Archive for February, 2011

Tea and North East India

The Organic Green Tea from NE Hut is as good as it gets from the Barak Valley region. Here’s why:

Tea requires a moderately hot and humid climate. Climate influences yield, crop distribution and quality. Therefore, before cultivating tea in a new area, the suitability of the climate is the first point to be considered. Tea grows best on well-drained fertile acid soil on high lands.

Climatic factors

Rainfall: The average annual rainfall in North East India ranges from 2000-4000 mm. However, more than the total amount, the distribution of rainfall matters a lot for sustained high yield of tea throughout the season. In the North East India, the rainfall distribution is not even. The excess rainfall in the monsoon months of June-September causes drainage problems. The average monthly rainfall during November to March is less than the evapotranspiration loss and the resulting soil moisture deficit affects tea bushes. If this dry spell persists for a longer period, tea plants suffer heavily and crop goes down in spite of having sufficient rainfall in the monsoons. Thus, adequate rainfall during winter and early spring is crucial for high yield. Seasonal variation of rainfall (long-term average) is given in the following table:

Average rainfall distribution in the North East India’s tea growing regions in mm

Season
UA
CA
NB
BV
Dooars
Terai
Darjeeling
Winter (Dec-Feb)
4
3
3
3
1
1
2
Pre-monsoon (Mar-May)
24
27
19
28
14
13
15
Monsoon (June-Sep)
66
63
72
62
79
82
77
Post-monsoon (Oct-Nov)
6
7
6
7
6
4
6
Total
2720
2065
2185
3000
3990
2965
2345

(UA: Upper Assam, CA : Central Assam, NB : North Bank, BV : Barak valley)

Temperature and RH : Temperature affects tea yield by influencing rate of photosynthesis and controlling growth and dormancy. In general, the ambient temperature within 13°C and 28-32°C is conducive for growth of tea. Maximum ambient temperature above 32°C is unfavourable for optimum photosynthesis more so if it is accompanied by low humidity. In the tea belts of this region, the average winter minimum temperature (Dec-Feb) remains below 12°C and there is hardly any growth during this period. Flushing commences from March with the rise in temperature. Winter dormancy however is the result of interaction of short day length and low temperature. Low temperature causes slower growth and low yield in the hill district of Darjeeling in comparison to the plains of Dooars and Assam. A humid climate and high RH favours growth of tea.

Day length: Day length influences growth and dormancy in tea bushes. When days of less than 11hr 15 min duration last for at least six weeks tea bushes become dormant. Hence the length of growing season decreases with increasing distance from the equator. Seasonal dormancy appears from around 18° North and South latitudes. In the Northeast India (25°-27°N latitude), the teabushes remain dormant during the winter season for about 3 months on account of the combined effects of short days and low temperature.

Soil

Tea grows well on high land well drained soils having a good depth, acidic pH in the range 4.5 to 5.5 and more than 2% organic matter. Shallow and compacted sub-soils limit root growth. Tea plants growinn on such soils are liable to suffer from draught during dry period and water logging during the rainy months. There should not be any hard pan or concretions in the subsoil within 2m depths. The depth of ground water table should not be less than 90 cm for good growth of tea. Catchment planning is required for improved soil and water management practices in a tea estate for which land survey designed to identify all major and minor topographical features needs to be carried out.

Article Courtesy: http://www.tocklai.net/Cultivation/index.aspx

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February 2, 2011 at 5:15 am Leave a comment

History of Green Tea

Tea consumption has its legendary origins in China of more than 4,000 years ago.[20] Green tea has been used as both a beverage and a method of traditional medicine in most of Asia, including China, Japan, Taiwan, Vietnam, Korea and Thailand, to help everything from controlling bleeding and helping heal wounds to regulating body temperature, blood sugar and promoting digestion.

The Kissa Yojoki (Book of Tea), written by Zen priest Eisai in 1191, describes how drinking green tea can have a positive effect on the five vital organs, especially the heart. The book discusses tea’s medicinal qualities, which include easing the effects of alcohol, acting as a stimulant, curing blotchiness, quenching thirst, eliminating indigestion, curing beriberi disease, preventing fatigue, and improving urinary and brain function. Part One also explains the shapes of tea plants, tea flowers, and tea leaves, and covers how to grow tea plants and process tea leaves. In Part Two, the book discusses the specific dosage and method required for individual physical ailments.

Article Courtesy: http://en.wikipedia.org/wiki/Green_tea

February 2, 2011 at 4:51 am Leave a comment

Health Benefits of Organic Green Tea

Green tea contains salubrious polyphenols, particularly catechins, the most abundant of which is epigallocatechin gallate. Green tea also contains carotenoids, tocopherols, ascorbic acid (vitamin C), minerals such as chromium, manganese, selenium or zinc, and certain phytochemical compounds. It is a more potent antioxidant than black tea,[12] although black tea has substances which green tea does not such as theaflavin.

In vitro, animal, preliminary observational, and clinical human studies suggest that green tea can reduce the risk of cardiovascular disease, dental cavities, kidney stones, and cancer, while improving bone density and cognitive function. However, the human studies are inconsistent.[12]

Green tea consumption is associated with reduced heart disease in epidemiological studies. Animal studies have found that it can reduce cholesterol. However, several small, brief human trials found that tea consumption did not reduce cholesterol in humans. In 2003 a randomized clinical trial found that a green tea extract with added theaflavin from black tea reduced cholesterol.[13]

A study performed at Birmingham (UK) University, showed that average fat oxidation rates were 17% higher after ingestion of green tea extract than after ingestion of a placebo.[14]Similarly the contribution of fat oxidation to total energy expenditure was also significantly higher by a similar percentage following ingestion of green tea extract. This implies that ingestion of green tea extract can not only increase fat oxidation during moderately intensive exercise but also improve insulin sensitivity and glucose tolerance in healthy young men.

A study performed at the Queen Margaret University, Edinburgh looked at the effects of short term green tea consumption on a group of students between the ages of 19–37.[15]Participants were asked not to alter their diet and to drink 4 cups of green tea per day for 14 days. The results showed that short term consumption of commercial green tea reduces systolic and diastolic Blood Pressure, fasting total cholesterol, body fat and body weight. These results suggest a role for green tea in decreasing established potential cardiovascular risk factors. This study also suggests that reductions may be more pronounced in the overweight population where a significant proportion are obese and have a high risk of cardiovascular disease.

In a study performed at the Israel Institute of Technology, it was shown that the main antioxidant polyphenol of green tea extract, EGCG, when fed to mice induced with Parkinson’s and Alzheimer’s disease, helped to protect brain cells from dying, as well as ‘rescuing’ already damaged neurons in the brain, a phenomenon called neurorescue or neurorestoration. The findings of the study, led by Dr. Silvia Mandell, were presented at the Fourth International Scientific Symposium on Tea and Human Health in Washington D.C., in 2007. Resulting tests underway in China, under the auspices of the Michael J. Fox Foundation, are being held on early Parkinson’s patients.[16]

A study [17] performed at the National institute of Chemistry in LjubljanaSlovenia, demonstrated that EGCG from green tea inhibits an essential bacterial enzyme gyrase by binding to the ATP binding site of the B subunit. This activity probably contributes to the antimicrobial activity of green tea extract and may be responsible for the effectiveness of green tea in oral hygiene.

In a recent case-control study of the eating habits of 2,018 women, consumption of mushrooms and green tea was linked to a 90% lower occurrence of breast cancer.[18]

A recent study on rats at the University of Hong Kong, published in the February issue of Journal of Agricultural and Food Chemistry, found that the catechins in green tea were absorbed by the lensretina and other parts of the eye.[19] The absorbed catechins reduced oxidative stress in the eye for up to 20 hours, suggesting that green tea may be effective in preventingglaucoma and other diseases of the eye.

Article Courtesy: http://en.wikipedia.org/wiki/Green_tea

February 2, 2011 at 4:42 am Leave a comment


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