R2114 Protected environments Flashcards
a. Two distinct protected structures.
b. Describe how each of above can be used for vegetable production.
a. Glasshouse, poly tunnel, cold frame, cloche etc
b. Glasshouse - can be used heated or unheated as needed for veg or flowers, eg tomatoes, cucumbers or chillies. Crop can be grown on bench or in ground using hydroculture. Poly tunnel - normally non-heated, but can be if required. Less flexible than a glasshouse. Potential of the growing season to be shorter and retains high levels of humidity. Can be used to grow celery, strawberries, raspberries, peppers lettuce.
Compare the aerial environments for each of the environmental factors as mentioned, inside protected environment and outside. Air temp, Humidity, air movement, carbon dioxide, natural light levels.
Environment-Outside-Protected
Air temp= Lower air temp - higher air temp
Relative Humidity= lower relative humidity - higher r. humidity
Air movement= Considerable - limited
Carbon dioxide= Ambient concentration - Lower concentration
Natural light= Higher levels - restricted levels
a. Two distinct cladding materials of protected structure
b. Four properties for each of the above named materials
a. Horticultural glass, polythene film. other eg’s twin walled polycarbonate, acrylic sheets, shade netting, horti fleece.
b. Horti glass - long life, heavy but string, fragile, high light transmission, retains heat. Polythene film - less expensive but limited life, does not retain heat, reduced light transmission compared to glass, deteriorates over time. Twin walled poly - more expensive, light weight, easier to shape, good heat retention and light transmission, may deteriorate over time.
a. Two named materials for growing media, for production of plants in protected environment.
b. Describe two environmental factors that must be taken into consideration for plants inside domestic buildings.
a. Shredded bark - non-clumping with open structure and good aeration. Bark can lock up nitrogen and has low water holding ability. The pH of bark can be varied. Perlite - is inert, durable, light and sterile. Improves drainage and air-filled porosity in a growing media. Water is only held on surface of the granule and it produces dust which is an irritant.
b. Natural light - influencing plant selection. Poor light results in etiolated growth, extended internodes and week growth, resulting in being susceptible to P&D. Variegated plants will require higher light levels. Flowering will require good light, and green plants tolerate shade. Air temp. - Individual plant require specific temperatures. Low temp results in poor weak growth and lack of flower. Excessive heat causing drying out of media and potential leaf damage. Fluctuating temp are more damaging resulting in very poor growth.
Describe the management of the following foliage plant (Ficus benjamina) for each of the following.
i) propagation. ii) potting. iii) watering. iv) one symptom of one pest.
i) Stem tip cutting. Healthy, true and P&D free. Removed from above a node, and then cut to under a node 5-7.5cm long, remove lower third of leaves. Root hormone powder if required. Placed in closed case, basal heat 21-24o and high humidity.
ii) Rooted cutting placed in 9cm pots with John Innes 2 or equivalent loam less media. Held in centre of half filled pot. Potted to same depth as cutting tray, growing media added gently until pot is full and gently firmed in.
iii) Initially watered from above to settle media. Moist conditions should be maintained, using can or tray.
iv) two spotted spider mite, causing local death of mesophyll cells. Resulting in leaf mottling. Fine silk strands also visible.
a. Describe one method of watering and two advantages.
b. Describe one automated method of watering and two limitations.
a. Watering can - provides a limited amount of water before requiring a refill. Single spout can be used to direct water to base of plant. Alternatively using a rose for a seed tray. Can be cheap to buy.
b. Drip irrigation - pipes transport water from mains near to the plant. Capillary tubes inserted into the pipes which are often attached to pots. Water is delivered as a drip to the base of the plant. Hard water areas may find fine tubes become blocked. Rabbits or other rodents can chew through the tubes.
a. Name four distinct protective structures used in horticulture for crop production, propagation or display.
b. Describe two horti. uses for each of the structures named in a.
a. Glasshouse, polythene tunnel, cold frame, cloche. (other. conservatory)
b. Glass house- Propagating plants, growing a main season crop, overwintering plants. Polytunnel- Grow a short season crop. Propagation and overwintering. Cold frame- Propagate hardy plants, growing and hardening off bedding plants . Cloche- Protect early season row crops, starting off runner beans until established.
a. State two reasons why adequate ventilation is an essential part of successfully growing under protection.
b. Describe one named method of ventilation.
a. i) Essential to maintain optimum air temp. for growing. Temp. that era too high can encourage soft growth which susceptible to P&D damage and low yield. Temp. that is too low can cause stunted growth, reduced flowers and yield. ii) Important to maintain ambient carbon dioxide in protected environment. Inadequate ventilation can cause temporary depletion of carbon dioxide around plant foliage resulting in lower yield.
b. Forced/Fan ventilation. Extractor fan installed at one end of the structure and an opening is constructed at the other. As hot moist air is extracted by the fan, cooler air enters slowly through the large opening. A range of ventilation rates can be achieved by the number of fans and their speed, controlled by a thermostat.
Describe the properties of the following hort. cladding materials for the following.
i) Horticultural glass ii) Polycarbonate iii) Polyethylene film iv) Acrylic sheets v) Horticultural fleece
i) Horticultural glass- Good natural light entry maintained for a long time. Heavy and fragile. ii) Polycarbonate usually twin wall- Very good insulator, does not break easy and can be cut with a saw. iii) Polyethylene film- limited life, can create condensation, wind and snow damage. iv) Acrylic sheets- Can be obtain in limited sizes and thickness, tends to discolour over time. v) Horticultural fleece- Reduces light levels creating a shade effect, does not retain heat, short term frost protection.
Describe one method of heating a protected structure under each of the following headings.
i) fuel used ii) heat distribution iii) efficiency of the system
i) Gas, oil, electricity, bio-fuel
ii) Heat can be distributed around the protected environment by air. This can be direct from a fan heater situated in one corner of the structure. It can also be distributed via polythene ducting which distributes the heat evenly within the structure. Warm air rises so heat source needs to be low down to ensure even heat distribution.
iii) Efficiency of the system is dependent on the reliability and effectiveness of the heat source combined with the ability to distribute the heat around the structure quickly. This is to ensure that the system is responsive to any temperature change. Financial efficiency is also important. max heat for min cost.
Describe the production of a named salad crop under each of the following.
i) Propagation ii) Planting iii) Plant maintenance
- Solanum Lycopersicum*
i) Propagate by seed, Clean/new seed tray is overfilled with John Innes seed compost, tapped and struck off, and firmed with a board. Seed sown evenly across surface and lightly covered with sieved compost. set in a heated propagator at 18-21o. Seedlings pricked out into 9-12cm pots.
ii) planted in grow bag, hydroculture, pots or directly in soil. Plants should selected for health and vigour, watered well, and handled with care. Planted at the same depth as in their pots.
iii) Water regularly to maintain field capacity, avoiding dry and wet cycles. Nitrogen feed to support growth, then potassium feed for flowering and fruit. Support provided by cane or string system. Lower leaves should be removed to maintain air flow around plant.
Describe details of Euphorbia pulcherrima (poinsettia)
Semi-evergreen shrub with large, bluntly toothed, ovate leaves and tiny yellow flowers with leaf-like bright red bracts, opening in winter. Grows up to 50cm. H1B min winter temp 13 oam-based potting compost with added bark and leaf mould in full light during winter, avoiding any draughts.
Propagate by stem cuttings in early summer. Use a hormone rooting compound.
Water sparingly during growth and apply a balanced liquid fertiliser every 10-14 days
Pests- Glasshouse red spider mite, glasshouse whitefly and mealybugs may occur
Diseases- grey moulds may be seen
Describe details of Saintpaulia ionantha (African violet)
Evergreen, rosette-forming, frost-tender perennial to 10cm tall. Two to eight violet-blue, tubular flowers up to 2.5cm across are held in loose clusters above the foliage all year-round. pH
Acid, Neutral. loamless potting compost on an east or west-facing windowsill.
Water sparingly as compost dries in winter and in the growing season water freely allowing compost to dry out between waterings; feed fortnightly with a high-potassium fertiliser
Propagate by leaf cuttings in summer
Pruning- Remove dead leaves
Diseases- Generally trouble free
