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Spinach Handbook


 

Nutrient Film Stage

Environmental Set Points

Day 8 - Transplanting
On the eighth day after seeding the spinach, the seedlings are transplanted from the germination area to the glasshouse. Each seedling is manually transplanted into a Nutrient Film Technique (NFT) trough. The troughs, which are 3 inches (7.6 cm) wide, are set adjacent to each other with no space between the troughs. Holes for setting the plants into are 7 inches (17.8 cm) along the length of the trough. Therefore, each plant occupies 21 square inches (135 cm 2) and have a density of 6.9 plants per square foot or 74 plants per square meter.

Environmental Set Points

Day Temperature 25o C (77o F)
Night Temperature 20o C (68o F)
pH 5.8
EC 1.2 milliSiemens/cm
Dissolved Oxygen at least 4 mg/liter
Accumulated Light up to 17 mol m-2d-1
Relative Humidity between 30 and 70%

Growing conditions remain at these set-points during the entire nutrient film growth stage.


Day 16


Note the close space NFT troughs

On day 16 the spinach seedlings are beginning to fill the canopy. Theymust be spaced further apart, before the leaves become tightly entangled with each other and cause damage to the plants during respacing.


Day 18 - Respacing
Leaves of the growing spinach plants are beginning to interfere with the growth of adjacent plants. Every other trough is removed and respaced to achieve a three inches (7.6 cm) space. The space occupied by each plant will double and the density reduced in half. This spacing is maintained for the remainder of the plants stay in the glasshouse.


Note increased spacing between troughs


Day 20


Day 24

During our tests, harvests were made frequently, usually one or two times per week from the beginning of the test until the end. In that way we were able to track the weight of the plants over their life span. The empty trays in the photographs above held plants already harvested.


Day 26


Test crop in high light environment


Day 30

Rapidly, the canopy seems to be completely filled. The plants are continuing to add weight.

 


Updated: 06/17/2004 01:29 PM
If you have questions about Controlled Environment Agriculture, please contact Professor Louis Albright