Tea Plucking Research Articles

Gender dan Mekanisasi: Pengalaman Pekerja Perempuan Berpartisipasi dalam Kelompok Petik Mesin di Perkebunan Teh Gambung, Jawa Barat

Mechanization in the tea harvesting process commonly leads to gender imbalance, as male workers receive more benefit than female. However, this phenomenon does not the case in Gambung Tea Plantation. Female participation in the machine harvesting is high as they become the operator of tea plucking machines. This phenomenon is worth to study in particular to explore female workers’ personal experience in mechanical tea plucking. This research applies descriptive qualitative method with phenomenology approach. Female and male machine picker becomes the main subject in this study. Primary data were collected through observation, documentation, interviews and Focused Group Discussion with female and male tea plucker. Triangulation techniques were applied to ensure data validity. This study suggests that the mechanization process in Gambung Tea Plantation has created a new gender division of labour where male and female work together in a team to operate the machine. Female workers show quality of work better than male worker. Amidst the efforts of female workers to participate in the mechanization there are risks and constraints for them, such as less-gender friendly equipment, lack of access and control to resources, cultural norms, values in the society.

Analysis of mechanical properties for tea stem using grey relational analysis coupled with multiple linear regression

To improve the picking quality of tea plucking machine, the relationship between mechanical properties of tea stem and their influence factors was studied. Tea variety of Zhongcha 108 was selected as test sample to analyze the grey correlations of stem segment number, stem diameter, stem inter-node distance, moisture content, fracture deflection, moment of inertia, young's modulus, hemicellulose content, cellulose content, lignin content to mechanical properties (bending and shearing strength). Further, multiple parameter optimization and model establishment were performed using partial least squares regression (PLSR), principal component analysis (PCA) + multiple linear regression (MLR), grey relational analysis (GRA) + MLR. The results showed that the cellulose content, bending strength, shearing strength, stem diameter and moment of inertia generally increased with stem segment number. For bending and shearing strength, GRA (0.6) + MLR method was suitable to establish the model. The values of adjusted Rc2 and RMSEC of bending strength were 0.8634 and 3.3264 N, and these values of shearing strength were 0.9730 and 0.2573 N. Besides, adjusted Rp2 values of bending and shearing strength were 0.9443 and 0.9125, RMSEP values were 2.8580 N and 0.7211 N, respectively. The GRA-MLR model is accurate and effective method to investigate the mechanical properties of tea stem for designing a suitable cutting equipment.

Propellants of mechanical pruning and plucking of tea (a case of developing countries)

Tea is one of the most widely consumed natural beverages in the world. High costs of tea pruning and plucking is among the main challenges of its production in Iran as a developing country. Therefore, the development of mechanical pruning and plucking of tea bushes is unavoidable to ensure its sustainable production. In this respect, the present study was carried out in Guilan Province as the leading tea producing region of Iran using Delphi technique in order to identify and analyze the driving factors of the development of tea pruning and plucking mechanization in Iran. After consultation with the academic faculty members in Guilan Province, to form the research panel, 30 experts of tea mechanization were identified and selected from the Tea Organization of Iran, Tea Research Center, and Agriculture Agencies of main tea producing regions of Guilan Province. The results revealed that “Publicizing the benefits of consumption of the domestic tea”, “supporting tea making industries to modernize their systems”, “Reduced prices of domestic and imported mechanical tea equipments by subsidy payment and reduction of tariffs on imports”, “quantitative and qualitative improvement of tea green leaves through applying new agronomic methods and modern irrigation systems”, and “Devoting special bank loans to execute tea mechanization plans” were the most important driving factors of the development of tea pruning and plucking mechanization in Guilan Province as agreed upon by 96.78, 95.89, 95, 95, and 91.42% of panel members, respectively. Thus, recommendations were put forth to help the development of tea pruning and plucking mechanization in Guilan Province.

A strategic analysis of tea leaves supply chain before manufacturing – a case in Assam

PurposeThere exists insufficient literature on classification and taxonomy of tea leaves supply chain (TLSC), so the purpose of this paper is to study the existing TLSCs and classify them accordingly. Apart from this, the paper also focuses on identification of key decisions issues in the supply chains (SC) and developing a TLSC decision framework for the state of Assam in India.Design/methodology/approachThe paper is based on a two-year detailed study on TLSC in Assam which encompasses 22 Tea Estates, 41 Small Tea Gardens (STGs) and a Research Institute (Tocklai Tea Research Institute). Secondary data were collected from relevant websites of various government organizations of India, company’s websites, annual reports, official statements from the companies, tea market reports, annual reports of the Indian Tea Association, the Tea Board of India, Tea Research Institute and published reports, etc.FindingsThe “point of origin” of TLSC is a tea garden, “point of consumption” is considered as a tea factory and green tea leaves (GTLs) forms the basic raw material. This SC includes mainly three players: Tea leaves growers, manufacturers of made tea and tea leaves agents. This study identifies the three types of TLSCs existing in Assam: TLSC1, TLSC2 and TLSC3. Among them, only TLSC1 is both responsive as well as an efficient chain, while the rest are only responsive chains. Later two SCs can be made efficient with the proposed TLSC4.Research limitations/implicationsThere is an insufficient literature on classification and taxonomy of TLSC, therefore the study (considerably the classification and taxonomy of TLSC) was developed from the primary data which were collected from the 22 Tea Estates and 41 STGs of four districts of Assam, because of limited time (two years). The study should have involved more tea estates and small tea gardens for better classification and taxonomy.Practical implicationsThe proposed model suggests that small tea growers may create a co-operative whereby smaller tea gardens (STGs) (members of the co-operative) unite to act as a single large garden, set up their own co-operative factory and recruit permanent tea plucking laborers. This up-gradation of TLSC2 and TLSC3 to TLSC4 may enable a group of STGs to work in a manner similar to a Tea Estate.Originality/valueTo the best of authors’ knowledge this is one of the first studies to classify the TLSC in Assam.

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.

EFFECT OF MECHANICAL HARVESTING ON YIELD AND QUALITY OF TEA IN TANZANIA

SUMMARYHand plucking of tea is labour intensive, and with rising labour costs mechanical harvesting (MH) is of increasing interest. However, effects of MH on yield and quality of tea remain unclear. We harvested two tea clones for eight years with a small, wheeled machine, to investigate effects of different cutting heights on yield and quality. The harvest interval for machine plots was 40% longer than for hand plucking in the first three years and 100% longer thereafter. The yield response, relative to hand plucking, depended on cutting height. Provided that increase in bush height (table rise) was 6 cm per year or less, yields were 15–21% higher than with hand plucking and increased yield was still being maintained after eight years. The increase in yield appeared to be mainly attributable to the longer harvest interval for machine plots, so that larger shoots were harvested. There was no increase in the number of shoots harvested per year, despite more intensive plucking with the machine. In less intensively harvested plots, where table rise was 11–14 cm per year, yield was reduced compared to hand plucking, and shoot number was nearly 30% lower. Dry matter production was greatest under the least intensive harvesting, but greater intensity gave higher harvest index and yield. In plots with no table rise, but not in other plots, a large amount of die-back of plucked points was observed. This may indicate source limitation of shoot numbers. We conclude that, with an extended harvest interval and careful management of cutting height, the yield of tea can be maintained under MH. There was a reduction in green leaf quality, with coarser shoots and increased mature leaf, but a limited number of taster evaluations of quality of the black tea showed significant differences for only one clone.

A Study of Tea Pluckers’ Perception on the Introduction of Tea Plucking Machines in James Finlay’s Kenya

This study sought to assess the perception of tea pluckers on the introduction of tea plucking machines in James Finlay’s Kenya. The research was a case study of one of the major tea industry players; James Finlay’s Kenya Ltd. The target populations were all the tea estates in James Finlay’s (K) Ltd in Kericho County. James Finlay’s has a total of 13 Tea estates. There are a total of 10,262 tea pluckers in the company. A sample of five estates was considered and a sample of 20% of tea pluckers in these estates was taken for the study. A representative group according to Mugenda and Mugenda is one that is at least 10% of the population of interest. The above sample was therefore representative. Data was collected using structured questionnaires and interview methods. The data collected was supplemented with available literature review on the subject of study. The response from cross-functional sample group was analysed using descriptive statistical techniques in form of frequency distribution tables, percentages, pie charts, and computer packages. The study found that the tea pluckers viewed the introduction of the machines negatively; they interpreted it as a way of rendering them obsolete and eventually retrenching them. They therefore did not fully support its implementation

Dissipation kinetics of beta-cyfluthrin and imidacloprid in tea and their transfer from processed tea to infusion

Dissipation kinetics of mixed formulation consisting beta-cyfluthrin and imidacloprid in tea crop under an open field ecosystem was investigated. The mixed formulation was applied on tea plant at recommended (27 + 63) and double the recommended (54 + 126g a.i./ha) dose and residues were determined using gas chromatography-electron capture detector and high performance liquid chromatography-photodiode array detector for beta-cyfluthrin and imidacloprid, respectively. The limit of quantification of analytical method was 0.05µg/g and the average recoveries were ranged from 88.36% to 103.49% with relative standard deviations of less than 6% at three spiked levels. The experimental results showed that in the green tea leaves imidacloprid dissipated faster than beta-cyfluthrin with the half-life ranging between 1.20–1.39 and 2.89–3.15days, respectively. The beta-cyfluthrin residues present in the processed tea not transferred into the tea infusion during the infusion process and imidacloprid transferred in the range 43.12–49.7%. On the basis of the transfer of residues from processed tea to infusion, a waiting period of 17 days for tea plucking after pesticide application at recommended dose may be suggested.

The Impact of Adoption of Recommended Tea Plucking Interval on Tea Yields in Kenya

ABSTRACTThis study employs the endogenous switching regression model to examine the impact of the adoption of recommended tea plucking interval on tea yields among small-scale tea farmers in main tea-growing regions of Kenya. The study utilises cross-sectional farm household level data collected from a randomly selected sample of 413 households. Results support the notion that self-selection occurs and that estimates that do not consider selection-bias would be biased. Different determinants are found to be significant in explaining the tea yields for adopters and non-adopters. Thus, policy makers should consider these differing effects when designing development projects to increase tea yields.

Gender Relation in Tea Plucking Workers: A Case Study of Gender Division of Labour and Gender Relation in Gambung Tea Plantation, West Java

<p>ABSTRACT<br />Men and women’s participation in tea plucking have been divided based on gender and strongly patriarchy-influenced. This division of labor cause a gender relation describes specific case of their relations in tea plantation. This study aims to describe the gender relation among the tea plucking workers at Gambung Tea Plantation, analyzed by qualitative approach, particularly treated as a case study. Data collected by in-depth interviews, observation, focus group discussion, and documentation. It was triangulated and analyzed using Harvard Analytical Framework and Gender Balance Tree in Gender Action Learning System approaches. The result shows that both men and women have equal access employment in plucking tea but their participation divided based on gender and patriarchy-influenced. Women have large participation in manual job description while men dominates on mechanic. Manual labor requires longer working-hour. It cause women have longer on working-hour than men. It is also enhance their burdern, eventhough generally they have double roles. As the consequences, women must work harder on their both roles. However, women’s participation in productive works enable women to generate income that makes them gaining better position within the household, such as a decision maker. It makes them able to access skill capacity.<br />Keywords: gender relation, tea pluckeig worker, tea plantation, Harvard Analytical Framework, Gender Action Learning System</p><p><br />ABSTRAK<br />Partisipasi laki-laki dan perempuan dalam pemetikan teh dibagi berdasarkan gender dan dipengaruhi kuat oleh patriarki. Pembagian kerja ini menimbulkan relasi gender yang menggambarkan kasus tertentu hubungan laki-laki dan perempuan di perkebunan teh. Penelitian ini bertujuan untuk mendeskripsikan relasi gender pada kegiatan pemetikan teh di Perkebunan Teh Gambung, dengan pendekatan kualitatif, dalam studi kasus tertentu. Pengumpulan data dilakukan dengan metode wawancara mendalam, observasi, diskusi grup terpusat, dan dokumentasi. Data ditriangulasi dan dianalisis menggunakan Harvard Analytical Framework dan Gender Balance Tree dalam Gender Action Learning System. Hasil penelitian menunjukkan bahwa baik laki-laki dan perempuan mempunyai akses yang sama dalam pemetikan tetapi partisipasi mereka dibagi berdasarkan gender dan dipengaruhi patriarki. Perempuan mempunyai partisipasi besar dalam pemetikan manual sedangkan laki-laki mendominasi mekanisasi mesin petik. Manual membutuhkan waktu yang tinggi yang menyebabkan perempuan mempunyai waktu kerja yang lebih banyak dari laki-laki dan hal ini menambah beban perempuan yang secara general mempunyai beban ganda. Sebagai konsekuensinya, perempuan harus bekerja lebih keras. Namun, partisipasi perempuan dalam pekerjaan produktif memungkinkan perempuan untuk menghasilkan pendapatan yang memberikan perempuan posisi yang lebih baik dalam rumah tangga, seperti kekuasaan dalam pengambilan keputusan dan posisi tawar dalam mengakses peningkatan kapasitas keterampilan.<br />Kata kunci: relasi gender, pemetik teh, perkebunan teh, Harvard Analytical Framework, Gender Action Learning System</p>

A Comparative Study of Gender Roles in Tea Sector in Embu and Murang’a Counties, Kenya: A Case Study of Smallholder Tea Farmers

<div><p><em>Men and women perform different roles within the household and in agricultural sector. However, women’s roles are more strenuous and more pronounced and they work extra hours in providing the much needed labour on the tea farms than the men counterpart. But in spite of women’s much involvement in agricultural sector, they undergo discrimination in all aspects not only related to land ownership but also kept out when it comes to control and access to the benefits accrued from tea farming. This study therefore sought to determine gender roles in tea production in Embu and Murang’a counties and also to assess the accessibility and control over the benefits accrued from tea farming by gender. Stratified random sampling; simple random sampling and Purposive sampling techniques were used to sample 276 respondents from estimated target population of </em><em>18,000 tea growers from the two counties under study. </em><em>The study established that women perform more roles in tea plantation than their male counterparts. The findings clearly demonstrated that the most tedious and difficult roles that took long hours to accomplish were assigned to the women for instance, the plucking of tea, taking green leaves to the buying centre and collecting/receiving pay slips from the factory or buying centre was majorly done by the women but it’s men who goes to the bank to earn bonus and monthly payments for the work didn’t participate and also attending annual general meetings (AGMs) or any meetings at the factory or buying centre and even organized educational forums and surveys since they knew that at the end of it they would either receive certificate of participation and more importantly sitting allowance. The finding further revealed that, men were assigned themselves roles that lighter duties that might require bit of skills such as pruning of tea bushes and nursery establishment. On the other hand women are unable to attend the forums or meetings because of numerous roles waiting for them ranging from household chores to agricultural production. Although conflicts have been in arise over the control of proceeds of tea sales because men receive the benefits and women who worked for them do not seem to benefit much, this gender discrimination had negatively affected tea production and by extension resulted in decline of tea yields and neglected tea bush. This study recommends that Kenya tea development agency to increase its sensitization forums and conducts regular workshops to educate the tea growers on gender balance in regards to distribution of proceeds from tea sales, access to and control over tea benefits. This could not only help to empower and motivate women but also demystify the gender stereotypes that men have about women and therefore eliminate gender discrimination in tea growing communities.</em></p></div>

Changes in targeted metabolites, enzyme activities and transcripts at different developmental stages of tea leaves: a study for understanding the biochemical basis of tea shoot plucking

Standard plucking of fresh tea leaves is one of the major factors in determining tea quality, apart from processing conditions. Tea quality is a function of metabolite content and declines with leaf maturity. In this work, we studied the metabolic consequences of leaf maturity on tea leaf quality by metabolite profiling. Significant variation in metabolite levels was observed during tea leaf maturation. The concentration of catechin, epicatechin gallate, epigallocatechin gallate and total catechins decreased with leaf maturity while epicatechin and epigallocatechin showed reverse trend. A concentration dependent increase with leaf maturity was noted for cell wall-bound phenolics, which was predominated by gallic acid followed by trans p-coumaric acid. The relative abundance of monoterpenoids declined with leaf age while fatty acid derivative volatiles showed inverse trend. Activities of shikimate dehydrogenase and phenylalanine ammonia-lyase also decreased with leaf age. The transcript levels of flavone-3-hydroxylase and anthocyanidin synthase showed a significant positive correlation with total catechins content. Interestingly, accumulation of total catechin showed significant negative correlation with total fatty acid derivative volatiles, total wall-bound phenolics, chlorophyll and volatile benzenoids during leaf development. This suggests a possible alteration of carbon pool in tea leaf during maturation. We hypothesize that the declination of flavan-3-ols biosynthesis in mature leaves might lead to a shifting of carbon flow in the direction of linked metabolic pathway related to chlorophyll, wall-bound phenolics, benzenoids and fatty acids biosynthesis.

The performance test of plucking machine type 120 at plucking of assamica tea

The rate of increase tea cost production in several tea fields could not be offered by the rate of increase selling price. The fact that the cost of plucking machine is lower than manual plucking has attracted the interest and attention of tea smallholder to change from manual plucking to plucking machine. The plucking machine which were imported from japan was not designed for assamica tea in Indonesia. In order to improving performance of plucking machine, the plucking machine need to be designed with support from the field and  appropriate machine. The aim of this trial was to test the performance of the plucking machine type-120 at plucking of assamica tea with 120 cm of spacing between rows. The plucking type used was medium plucking and kept the Kepel leaves (k +0) in the middle of the bushes using plucking method supported by the garden and the appropriate plucking machine type-120. Results obtained from the test were: (1) The using of plucking machine type-120 with medium plucking, kept the Kepel leaves (k +0), and controlled plucking height did not cause a decrease in plant health, production as well as quality of the shoots. (2) Field work capacity of plucking machine was 1.19 ha/day with work efficiency of 58.2%. (3) The ratio of plucking machine was 0.30/ha with fuel ratio of 0.33 litres/ha. The performance output of the plucking machine could be reached 224 kg/plucker as compared to only 24 kg/plucker when done manually.

Environmental factors influencing aluminium accumulation in tea (Camellia sinensis L.)

Tea is a major dietary source of aluminium (Al) to humans. There is a need to understand how environmental factors influence Al accumulation in tea leaves in order to devise strategies to lower Al intake from tea. Paired soil and tea shoots were collected from 197 micro-locations across 11 tea plantation estates in Kericho, Kenya. The concentrations of Al and other minerals in tea samples and a range of soil properties were determined. Multiple regression analysis was performed to identify environmental variables that significantly affected tea Al concentration. A comparison was made between washed and unwashed tea samples. Tea samples from a long-term lime and elemental sulphur trial were analysed. Four environmental variables were identified as having a significant positive effect on tea Al concentration, including soil dust contamination represented by tea Ti concentration, the age of plantation, the number of years after pruning and Al saturation in topsoil, whereas two variables had a significant negative effect, including the altitude of plantation and rainfall prior to tea plucking. The effect of soil dust contamination was further verified by a leaf washing experiment. Soil pH was found to have no significant effect on tea Al concentration in both the field survey and the lime and sulphur experiment. Liming would not be an effective method to decrease Al concentration in tea. Avoiding soil dust contamination, plucking tea shoots from plantations at higher altitudes or from younger plantations could lower tea Al concentration.

Developing Situations of Tea Plucking Machine

To acquire the developing trend and ways of mechanization of tea plucking, with analyzing the developing backgrounds and situations of tea plucking machine both at home and abroad, this paper obtains the conclusion that there are several countries that have conducted a lot of studies on tea plucking machine, such as Japan, England, France, India, Australia and Argentina. Among others, Japan goes ahead, where lots of researches have been conducted in the highest developing level. The article also analyses the reason why China has a poor mechanization of tea plucking and points out existing problems. Finally, some advices and measures for developing Chinese domestic mechanization of tea plucking are given.

Application of remote sensing and GIS for assessing economic loss caused by frost damage to tea plantations

This study aims to develop a method to evaluate economic loss resulting from damage of spring frost to tea plantations, with the help of remote sensing and geographic information system (GIS) technology. The study site was the Yuezhou Longjing tea producing area in the Shaoxing region of China and evaluated the economic loss resulting from damage to Wuniuzao, Longjing-43 and Jiukeng tea plantations caused by frost on 10 March 2010. Based on a linear equation for representing the variations of each tea tree species with geographical factors, their beginning date of tea plucking (BDTP) were calculated at each grid points with a GIS database. Minimum temperatures were retrieved with four split-window algorithms and satellite remote sensing data was acquired at 06:29 and 12:57 on 10 March 2010. A variational correction method was performed with data from automatic weather stations. Mean absolute error between the retrieved minimum temperatures and actual minimum temperatures of only 0.3 °C was obtained. The BDTP for each species, based on minimum temperature values, and the frost index for each grid point were referenced to assess economic loss resulting from damage to Wuniuzao, Longjing-43, and Jiukeng tea plantations caused by frost. The economic loss estimated in our study was close to the actual value.

Changes in pick beginning date and frost damage risk of tea tree in Longjing tea-producing area

We analyze the pick beginning date and frost damage risk trends of Jiukeng, Longjing-43, and Wuniuzao tea trees with time, using meteorological data from 12 station pairs over the period 1971–2010 in the Longjing tea-producing area. The pick beginning date of Jiukeng, Longjing-43, and Wuniuzao varieties had no statistically significant trends before 1990. The pick beginning date of Jiukeng variety had statistically significant decreasing trends after 1990, and there were no statistically significant trends in the start date after 1990 for Longjing-43 and Wuniuzao varieties. The average pick beginning dates of Longjing-43 and Wuniuzao varieties before 1990 are later than those after 1990 by 3.8–4.8 and 2.0–3.1 days, respectively. We used the trend of difference between beginning date of tea plucking (BDTP) and 0 °C terminal date to analyze frost damage risk trends. Eleven counties had no statistically significant frost damage risk trends for Jiukeng, Longjing-43, and Wuniuzao varieties, leaving only one county with statistically significant trends.

Antiretroviral therapy, labor productivity, and sex

To estimate the impact of antiretroviral therapy (ART) on labor productivity and income using detailed employment data from two large tea plantations in western Kenya for HIV-infected tea pluckers who initiated ART. Longitudinal study using primary data on key employment outcomes for a group of HIV-infected workers receiving antiretroviral therapy (ART) and workers in the general workforce. We used nearest-neighbor matching methods to estimate the impacts of HIV/AIDS and ART among 237 HIV-positive pluckers on ART (index group) over a 4-year period (2 years pre-ART and post-ART) on 4 monthly employment outcomes - days plucking tea, total kilograms (kgs) harvested, total days working, and total labor income. Outcomes for the index group were compared with those for a matched reference group from the general workforce. We observed a rapid deterioration in all four outcomes for HIV-infected individuals in the period before ART initiation and then a rapid improvement after treatment initiation. By 18-24 months after treatment initiation, the index group harvested 8% (men) and 19% (women) less tea than reference individuals. The index group earned 6% (men) and 9% (women) less income from labor than reference individuals. Women's income would have dropped further if they had not been able to offset their decline in tea plucking by spending more time on nonplucking assignments. HIV-infected workers experienced long-term income reductions before and after initiating ART. The implications of such long-term impacts in low-income countries have not been adequately addressed.

静岡県の初発地区の茶園におけるチャトゲコナジラミ成虫の発生消長

In 2011, we used yellow sticky traps to investigate seasonal changes in adults of the exotic pest Aleurocanthus camelliae Kanmiya and Kasai in tea fields where the pest was first discovered in Shizuoka Prefecture, Japan. The pest was discovered for the first time in the Kikugawa region in October 2010, and subsequently in the Iwata region in November 2010. From April to November 2011, monitoring traps were set in three fields in Kikugawa and two fields of Iwata. In all the fields investigated, captures of adults showed the following four peaks: the beginning of May, the middle of July, the beginning of September, and the middle or end of October. In each area, the first and second peak days were the same in each field, although the third and fourth peak days varied among fields within the same area. Pruning after the first plucking of tea suppressed the occurrence of the pest during the following 2 or 3 months.