Pacific Millennium Greenhouses, in Ladner, British Colombia, Canada in a recent year had the highest reported annual production of tomatoes in the world at 75 kg per square meter.
This translates to 750,000 kg per hectare, or 330,000 tons per acre!
Crops are grown for 11 months, and the plants are 40-50’ long when taken out.
They grow in narrow bags of yellow cedar 1 meter long.
Capitalization and running costs are astronomical, with the greenhouse itself costing $1,000,000 per acre. Some growers have 30, 40, and 50 acres under glass.
Boilers are run 24 hours per day, and cost almost $500 per day per acre.
Irrigation is initiated based on the kilojoules of light measured by sophisticated sensors, and on a hot day, tomatoes or cucumbers will be irrigated 50 times per day.
Some greenhouses have walls 5 meters high (16+ feet), to assure even temperatures on the plants.
Insect control is accomplished by the use of beneficial predator insects.
Fungus diseases, such as powdery mildew, are controlled by electrolysis of the water. The water is separated into two types – anolyte and catholyte. The anolyte water stops powdery mildew in its tracks without damaging or destroying beneficial life forms. The catholyte water is used for other purposes.
They “grow by the numbers”, dialing in changes based on lab reports sent from the Netherlands Labs. Tissue analysis is no longer done, but irrigation and wastewater are tested for symptoms.
CO2 is maintained at 1200 parts per million, which maximizes plant activity and growth.
Pruning is managed carefully to maintain circulation under and through the leaf canopy.
Profit margins are extremely tight, and the industry is vulnerable to supply-demand fluctuations and cost increases.
(Blair McHenry, consultant to the industry – 2/27/04)