Issue 94: Field Vs Glasshouse Tomatoes

May/June – 2007
Author: Graeme Smith

GRAEME SMITH compares production statistics for field-grown and glasshouse tomato production.

In response to a detailed article published in Good Fruit & Vegetables (January 2007) on growing field tomatoes in the Goulburn Valley, Victoria, for the fresh table market, the Australian Hydroponic & Greenhouse Association (AHGA) has made a direct comparison with tomato production in a modern glasshouse situated only a few kilometres away, therefore experiencing exactly the same climatic conditions.

The following actual production figures of both field and glasshouse are from the last growing season and are converted to a 1 hectare rate (10,000sqm) so that direct comparisons can be made.

As can be seen by these actual production figures, modern glasshouses using closed and controlled production systems are truly the modern face of horticulture and deliver far superior results in terms of quantity, quality, water use and market returns.

When reviewing the production figures, it appears on the surface that greenhouse production uses more water than field production, however it’s worth noting greenhouse production occurs over 111/2 months compared to 7 months for field production. The conservative greenhouse production figures also include all water used, not just that put on crops (i.e. fogging, roof sprinklers, hand washing, staff facilities, etc.). The important point is the conversion rate of water used to tomatoes produced, and it shows greenhouse production clearly in front (500%+).

The 500+% water efficiencies alone (grams fruit per litre of water) should encourage all tiers of government to invest in greenhouse R&D to better utilize our ever dwindling water resources for a vast range of greenhouse crops.

These figures clearly show why leading supermarket chains have signalled to industry their intention to increase greenhouse tomato sales from the current estimated 17% (of fresh table market), to 50% over the next 5 – 8 years. This is a tripling of one sector of the greenhouse industry alone!

Industry expects that the same growth pattern will occur for other greenhouse crops like capsicum, eggplant, cucumber, lettuce, Asian vegetables, strawberries, etc.

There are many reasons why growers should look to protected cropping as outlined here, but other compelling reasons include the following:
– Closed systems can deliver near zero waste water all year round.
– Smaller footprints, therefore less impact on the natural environment.
– Marginal land is not an issue.
– Grow foreign plants in local climates.
– Controlled environment allows better use of IPM and beneficial insects with much reduced sprays.
– Higher Brix (sugar) levels deliver sweeter flavoursome fruit and longer shelf life.
– Year-round supply of consistent quality and quantity to meet consumers needs.
– Environmentally sound and responsible growing system.
– No weeds, no weeding, no herbicides!
– Higher production per hectare (1ha glasshouse produces the same as 9.4ha field).
– Higher returns for farmers’ efforts.

All Australian growers should aim to grow important consumer products in the most productive, efficient and environmentally responsible way and protected cropping systems clearly shine as the best option for a range of common consumer crops.

Forward thinking countries around the globe recognize and indeed utilize these technologies to great effect. Australian growers and politicians need to think beyond the square of traditional broad-acre farming and embrace this modern and efficient face of horticulture.

All farmers are encouraged to attend the 2007 biennial national AHGA conference in Launceston (24 -27 June – workshops, trade expo, farm visits) to discover how you too can enter this exciting and innovative industry.

About the author
Graeme Smith (CPAg) is the co-principal of Hydroponic Designs Pty Ltd, a Victorian-based national and international industry consultancy company, and President of the Australian Hydroponic & Greenhouse Association. Email:

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