, especially male farmers, have a high prevalence of hearing loss in the higher frequency ranges. Daily noise exposure levels in L Aeq ranged from 81.5 to 99.1 dBA for tea harvesting and processing, and from 83.2 to 97.6 for sugar cane harvesting. Taking into account their rather long working hours and excessive noise from farm machinery, it is concluded that farmers are at risk for noise-induced hearing loss. These findings clearly indicate a strong need for implementation of hearing conservation programs among agricultural workers exposed to machinery noise.

The impact of mechanization of tea harvesting on the quality of south indian CTC teas

The chemical quality parameters and sensory evaluation of black teas changed with method of plucking. Hand-plucked teas were very rich in their green-leaf biochemical precursors and had higher contents of made-tea quality constituents than shear-plucked teas. The quality deterioration was mainly due to mechanical injury and non-selective plucking with shear-harvesting. However, tea obtained by shear-harvesting from a continuously sheared field over a prolonged period was found to be superior. The use of shears reduced the yield and increased the plucking average with a net decrease in cost of production compared to hand plucking.

Occupational noise exposure and blood pressure: Longitudinal and cross-sectional observations in a group of underground miners : P. A. Hessel, G. K. Sluis-Cremer, Archives of Envimnmental Health, Vol. 49, No. 2, 128–134

Agricultural mechanization in Japan has progressed dramatically since 1955 with the introduction of tractors, harvesters, and processing machines. These technological developments have resulted in an increase in exposure to sources of noise that are not only annoying, but damaging to hearing. The present study was undertaken to determine, whether Japanese farmers are at risk for noise-induced hearing loss in comparison with office workers, and by evaluating the present conditions regarding occupational noise levels among agricultural workers.The results suggest that farmers, especially male farmers, have a high prevalence of hearing loss in the higher frequency ranges. Daily noise exposure levels in LAeq ranged from 81.5 to 99.1 dBA for tea harvesting and processing, and from 83.2 to 97.6 for sugar cane harvesting. Taking into account their rather long working hours and excessive noise from farm machinery, it is concluded that farmers are at risk for noise-induced hearing loss. These findings clearly indicate a strong need for implementation of hearing conservation programs among agricultural workers exposed to machinery noise.

The Mitchell cotts tea combine

This paper describes the development and testing of a tea combine for use in Uganda, East Africa, from the prototype in 1982 to the improved Mk 2 machines in 1987 and on to the proposed Mk 3 developments in 1988. When the company returned to its tea estates in Uganda in 1981, there was a considerable labour shortage. With the Governments' encouragement it was decided to introduce tea harvesting machines on the suitable areas of the rehabilitated estates. The machine the company developed is capable of plucking 120 ha/a which is equivalent to the output of about 150 manual workers plucking in the traditional manner. At present four machines are working, the oldest one having completed more than 4000 h. Further machines are being introduced both on this estate and on some of the other company estates in Uganda but from a different manufacturer. The economic performance of the machines will be investigated by the Company during 1989/1990.

The Mitchell Cotts tea combine

This paper describes the development and testing of a tea combine for use in Uganda, East Africa, from the prototype in 1982 to the improved Mk 2 machines in 1987 and on to the proposed Mk 3 developments in 1988. When the company returned to its tea estates in Uganda in 1981, there was a considerable labour shortage. With the Governments' encouragement it was decided to introduce tea harvesting machines on the suitable areas of the rehabilitated estates. The machine the company developed is capable of plucking 120 ha/a which is equivalent to the output of about 150 manual workers plucking in the traditional manner. At present four machines are working, the oldest one having completed more than 4000 h. Further machines are being introduced both on this estate and on some of the other company estates in Uganda but from a different manufacturer. The economic performance of the machines will be investigated by the Company during 1989/1990.

Teste de hipótese de dependência em dados de colheitas de chá para análise da variância

No presente trabalho, verificou-se a possibilidade de utilizar como repetição, para análise da variância, dados de colheita de 55 clones de chá (Camellia sinensis (L.) O. Kuntze) existentes na coleção da Estação Experimental de Pariquera-Açu, do Instituto Agronômico. A hipótese de uma estrutura de dependência que permite o uso de métodos clássicos de análise da variância foi confirmada nos dados de colheitas da coleção, com o uso do teste W², proposto por Baldessari &amp; Soccorsi. Na comparação múltipla de médias, observou-se a separação de dois grupos clones com relação à produção de folhas verdes.