In my 8 short years of becoming a tea nerd, I find myself constantly looking up the meaning of certain terms used within the industry. I think my favorite term is “flush” but that’s because I have the maturity level of a 6th grade boy. Thankfully, after a discussion at World Tea Expo 2013 with some of my favorite tea nerds, it turns out I’m not the only one that is confused by the terms: Varietal, Cultivar and Clone. If you, like me, enjoy clarity and sounding uppity about tea, this is the article for you! And a huge thank you to Michael Coffey (a.k.a. The Tea Geek) for providing the insight and wisdom! –Naomi Rosen
***This is the second installment in a four part series discussing ideal tea growing conditions. For Part 1, please click here.
Marginal conditions occur when one or more of these ideal growing conditions is not met and where major corrective action needs to be taken to obtain a commercial yield. The symptoms of marginal conditions, however, vary from the obvious to the hidden, and the effects from debilitating to death. In the last 100 years of science based tea growing we have learned many techniques for minimizing the effects of less than ideal conditions – irrigation, shading, fertilizer, land drainage, soil acidification, all spring to mind – but be aware that though effective such techniques increase the cost of production, so have to be factored into your business plan.
Some examples and typical remedies for common marginal conditions are illustrated below under the heading Climatic. Soil Conditions and Genetic options will be covered in a future post.
a) Altitude/Latitude. The ideal conditions for Camellia sinensis, and particularly var. assamica, are found at high elevation (6000 ft) in equatorial latitudes. High altitude is always assumed to be best – “good teas come from high elevations” – but while this is true for quality it is not necessarily so for profit as yield often drops as quality increases. Even in Kenya yield is very altitude dependent (Stephens showed a 50% higher yield at 5,500 ft compared with 7,000 ft in the Kericho district of Kenya) and, increasingly, climatic conditions become marginal for growth as the latitude extends north and southwards. Thus, the most suitable height for growth declines away from the equator – 5,500 ft at 0 deg, 3,800 ft at 7 deg N, 2,500 ft at 15 deg N and around sea level above 30 deg. Latitude 40 deg N and S is about the limit for commercial tea, with marginal growing areas descending to sea level elevation – Turkey, Georgia, Tasmania – and then only using the cold hardy China jats with a six month season. Cold tolerance (this keeps your bushes alive) and season extension (this improves commercial yield) must rely on future cold tolerance breeding to overcome extreme temperature marginality.
Latitude for a given altitude affects daylength, light intensity and temperature, with local modifications depending on sea proximity. For example the embryo tea industry in North Pakistan at 36 deg N contends with frost and snow in winter, with cold dormancy between October and April but with drought and 100°F plus day temperatures before the July monsoon. The growing season is 180 days at 3,000 ft, but shortens to 165 days at 4,000 ft with a yield reduction of 10%. In this area the smallholder farmers can only grow frost hardy China types (raised as VP clones) as the Assam types die in the nursery despite using double layers of polythene as winter insulation.
b) Drought. Many tea growing areas suffer from a shortage of rain, poor rain distribution, and drought. In Pakistan for example the annual rainfall is marginal at 49” (last 5 year average) and not equally spread (the monsoon contributes 40% of this amount during six weeks). There is a hot drought in June, and cold drought in November. Also, there are extreme cyclic climatic variations to contend with. When originally tested for tea growing the 10 year average was suitable for tea at 65”.
Lack of water also reduces air humidity to the extent that bud growth is limited – no buds means no leaf which means no profit. The saturation deficit can rise to 7 kPA in the hot dry unproductive period in Malawi. Irrigation may be given in these rainfall marginal conditions (assuming water is available, suitable in quantity and in pH) but irrigation will not entirely replace natural rainfall neither can it adequately replace humidity. The type of irrigation employed (static or moving sprinkler, furrow, flood, drip) will influence its efficacy and cost.
b) Frost and Hail. These are adverse but intermittent climatic effects. Frost often affects areas edging into climatic marginality. The higher elevations in Kenya get frosted in spring as does the early season in Japan. Alleviation varies from thatching bushes with grass – used for example on young tea in the hills of Nepal and Darjeeling, to electric frost fans, used in Japan to circulate and mix the air over tea bushes at night. The use of suitable genetic material – China types rather than the broad leaved assamica – can also reduce frost damage.
Hail causes heavy losses of young flush (estimated to an average 10% of crop loss in Kenya). Very large hail cannon have been used for protection in South Africa – to drop hail away from the tea estate – but not particularly successfully.
Geoff Norman, of Steep Stories, has had a busy tea summer. One of his trips involved some hands on tea picking/processing at the beautiful Sakuma Brothers in Burlington, WA with our Canadian brethren. Per Geoff, “There’s nothing more fulfilling than picking your own leaves.” On a side note, yet another argument for Agri-Tourism…just sayin’!
– making a success of marginal conditions
Tea is a crop that grows like a weed under ideal conditions and on ideal land, but very few of us are in that fortunate position. Under more marginal conditions it takes some skill and expertise to grow it well. The variation in tea yields across the world demonstrates this: as low as 1/4 ton/acre of Made Tea in China and Indonesia (smallholder farmers), and as high as 1 ton/acre for Indian estates, to (exceptionally) the world record of 4.5 tons/acre for Clone S15/10 in Kenya. Between these wide yield extremes lie some marginal conditions, poor planting material, and some lack of expertise.
What does tea require to do well? In terms of climate, the Teaman’s (or Teawoman’s) ideal would be misty at night, sunny during the day, with rain at tea-time – and not too much cold weather, hail or drought. More specifically for ideal growth tea requires:
- Average air temperature 70 to 95°F – growth becoming dormant if night temperatures are below 50-55°F
- Soil temperature between 60 and 75°F
- Annual rainfall between 1,500 and 3,500 mm (60 and 140 inches), well spread through the growing season
- Soil pH between 4.5 and 5.5
- Soil structure: well drained but retentive. The tea crop can evaporate 3 to 6 mm per day = 1,000 to 2,000 mm per year. Rainfall is therefore marginal below 1,500 mm (60”).
- Water table more than 6 ft below soil surface
- Humidity: high enough not to limit shoot growth (in scientific terms this means a saturation deficit remaining below 2.3 kPA)
- Light intensity: at least 700 to 800 W per m2 – this is typical of winter sun intensity in tropics = 75% of summer levels. Yet of this, only 40 w/m2 will be wasted by reaching the ground under healthy bushes. Tea grown well is an extremely efficient light interceptor but low planting densities, poor pruning techniques and vacancies waste sunlight – and reduce yield.
Instead of Get ‘er Done, we encourage you to Get yer DUNS…
In our blogs to date, we have covered many topics, but one was how to apply for a USDA grant and we have touched on other government (federal and state) programs. If you decide to go at it alone and not involve a university or other organization (which I think is a BAD idea at this point in individual progress of the US Grown Tea Movement), you will need to get a DUNS number assigned to the business or organization that you will be using to apply for the grant.
The DUNS number will also be required if you are planning on applying for a US Small Business Administration loan or grant. It is also used by creditors when determining deposits, interest rates, insurance premiums, and many other things thing required in the course of business. It is similar to a FICO score (personal credit score) for a business. Even if you are NOT applying for government assistance, some banks and insurance companies will require you to have a DUNS number. Even if it is not REQUIRED, it is a wise idea because unlike a FICO score, you can “manage” your DUNS interface by keeping it up to date, possibly saving you a lot of money on insurance premiums, percentage rates, utility deposits, and numerous other ways.
A DUNS number is NOT the same as a federal/state tax identification number. A DUNS number differs from a tax identification number because, if there is more than one physical location or address for your business/organization, then you will need to apply for a DUNS number for EVERY location. If you operate multiple businesses/organizations out of one address, you will need to apply for a DUNS number for EVERY business/organization at the address. It is not a “catch all” number for a physical location or a business/organization at large, it is an individualized number for every location and every business and never changes and never is reused. It will remain with that business even if it is ever closed (and we hope that never happens).
DUNS stands for Data Universal Numeric System and is copyrighted by Dunn & Bradstreet (NYSE: DNB). According to the Dun & Bradstreet website, “The D-U-N-S® Number is the linchpin of D&B’s DUNSRight™ patented-quality process. Once assigned, a D-U-N-S® Number is neither reused nor assigned to another business. Used by the world’s most influential standards-setting organizations, the D-U-N-S® Number is recognized, recommended, and/or required by more than 200 global, industry, and trade associations, including the U.N., European Commission, and the U.S. Federal Government.”
A DUNS number is REQUIRED for any transactions with contractors and grantees with the federal government in the US. According to the federal government website at http://fedgov.dnb.com/webform, “The DUNS number is widely used by both commercial and federal entities and was adopted as the standard business identifier for federal electronic commerce in October 1994. The DUNS Number was also incorporated into the Federal Acquisition Regulation (FAR) in April 1998 as the Federal Government’s contractor identification code for all procurement-related activities.”
There is also a very good blog on the process found here: http://www.sba.gov/community/blogs/why-your-business-needs-get-duns-number.
If you need additional assistance, your county agent should be familiar with this process and can help you or you can visit your local USDA office.