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
n 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.
