Camellia for Foliage, Flowers, Fruit & Tea
Riwaka: Department of Scientific and Industrial Research. (The research arm of the Motueka venture)
Trials at Riwaka were set up initially by the founder of the Motueka Co-op but the Japanese were in it from the start and it was they who pulled the plug on the trials in the finish.
The Riwaka trials put in 1,200,000 cuttings and it took 5 years to the first pluck. Time from cutting-strike to planting out compared well to Japanese yardsticks. Cuttings were kept in a shed and treated with seradix hormone, then planted direct into the ground. The cuttings were undercut with machine with very few losses, and tops were trimmed to 20 cm. The bed width was 1.8m and there was 8-9" between plants. The variety used was a clone of Yabukita put in at 18,000 to the ha. Scale insect was controlled with Supracide. High pH is a problem to some varieties but, if calcium was needed, this was supplied via gypsum. (JJ - have I got that bit right??) Phytophora is a problem in high rainfall - Riwaka gets 1200 mm p.a. Frost problems might have been overcome had 2 x 10 metre high fans been installed, but local planners would not allow this. Because of ozone depletion New Zealand does not suffer from frost pockets in the same way as the UK, but equally day time heat will evaporate more rapidly than it does in a northern hemisphere climate.
Harvesting was carried out with a single row harvester. The crop was put into 80% shade for 5 days before harvest. There were 2 cuts per year, up to 50 days apart, but the first had by far the better quality.
The time from harvest to factory was less than 4 hours. The factory process consisted of a series of heating and curling operations according to the authority Takeo. (His book is entitled Tea: Cultivation to consumption: green and fermented tea. Chapter 13 pp 413-457. (eds K C Willson and M N Clifford) published by Chapman and Hall in 1992).
Takeo states that plucked leaves are steamed for 45-60 seconds, then curled and dried in hot air at 90-110oC for 40-50 minutes. This primary drying and rolling process reduces moisture content from about 76% to 50%. Leaves are then rolled for a further 15 minutes without heat and then pressed and dried for 30-40 minutes in hot air at 50-60oC. This secondary drying reduces moisture content to about 30%. A further curling is followed by the third drying stage at which leaves are dried directly on a hot pan at 80-90oC and twisted for 40 minutes under pressing and rolling by a curling hand mounted on a fan.
Finally the tea leaves are dried at 80oC until a moisture content of 6% is achieved. This results in a fine needle like form of sencha (type of Japanese green tea product). Final cleaning and grading to remove dust and stalks then takes place. The product needs vacuum packing for export.