Pak Choi Handbook

Nutrient Film Stage

Environmental Set Points

Day 10 - Transplanting
On the tenth day after sowing the pak choi, 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 14 inches (35.6 cm) along the length of the trough. Therefore, each plant occupies 42 square inches (270 cm ²) and have a density of 3.45 plants per square foot or 37 plants per square meter.

Environmental Set Points

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

Day 16

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

Note: The photo above shows empty troughs between plant-carrying ones. This is due to spacing experiment arrangement. In production conditions each trough carries plants spaced twice as far as in above photograph.

Day 17 - Respacing
Leaves of the growing pak choi 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: The photo above shows empty troughs between plant-carrying ones. This is due to spacing experiment arrangement. In production conditions these empty troughs would be removed as described in the paragraph above.

Day 21

Growth chamber pak choi grown in relatively low light conditions (200 micromole m^-2s^-1).

Day 24

Day 27

Growth chamber pak choi plants grown in relatively high light conditions (400 micromole m^-2s^-1)

Day 29

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

Day 35 - Harvest

Five weeks from sowing pak NFT-grown pak choi plants are ready for harvest.