Paper 2/18

Question 1

horticultural structures to grow plants in:

Answer 1

Glasshouse
Conservatory
Polythene tunnel
Cold frame
Cloche

Question 2

Description of glasshouse including construction materials.

Answer 2

Framework - wooden or galvanised steel.
Glazing bars - wooden or aluminium to retain horticultural sheet glass.
Strip foundations and single concrete blocks.
Concrete ‘dollies’ supporting the gutter posts.

Question 3

Description of cold frame including construction materials:

Answer 3

Wooden frame retaining sheets of horticultural glass supported by brick walls or wooden frame.

Twin walled polycarbonate can be used for glazing instead of glass.

Question 4

Environmental factors that need to be controlled for ideal growing conditions:

Answer 4

Air temperature, 
relative humidity, 
light levels, 
carbon dioxide concentration, 
freedom from pests and diseases,
soil moisture content

Question 5

Effect on growth of low air temperature.

Answer 5

Low air temperature will slow down growth and photosynthesis.
Extreme low temperatures can cause frost damage.
Temperatures that are to high will slow growth.

Question 6

Effect on growth of humidity levels.

Answer 6

High relative humidity can increase the risk of fungal problems.
Water and nutrient levels can also be reduced.
Low relative humidity will increase the rate at which plants dry out.

Question 7

Controlling air temperature.

Answer 7

Heating during cold weather to maintain an optimum temperature.
Ventelation lowers relative humidity.
Damping down the floors in hot weather inside the protected structure.
Reducing ventilation increase relative humidity.

Question 8

Pests of decorative pot plants.

Answer 8

Aphids, whitefly, mealy bug, scale insect.

Question 9

Diseases that affect decorative pot plants.

Answer 9

Powdery mildew

Botrytis

Question 10

Benefits of cultural methods of controlling pest in a protected environment.

Answer 10

No pesticides are used which is better for the environment.

No need for clearance period before crops can be sent to market.

Question 11

Benefits of biological methods of controlling pest in a protected environment.

Answer 11

Can be very cost effective if balance between pest and predator can be achieved.
Pests will not build up resistance to pesticides.

Question 12

Limitations of cultural methods of controlling pest in a protected environment.

Answer 12

May not eradicate the pest.

May not be possible if pest is well established.

Question 13

Limitations of biological methods of controlling pest in a protected environment.

Answer 13

Timing of introduction of predator or parasite is critical.

Needs background presence of pest, which is not acceptable on plants being sold.

Question 14

Propagation of main season tomato crop:

Answer 14

Broadcast seed in a seed tray or use modules, one seed per module.
Use seed compost.
Germinate at temp 18 to 23 degrees C.
Prick out into modules or 9cm pots.
Handle carefully and avoid dehydration.

Question 15

Planting out and establishment of main season tomato crop:

Answer 15

Tomatoes can be planted in the ground within the protected structure, in raised beds, grow bags or into rock wool or Nutrient film technique as a hydroponic system.
Points or consider include depth of planting, firmness, careful handling and grading plants to maintain uniformity.
Supporting strings can be tied to the base of plants and suspended from the structure.

Question 16

Maintenance of main season tomato crop:

Answer 16

String the plants to allow for stem growth.
Deleafing the lower plant allows tomatoes to ripen and increases air movement to avoid fungal diseases.
Side shoots are removed to maintain a single growing point..
Water and feed as required.
Control ventilation to control relative humidity and maintain ambient CO2 levels.

Question 17

Saintpaulia ionantha - potting up from a leaf petiole cutting.

Answer 17

Pot separately in 9 or 10cm pot to avoid multi crowned plants.
Use potting compost such a John Innes no 1.
Do not bury the central growing point of the plant.
Centralise plant in pot.
Handle plant with care.
Water in to settle compost around roots without wetting leaves.

Question 18

Saintpaulia ionantha - watering

Answer 18

When first planted or re-potted the plant should be watered from above to settle soil around roots, care should be taken to avoid getting water on the leaves.

After that the plant should be waters from below, the plant will take up water by capillary action.
Alternatively a drip irrigation system can be used bellow the canopy of folliage.
Ideally use rain water to avoid lime build up.

Question 19

Saintpaulia ionantha - feeding.

Answer 19

Can be fed by a base dressing incorporated into the compost to include a range of slow release nutrients.
Liquid feed can be included through the irrigation system, may contain specific nutrient eg. Potassium to encourage flowering.

Question 20

Uses of a cloche

Answer 20

Covering a low growing soft fruit.

Overwintering a single small plant.

Question 21

Uses of a cold frame.

Answer 21

Hardening off

Forcing bulbs.

Question 22

Uses of a conservatory.

Answer 22

Displaying flowering and foliage plants.

Question 23

Uses of walk in polythene tunnel.

Answer 23

Establishing a row of salad crops.

Production of a cut flower crop.

Question 24

Use of glasshouse.

Answer 24

Growing main season tomato crop.
Growing a crop of Poinsettias.
Propagating young bedding plants in modular containers.